Revisions for Spectrometry Sampling
| 27 CURRENT | warren |
November 20, 2017 22:06
| about 7 years ago
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Questions[questions:spectrometry-sampling] Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. There are lots of different affordable test tubes on Amazon, but they're mostly round. Flat-sided test tubes are often called cuvettes and are specifically for spectrometry. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
Oil samplingHowever, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments.
To identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date can be found on the Oil Testing Kit page
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
Activities[activities:spectrometry-sampling] |
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| 26 | warren |
May 08, 2017 15:19
| over 7 years ago
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. We're working to expand this section with more resources, so please help out by asking questions here, and posting under the tag [questions:spectrometry-sampling] Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
Oil samplingHowever, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments.
To identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date can be found on the Oil Testing Kit page
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
Activities[activities:spectrometry-sampling] |
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| 25 | warren |
May 08, 2017 14:40
| over 7 years ago
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. We're working to expand this section with more resources, so please help out by asking questions here, and posting under the tag [questions:spectrometry-sampling] Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
Oil samplingHowever, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments.
To identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date can be found on the Oil Testing Kit page
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
[activities:spectrometry-sampling] |
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| 24 | warren |
May 08, 2017 14:39
| over 7 years ago
Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
Oil samplingHowever, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments.
To identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date can be found on the Oil Testing Kit page
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
[activities:spectrometry-sampling] |
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| 23 | warren |
May 08, 2017 14:38
| over 7 years ago
Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
Oil samplingHowever, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments.
To identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date can be found on the Oil Testing Kit page
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 22 | warren |
May 08, 2017 14:37
| over 7 years ago
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
Oil samplingHowever, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments.
To identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date can be found on the Oil Testing Kit page
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 21 | OpenSourceScience |
March 11, 2015 19:36
| almost 10 years ago
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
Oil samplingHowever, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments.
To identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date can be found on the Oil Testing Kit page
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 20 | warren |
July 24, 2014 20:03
| over 10 years ago
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
Oil samplingHowever, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments.
To identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date can be found on the Oil Testing Kit page
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 19 | warren |
July 24, 2014 19:48
| over 10 years ago
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Ultraviolet light illuminating a sample of extra virgin olive oil (left) and BP crude oil residue dissolved in mineral oil (right)
Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date can be found on the Oil Testing Kit page
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 18 | warren |
December 18, 2013 16:27
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Ultraviolet light illuminating a sample of extra virgin olive oil (left) and BP crude oil residue dissolved in mineral oil (right) Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Recent successes:
Ongoing research questions include:
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 17 | warren |
December 18, 2013 16:27
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Other sample container options
Water is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Ultraviolet light illuminating a sample of extra virgin olive oil (left) and BP crude oil residue dissolved in mineral oil (right) Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Recent successes:
Ongoing research questions include:
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 16 | warren |
December 14, 2013 17:27
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Ultraviolet light illuminating a sample of extra virgin olive oil (left) and BP crude oil residue dissolved in mineral oil (right) Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Recent successes:
Ongoing research questions include:
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 15 | warren |
December 14, 2013 17:25
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Ultraviolet light illuminating a sample of extra virgin olive oil (left) and BP crude oil residue dissolved in mineral oil (right) Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Recent successes:
Ongoing research questions include:
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 14 | warren |
November 09, 2013 15:26
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Unfortunately, we've found that cuvettes with plastic stoppers will leak when filled with oil and not kept upright (for example if you travel with them). A really nice source of completely sealable rectangular 1/4 oz glass jars which are pretty perfect for sampling can be found for $3.50 for a ten-pack here (see image below of 2 on top of a flashlight): http://www.sciplus.com/p/WHITCAP-BOTTLE_48212 Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Ultraviolet light illuminating a sample of extra virgin olive oil (left) and BP crude oil residue dissolved in mineral oil (right) Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Read more about this process at this note by Scott Eustis: http://publiclab.org/notes/eustatic/08-01-2013/making-grand-isle-coffee Ongoing research questions include:
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 13 | warren |
October 09, 2013 16:44
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Ultraviolet light illuminating a sample of extra virgin olive oil (left) and BP crude oil residue dissolved in mineral oil (right) Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Read more about this process at this note by Scott Eustis: http://publiclab.org/notes/eustatic/08-01-2013/making-grand-isle-coffee Ongoing research questions include:
Burning potato chips to measure the sodium emission spectrum from the NaCl (salt). Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 12 | warren |
October 09, 2013 16:43
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia). Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Read more about this process at this note by Scott Eustis: http://publiclab.org/notes/eustatic/08-01-2013/making-grand-isle-coffee Ongoing research questions include:
Ultraviolet light illuminating a sample of extra virgin olive oil (left) and BP crude oil residue dissolved in mineral oil (right) Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 11 | warren |
October 09, 2013 16:37
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia. Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Read more about this process at this note by Scott Eustis: http://publiclab.org/notes/eustatic/08-01-2013/making-grand-isle-coffee Ongoing research questions include:
Flame spectroscopyAnother type of spectrometry which involves measuring the light of a flame and can detect specific elements (not molecules) as they emit light at very specific "peaks" -- narrow wavelength bands. Besides flames, these "emission lines" can be produced by exposing gases or sometimes liquids to UV light, lasers, or electric fields (as in a fluorescent bulb). The fluorescent bulb spectrum you get when calibrating is an example of a mercury emission spectrum. Emission lines are produced by atoms, not whole molecules (the latter produce absorption lines, which we might still be able to detect since we have the flame -- a good broad-spectrum light source -- but that is just a theory at this point). So sulfur and carbon are possible targets, but we won't be able to distinguish CO2 from CO. Basic setup: For a more complete description, please read about the "flare spectroscopy activity" below, however, the basic setup involves simply pointing a spectrometer at a flame (which can be difficult to line up if the flame is far away), and later comparing any peaks to known peak locations of looked-for elements. We are compiling a collection of such known elements by importing "idealized" spectra from the NIST database, a process which you can read more about here. Read more about flame spectroscopy:
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| 10 | warren |
October 06, 2013 14:45
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia. Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Read more about this process at this note by Scott Eustis: http://publiclab.org/notes/eustatic/08-01-2013/making-grand-isle-coffee Ongoing research questions include:
...more soon... |
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| 9 | warren |
October 06, 2013 14:42
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia. Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow, as pictured above. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Read more about this process at this note by Scott Eustis: http://publiclab.org/notes/eustatic/08-01-2013/making-grand-isle-coffee Ongoing research questions include:
...more soon... |
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| 8 | warren |
October 06, 2013 00:59
| about 11 years ago
This page is under development.
How do you test liquid or solid samples with your DIY Spectrometer? Read about ways to prepare and scan samples here, and read about different tests you can do with your spectrometer. Sample containersWhat do you store liquid samples in? A good sample container has flat sides, so you can shine lights (and lasers) through it without lots of reflections. It's also good to have the light travel through a consistent amount of the sample -- many cuvettes (traditional spectrometry sample containers) are 1cm x 1cm, so the light always goes through 1cm of the sample.
A square-sided bottle, left, and a cuvette, right (photo from Wikipedia. Water samplingWater is usually very clear in small amounts -- even murky water in a small container will look pretty transparent. That makes it hard to measure with spectrometry unless you shine light through a lot of it. But some tests have been done -- see this example of a scan of water from the Charles River before and after 7 days of settling, by Jeff Hecht:
However, most research in Public Lab to date has focused on oil spectroscopy -- attempting to identify petroleum residue in sediments. Read on to learn more!
Oil samplingTo identify oil contamination, we have been attempting to illuminate oil samples with UV flashlights and green lasers, which can make some oils fluoresce, or glow. The basics of sample preparation for oil identification are still being refined, but our best practices to date are:
Read more about this process at this note by Scott Eustis: http://publiclab.org/notes/eustatic/08-01-2013/making-grand-isle-coffee ...more soon... |
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