Thank you for the wonderful tutorial! I have a question about the transmission measurement with slits by integrating sphere. You mentioned put the slit in the sample location, but do you need to put slit in the reference beam location as well? I'm somewhat confused about where to put slit for the reference beam and for actual sample measurement.
We don't currently recommend putting a slit in the reference beam location. Our "slits" are actually just thick pieces of magnet from which we've cut holes of different sizes. Because of their glossy surface, they do reflect some light, and can cause reflectance values greater than 100%. By narrowing the beam down in the transmission space, the beam that hits the reflectance side is also altered. If a person is interested in reflectance data, we recommend they turn on the "align" mode, then chose and position a transmission slit so that the beam hitting the back of the integrating sphere (in the R position) is the right size and shape for the sample in question.
Hello , Thanks for this video. I want to measurement at 800-1000nm R but monochromator changes at 890 nm ( max value is 900nm) so I get very noisy measurements between 890-1000nm. because of the slit width pass. what should I do ?
We have had that same issue repeatedly on our instrument as well. In the past, depending on the age of the W bulb, changing that lamp can sometimes help smooth things in that area. I believe you can also experiment with the gain and response settings in the detector settings on the schematic page of the method setup. I don't have much experience with how to change those settings, but it has been recommended to us by Perkin Elmer. Since the detector and the monochromator change at the same time, adjusting the relevant detector can help smooth that noise as well
Thank you for sharing valueable information and tutorial. I am beginner to to use this instrument and have following questions: 1. Is there any way to measure absorption with this instrument? 2. I was reading article from internet to extract information from R and T data. Is there any other way? Thanks alot for your followup. Best Regards
Hi, so sorry we didn't see this comment sooner! Absorption can be measured using reflectance and transmittance, as you mentioned. Many times, users will make the assumption that one of those is nonexistent (such as with a very thick sample, there is little or no T). In that case, R and A would be inverse of one another. The same is true if you assume no R (A and T would be inverse). Those are the most common ways one could find exact absorbance with this machine.
Hi Ricardo, I'm sorry to hear that your computer crashed. We purchased our (Windows 10) software in 2020 from Perkin Elmer. I know they don't directly support some aspects of the Lambda 950 anymore, but they still make WinLab for their other Lambda series (850 and 1050). You should be able to reach out to them to purchase a new license for your machine. Since we paid for our license, I don't feel comfortable sharing it outside of our lab. Best of luck!
You're hoping to use BaSO4 as the reference material? There are a few ways to handle reflection baselines. The first is with the typical 100/0% baselines I talk about in the video (just after minute 30). When running those, put your BaSO4 material in the reflection port in place of the spectralon standard provided. To take it a step further, you can also use the Reflection Corrections section underneath the 100/0% baseline section. I don't have much experience with those corrections, but they would help you differentiate between a specular (like a mirror) or a diffuse (like BaSO4) reflector.
@@materialscharacterization4168 Yes, this is exactly why I ask. Thank you for answering. I basically wanted to record a baseline measurement with BaSO4 (use it as a reference) and then measure the sample, but I was confused about one thing. Should my sample be also mixed with BaSO4 (both in powder form of course) or does my sample not need BaSO4 for the measurement anymore after the baseline? In this case, what was the reason for the BaSO4 in the first place? Was it to let the detector know the maximum diffuse reflection it can get from the BaSO4 or for which reason exactly? I think this confusion comes from thinking about the UV vis as an extension to the KBr - FTIR measurement. I thought it would be the same principle with the sample being disperesed in a matrix of the background (The KBr).
@@mahmoudsorour2028 I can see how that would be confusing. The KBr and BaSO4 are working in completely different capacities here. KBr is invisible to IR light, which is why it's used in FTIR. BaSO4 is (nearly) 100% reflective (so the opposite of invisible) and is merely used to define where 100% lies. If you think in terms of physics, there's no such thing as "100% light." It has to be a relative measurement, and you're using BaSO4 as the reference point. Your sample should, usually, not be diluted with the BaSO4. Hopefully that cleared it up!
@@materialscharacterization4168 All clear now. Thank you so much for your time. Appreciate it. I thought about it today in the morning and reached the same conclusion. Glad to have the confirmation from you. Thank you again and have a nice one!
@@pattabhidyta7991 I am not 100% sure, but I don't think so. The URA uses a system of mirrors to reflect the light at incident angles between 8 and 65 degrees to the sample surface. I don't think it uses an integrating sphere to collect that data; I think it's more mirrors that direct the light to the detector.
@@materialscharacterization4168 Thank you. Also wanted to know, What would be the power output of the light through the transmittance port of the integrating sphere? Is it good enough to place a fruit (say an apple) ?
@@pattabhidyta7991 So sorry I didn't see this until now. I believe the Lambda 950 is meant to handle ~6 OD, which means that 1 photon for every 1,000,000 photons gets through the sample. If the slice of apple was thin enough to allow at least that much light through, it could be analyzed. Since the transmittance of light through an entire apple is 0, that would not be possible. In that case, a sort of reflectance measurement would be the best option.
Hi! Thanks for the useful and informative tutorial. Could you please help me with my task? I have to measure absorbance spectrum of my sample (it is powder). How correct is it to choose "A" (absorbance) instead of "%R" as an ordinate mode in "Data Collection" window for reflectivity measurement?
Hi! The basic principle is that T+A+R=100% of the light. If you assume there is no transmittance (T=0) then A and R can be directly equal. In the case of a thick pellet of powder, you can assume there is no light transmitted through the sample, so it should be ok to change between A and %R and have them both be correct. Just keep in mind that the machine is measuring %R and calculating A.
@@materialscharacterization4168 I've tried to measure and compare the same sample in two modes: A and R. The results showed that the peaks in the spectrum obtained in R mode are much wider than in A mode, however the positions of the peaks didn't change. Using Kubelka-Munk transformation makes the peaks even narrower. Which option, in your opinion, is more correct?
@@user-jq2kg4hl6o Without being involved in your analysis and knowing the parameters of your material and the machine you're using, I am unable to comment on which method is more correct. You would probably do best to find a materials-trained person in your research facility to discuss the results with them.
Plzz mam make lectures on HPLC and gas chromatography
Unfortunately, we don't own either of those instruments, so we won't be doing those techniques.
Thank you for the wonderful tutorial! I have a question about the transmission measurement with slits by integrating sphere. You mentioned put the slit in the sample location, but do you need to put slit in the reference beam location as well? I'm somewhat confused about where to put slit for the reference beam and for actual sample measurement.
We don't currently recommend putting a slit in the reference beam location. Our "slits" are actually just thick pieces of magnet from which we've cut holes of different sizes. Because of their glossy surface, they do reflect some light, and can cause reflectance values greater than 100%. By narrowing the beam down in the transmission space, the beam that hits the reflectance side is also altered. If a person is interested in reflectance data, we recommend they turn on the "align" mode, then chose and position a transmission slit so that the beam hitting the back of the integrating sphere (in the R position) is the right size and shape for the sample in question.
Hello , Thanks for this video. I want to measurement at 800-1000nm R but monochromator changes at 890 nm ( max value is 900nm) so I get very noisy measurements between 890-1000nm. because of the slit width pass. what should I do ?
We have had that same issue repeatedly on our instrument as well. In the past, depending on the age of the W bulb, changing that lamp can sometimes help smooth things in that area. I believe you can also experiment with the gain and response settings in the detector settings on the schematic page of the method setup. I don't have much experience with how to change those settings, but it has been recommended to us by Perkin Elmer. Since the detector and the monochromator change at the same time, adjusting the relevant detector can help smooth that noise as well
Thank you for sharing valueable information and tutorial.
I am beginner to to use this instrument and have following questions:
1. Is there any way to measure absorption with this instrument?
2. I was reading article from internet to extract information from R and T data. Is there any other way?
Thanks alot for your followup.
Best Regards
Hi, so sorry we didn't see this comment sooner! Absorption can be measured using reflectance and transmittance, as you mentioned. Many times, users will make the assumption that one of those is nonexistent (such as with a very thick sample, there is little or no T). In that case, R and A would be inverse of one another. The same is true if you assume no R (A and T would be inverse). Those are the most common ways one could find exact absorbance with this machine.
Hi, could share you software? on my university we have the same model, the computer crashes and Perkin Elmer doesnt have anymore the software.
Hi Ricardo, I'm sorry to hear that your computer crashed. We purchased our (Windows 10) software in 2020 from Perkin Elmer. I know they don't directly support some aspects of the Lambda 950 anymore, but they still make WinLab for their other Lambda series (850 and 1050). You should be able to reach out to them to purchase a new license for your machine. Since we paid for our license, I don't feel comfortable sharing it outside of our lab. Best of luck!
Do you have any resources on how to measure a sample with a BaSO4 baseline in reflection mode?
You're hoping to use BaSO4 as the reference material? There are a few ways to handle reflection baselines. The first is with the typical 100/0% baselines I talk about in the video (just after minute 30). When running those, put your BaSO4 material in the reflection port in place of the spectralon standard provided. To take it a step further, you can also use the Reflection Corrections section underneath the 100/0% baseline section. I don't have much experience with those corrections, but they would help you differentiate between a specular (like a mirror) or a diffuse (like BaSO4) reflector.
@@materialscharacterization4168 Yes, this is exactly why I ask. Thank you for answering. I basically wanted to record a baseline measurement with BaSO4 (use it as a reference) and then measure the sample, but I was confused about one thing. Should my sample be also mixed with BaSO4 (both in powder form of course) or does my sample not need BaSO4 for the measurement anymore after the baseline? In this case, what was the reason for the BaSO4 in the first place? Was it to let the detector know the maximum diffuse reflection it can get from the BaSO4 or for which reason exactly?
I think this confusion comes from thinking about the UV vis as an extension to the KBr - FTIR measurement. I thought it would be the same principle with the sample being disperesed in a matrix of the background (The KBr).
@@mahmoudsorour2028 I can see how that would be confusing. The KBr and BaSO4 are working in completely different capacities here. KBr is invisible to IR light, which is why it's used in FTIR. BaSO4 is (nearly) 100% reflective (so the opposite of invisible) and is merely used to define where 100% lies. If you think in terms of physics, there's no such thing as "100% light." It has to be a relative measurement, and you're using BaSO4 as the reference point. Your sample should, usually, not be diluted with the BaSO4. Hopefully that cleared it up!
@@materialscharacterization4168 All clear now. Thank you so much for your time. Appreciate it. I thought about it today in the morning and reached the same conclusion. Glad to have the confirmation from you. Thank you again and have a nice one!
how much cost it?
You can find our hourly rates for using the equipment at mcl.mse.utah.edu.
Please make a tutorial on measurement with URA.
Hi Mohammad - that tutorial is in the works. We're hoping to have additional material for all of our machines sometime in 2021.
@@materialscharacterization4168 Hi, Is there an integrating sphere underneath the URA ?
@@pattabhidyta7991 I am not 100% sure, but I don't think so. The URA uses a system of mirrors to reflect the light at incident angles between 8 and 65 degrees to the sample surface. I don't think it uses an integrating sphere to collect that data; I think it's more mirrors that direct the light to the detector.
@@materialscharacterization4168 Thank you. Also wanted to know, What would be the power output of the light through the transmittance port of the integrating sphere? Is it good enough to place a fruit (say an apple) ?
@@pattabhidyta7991 So sorry I didn't see this until now. I believe the Lambda 950 is meant to handle ~6 OD, which means that 1 photon for every 1,000,000 photons gets through the sample. If the slice of apple was thin enough to allow at least that much light through, it could be analyzed. Since the transmittance of light through an entire apple is 0, that would not be possible. In that case, a sort of reflectance measurement would be the best option.
Hi! Thanks for the useful and informative tutorial. Could you please help me with my task? I have to measure absorbance spectrum of my sample (it is powder). How correct is it to choose "A" (absorbance) instead of "%R" as an ordinate mode in "Data Collection" window for reflectivity measurement?
Hi! The basic principle is that T+A+R=100% of the light. If you assume there is no transmittance (T=0) then A and R can be directly equal. In the case of a thick pellet of powder, you can assume there is no light transmitted through the sample, so it should be ok to change between A and %R and have them both be correct. Just keep in mind that the machine is measuring %R and calculating A.
@@materialscharacterization4168 I've tried to measure and compare the same sample in two modes: A and R. The results showed that the peaks in the spectrum obtained in R mode are much wider than in A mode, however the positions of the peaks didn't change. Using Kubelka-Munk transformation makes the peaks even narrower. Which option, in your opinion, is more correct?
@@user-jq2kg4hl6o Without being involved in your analysis and knowing the parameters of your material and the machine you're using, I am unable to comment on which method is more correct. You would probably do best to find a materials-trained person in your research facility to discuss the results with them.
@@materialscharacterization4168 Thanks for the answer.
you need to adjust the content