First of all, thank you for addressing the topic (here and also from May 16, 2023).
It is very important that, alongside numerous incorrect explanations, there are also good, independent, and scientifically based explanations regarding the alleged UVC effect available on the web. I will be happy to refer to it again in future inquiries about “solar UVC radiation at ground level.”
Ralf Zuber has already written quite a bit about the BTS and its measurements. However, if I wanted to demonstrate the "UVC effect" at our measurement stations in Germany, I would indeed also use a BTS device. It very easily allows me to demonstrate the effect with high spectral resolution in the spectra by simply switching off the stray light correction, all within a few minutes. Of course, this would not be a correct use of the BTS!! I would probably not be able to produce the effect much better with a monochromator, just with greater effort.
You have summarized everything else about the BTS measurements well in your new post from January 10 titled "Clarification." I might write an additional comment in that section.
which measurement mode did you use? Since you show measurement data down to 200 nm the measurement mode without stray light correction must be used. There are several measureemnt modes provided in the meter. Some without filters for fast measurements as this one down to 200 nm, however low stray light reduction. The ones with stray light reduction based on bandpass filter stray light reduction methods delivers data only down to 280 nm. This mode is called solar BP measurement mode. Only this measurement mode used for solar measurements with the high spectral stray light reduction.
I can just recommend to use this methode for solar measurement. This is shown in many papers, see:
Hence the comparison what you performed is based on data with a not suited measurement mode for solar measurements. Do you may want to repeat this measurement with the suited mode?
I'm happy to discuss your measurement results direclty.
First of all, thank you for addressing the topic (here and also from May 16, 2023).
It is very important that, alongside numerous incorrect explanations, there are also good, independent, and scientifically based explanations regarding the alleged UVC effect available on the web. I will be happy to refer to it again in future inquiries about “solar UVC radiation at ground level.”
Ralf Zuber has already written quite a bit about the BTS and its measurements. However, if I wanted to demonstrate the "UVC effect" at our measurement stations in Germany, I would indeed also use a BTS device. It very easily allows me to demonstrate the effect with high spectral resolution in the spectra by simply switching off the stray light correction, all within a few minutes. Of course, this would not be a correct use of the BTS!! I would probably not be able to produce the effect much better with a monochromator, just with greater effort.
You have summarized everything else about the BTS measurements well in your new post from January 10 titled "Clarification." I might write an additional comment in that section.
Dear Mr. McKenzie,
which measurement mode did you use? Since you show measurement data down to 200 nm the measurement mode without stray light correction must be used. There are several measureemnt modes provided in the meter. Some without filters for fast measurements as this one down to 200 nm, however low stray light reduction. The ones with stray light reduction based on bandpass filter stray light reduction methods delivers data only down to 280 nm. This mode is called solar BP measurement mode. Only this measurement mode used for solar measurements with the high spectral stray light reduction.
I can just recommend to use this methode for solar measurement. This is shown in many papers, see:
DOI 10.1088/1361-6501/aada34
https://doi.org/10.5194/amt-11-2477-2018
https://doi.org/10.5194/amt-14-4915-2021
Hence the comparison what you performed is based on data with a not suited measurement mode for solar measurements. Do you may want to repeat this measurement with the suited mode?
I'm happy to discuss your measurement results direclty.