Testing the new spectrometer in ultraviolet!
Added 2020-05-23 16:53:06 +0000 UTCIn my next video, I will test the wavelength of all the laser colors I have in my collection. I will use the new spectrometer unboxed in the last Patreon video.
It will therefore also be a precision test of the spectrometer in the visible and infrared spectrum.
But I do not have any invisible UV lasers, so to give you and me an idea of the spectrometer's performance in the ultraviolet spectrum, I made this video. Enjoy.
You may need to pause the video at some places in the final part - the editing got a little rushed. I need every minute for the upcoming video which is a rather big project - once again... Not only do I test the wavelength but also the power of the strongest laser for all my laser colors!
I will even test if the Laserglow Hercules-400 still emits over 400 mW. Will it after 12 years and being bought second-hand? I am nervous about it. I will make a poll to see what you expect...
Next public video coming Saturday, 30th of May.
Comments
Hehe, Big Clive sure has been on a scammer hunt lately to find the doubtful UV lights being sold as germicidal etc. during the pandemic. I am pleased to see, they used the right, more expensive glass type in mine. I was surprised by the strength of the UVC output compared to the strength of the visible output. Glad I have been careful with it!
2020-05-25 16:33:03 +0000 UTCWell done for finding a real UVC bulb on eBay rather than one of the many fakes that bigclivedotcom has been reviewing lately!
Kathy M
2020-05-24 20:21:45 +0000 UTCShort answer: It is reading the background light too, but too little. The main reason is that it uses a glass fiber cable to guide light into the spectrometer where the actual sensor is placed. The glass fiber uses full internal reflection to guide the light and this only works for light coming in at small angles. Only what's right in front of it, not from the sides. So the fiber solution is good for pinpointing light sources. The cable does come with a 'cosine corrector' which is a fancy word for a diffuser I can put in front of the fiber cable, so light coming from the sides is also measured. Besides pinpointing the light source I also keep the exposure time low (10 milliseconds) so only strong light sources are detected. The stray background light being reflected into the spectrometer is not strong enough to be noticed over the sensor's black noise. In my upcoming video you will notice on the weaker lasers (where I have to use longer exposure time) that the background light is indeed picked up too. So you are thinking in the right way. For truly scientific use I would have to blacken the room for analysis of weak light sources. It is just not very video friendly ;) We prefer to see what is happening.
2020-05-24 08:48:35 +0000 UTCWhat keeps it from reading the background light?
2020-05-24 02:39:21 +0000 UTCI always think in nanometers when dealing with electromagnetic radiation in the ultraviolet to infrared spectrum. It is just tradition. But you're right, the wavelengths have a corresponding frequency. It is the opposite with sound. Here we always measure in frequency and would be confused if we used wavelength in stead. Human hearing goes from 17 meters to 17 millimeters in wavelength ;)
2020-05-23 20:07:45 +0000 UTCGood question, I am not sure either. I think it's a relative value. It will be higher if I set the exposure time to be longer, but I haven't looked into if the value in 'uW/cm^2/nm' is unchanged from longer exposure time. I am still learning to use the spectrometer and program :)
2020-05-23 19:55:53 +0000 UTCI don't know if it would be helpful, but for some displaying the frequency aswell might be interesting. Showing the relationship between the two. You never know you could save a cell tower. (5g joke)
2020-05-23 18:49:13 +0000 UTCNeat! I might have missed it (and the spectrometer program doesn't seem to tell) but what is the unit for the Y axis?
Peter Brodersen
2020-05-23 18:21:52 +0000 UTC
