Ghost data in buffer

[Dave_VUB]

Hi, I am trying to get decent results from the build kit but I am getting some strange results. It seems like some unwanted data keeps getting through the data accumulation. The data that I am talking about is still visible even when the laser is turned off. Is this correct or is there some kind of problem here?

[Luc]

different origin are possible but I'm thinking of those two first:

• stray light in the room, in particular if you use fluorescent lamps or if your setup is close to a computer monitor or TV
• hot pixels; some pixels will have higher response than others

In both case you can compensate by using a blank taken in the same operating conditions with the same exposure/gain settings. I always use a blank for my measurements, even when calibrating with a Neon lamp.

[Dave_VUB]

Is a blank just the environment (with or without the laser source turned on) or is it taken with an empty cuvet for example to simulate everything that is reflected onto the sensor apart from the sample itself?

[Luc]

My recommendation is to take the blank exactly like how you'd do the measurement but just switch the laser off - then switch the laser back on, wait for stabilization if required, and perform all your measurements.

So I do it with the test tube in place And I even try to stay at the same position in the room in case I would block some light from PC monitor or else. It's a bit overkill but I prefer doing more than not enough!

[Dave_VUB]

Hi I tried the blank removal as you mentioned for Methanol. The results I get with and without the blank removal are as follows (filenames with 1100 is with blank removal, filenames with 1105 are without blank removal)

[Dave_VUB]

some settings I used are:
- exposure 4s
- gain 2dB
- baseline removal alg enabled

[Luc]

Is the setup at the VUB main campus in Etterbeek?

If so, maybe we can arrange a visit so that I have a look at your setup directly. Contact me via private message if you're interested.

[Dave_VUB]

Hi, I would love to have a personal visit if possible