Chromatography Forum

To check out a non-Agilent detector, I need to get the scale on my HPLC A/D ChemStation to be in millivolts, so I can check the detector drift and noise to be 3 mV or less. Right now, the axis has no units at all, like maybe it's Area Counts, maybe something else. Any way to get what I need? The unit in question has ChemStation A.06.03, but I can move the detector to a system with A.09.01 if necessary. I also have a 3392 integrator available, and could set that up to the detector (which has three output voltages), I just don't know what it's scaling would be either.

I'm probably missing something, but wouldn't you go ( from the main menu ):- Instrument, Setup ADC Signal, Unit = mV, Units/volt = 1000 ?.

It may depend on your A->D converter, but that's my recollection from a 35900D and Chemstation 5.01 to 8.3. We used do similar ( but x1000 for uV ), and then have uV on the axis.

If not, I probably have an old manual around somewhere, but may need to know the A->D model.

Good luck, and please keep having fun.

Bruce Hamilton

Bruce -you're correct, and I already got that information from Alltech on how to set that up. But since I'm NOT a computer guy, I had tried the ChemStation online help (which usually doesn't help, and didn't help here, was unclear); I didn't look in the manual for additional help, but I did speak with a Walter at Agilent Help, who then told me there was no way. Then I received a follow-up E-mail from Alltech (I was using their detector and wanted to measure the noise with the ChemStation) who told me essentially what you did. We had always used the A/D with no unit scaling and the default number for Units/Volt, and it never dawned on me (Duh !!!) that I should simply enter 1000 to force as 1000 units or millivolts per volt, and could also right above it enter "mV" as that was just a character box. Thanks, so after using ChemStation software for 16 years, learned something new (again). Any thoughts on how to fix the glitch when doing Sequence Summary Reports (Compound Summary) doing %ESTD so that the heading over the results column defaults to "%" like it did in A.03 instead of just copying whatever units one has entered in for "Sample Amt" (glitch extends to at least A.09)? The answers are correct, one has to either ignore the heading or fix in Notepad and re-print.