Reviving a Varian 3800 GC/FID - problems with Star 4.5

[ariel.grostern]

Hello,
I inherited a Varian 3800 GC/FID with Star Chromatography workstation 4.5. I am trying to get it to work for manual injections.

The instrument shows up on the Star software, and I can control oven, injector and detector conditions on the GC.

However, when I load the method, I get an error message that is summarized as:

"cannot find minimum.mth for startup.mth". When I start a run, the signal does not appear on the plot, and I cannot do any analysis (although on the GC display I can see the FID signal).

I have searched the computer for minimum.mth, and it is there. So I don't know why the computer is not finding it (i can't find in any of the settings if a directory must be specified).

I am tempted to uninstall the software and re-install Star 4.5 from diskette, but am afraid to mess anything up (i have already tried and failed to re-install the 8100 autosampler....).

Does anyone know anything about minimum.mth and startup.mth?

Thanks,
Ariel

[Ultimate Science 101]

Ariel --

That is a very peculiar error message. I have never seen another method "required" for one particular method to activate. At this point, I would suggest opening the startup.mth method in Workstation method builder. If you are not seeing the FID signal in Workstation, you most likely don't have it acquiring data. In the method builder, under the detector section, ensure that the FID electronics are turned on and also that the FID oven is on (probably 250-300C depending upon your application). You can set the air & hydrogen makeup flows as well in this section, unless you have a FID with manual pneumatics. Be sure to set the other parameters of your method accordingly such as oven temperature, column flow, injector temperature/split, etc. Save the method with a new name. Reactivate this new method in Workstation system control and see if it will activate and send the method parameters to your GC. If so, by now you should be presumably seeing the FID signal in Workstation.

Good luck! 4.5 is a very old version of Workstation. You should definitely consider upgrading if this is an option. Control of the 3800 GC was supported through at least version 6.9.2 of Workstation software.

[ariel.grostern]

Hi. Thanks for your reply.
The exact message is "Cannot find MINIMUM.MTH; cannot preset STARTUP1.MTH for module 3800"

I can control all of the oven/injector/detector parameters from within Star - the FID is lit, the System Control window shows the zone temperatures all at the correct settings....I can even see the signal in the display


however, nothing is being plotted in the Display - even though I can select what to display (e.g. Front detector status, or oven temp., etc).



I agree that a software update could be useful. .....

Ariel

[ariel.grostern]

One potential issue a lack of a module that may deal with Signals coming from the GC. Under Active Modules, only Module 3800.44 Control Method is listed, but the manual shows examples where a bunch of "Channel A" modules are listed.....

ariel

[Ultimate Science 101]

On this very old revision of software, it's hard to say whether the system requires a "module" to be specifically configured for processing/display of your detector signal. At least in the more recent versions of Workstation we've worked with, only the 3800 GC module should appear in the active/available modules window. There isn't a separate module for the GC detector.

You might try checking to see what modules are capable of being configured with workstation. In the newer versions of software, you right click on the top of the Workstation toolbar at the top of the screen and select "enable/disable" modules. If you can get to this feature, check to see what modules you have listed in both the enable and disable categories.