Chromatography Forum

Hi,

I'm having a little problem with my Agilent. When the GC is not being controlled remotely by chemstation the oven is fine but as soon as I go to load a sample (manual injection, controlled from chemstation) the oven turns itself off, so I don't think it's having problems maintaining temperature.

Additional info:
I've power cycled the GC and computer a couple of times to no success
Almost immediately prior to this happening, our He went and then we had problems maintaining inlet pressure, causing it to go into shutdown. A new cylinder and a couple of leak fixes later our pressure is stable but now the oven won't work!

Any help would be appreciated!

It must be something in your method. I haven't seen the chemstation for the 7890's but you need to make sure that your method is not shutting the oven off.

The bidirectional communication between GC and computer can be a problem. I usually set my method on the pc and if I make a change on the GC keypad, I always say "no" when it asks me if I want to change the method. If you turned off the oven from the keypad on the GC and saved the method, you may have created a situation where the method shuts the oven off.

There's an "Oven On" box in the Instrument Settings for the ChemStation Method that must be checked and the Method saved.

The keypad is locked when the computer is controlling the software so I'm not sure I could do that anyway? And the confusing thing was that it had been working for several days with that method previously. I'll have to double check but I'm pretty sure I didn't change anything that's why I'm confused!

I'm talking about the times when you want to get into the oven so you turn it off from the keypad. You're done with your work in the oven and you forget to turn it back on so you download the method and it asks you "do you want to save changes to the method". If you say yes, you've just put an "oven off" command in your method. That's the situation I'm talking about.

I think the later vresions of Chemstation E01 and up, save keypad entries without asking!

I think the later vresions of Chemstation E01 and up, save keypad entries without asking!

Overwriting an existing method without asking for confirmation would be ridiculous.

It is a little too easy to get the answer wrong when the software asks if you wish to save changes, at least when the operator is not attentive. I have never been happy with this scenario, but I suppose we should all just pay better attention.

I have one operator who routinely saves his methods with the gas flows off. Nothing we can do there but babysit and shrug when the system gets fried (it is good to be the bosses partner )