5890 Electronic Pressure Control & Flow Measurement question

[5890Hacker]

Hi

I'm another one of those guys trying to get an old hP 5890 from ebay up and running.

The device has 1 FID and 2 Split/Splitless Inlets (one for a capillary column, the other seems to be for a packed column).

The Split/Splitless inlets are set up with electronic pressure control on the split vents.

There are two manual flow control knobs controlling flow to the inlets (Total Flow knobs).

The two electronic flow transmitters (A and B) are not plumbed into the flow path and are unused but they seem to work.

Here are my two questions:

1. Is it common for you to not use the electronic flow transmitters when electronic pressure control is used (maybe because the measured flow would never match the calculated flow from the pressure module?)?

2. Do you guys see anything wrong with plumbing the electronic flow transmitter right after the total flow knob (total flow to inlet) and using the measured flow in conjunction with the electronic pressure control to control the split ratio?

Thanks!

[AICMM]

5890Hacker,

I have bought numerous 5890's with Electronic flow sensing and all of them were disconnected. If you had a TCD it might be a good idea because a loss of flow could wipe out the TCD but since you have an FID it is probably not necessary. Also, they do NO flow control (seem you already know this) AND you need to calibrate them to get any useful information out of them which means you need a flowmeter..

Since it is EPC equipped I don't think you will find them much help.

Best regards,

[5890Hacker]

Thank you for the post. I'm glad to hear I can put the side cover back on and avoid re-plumbing anything.

I appreciate the info.