thanks DET can do it but it sounds like its $5000+ and a ton of work. Not a simple as I was anticipating. I think I will just keep it for the FID and use it for FAME's or something.
here is there response:
Attached is a summary of the equipment we have for retrofit onto HP 5890 GC instruments. The hardware is compatible with installation onto a 5890 FID or NPD detector base. The NPD uses much lower flows of Hydrogen and Air than an FID, and these can be achieved with existing FID pneumatics controls by supplying low inlet pressures. The Hydrogen flow is the most critical, and some customers have substituted a Hydrogen flow controller with finer adjustment capability than the FID controller.
As indicated in the attachment, our hardware is not compatible with the 5890 detector electronics, so our retrofit requires a stand-alone Current Supply for powering the ion source, and a stand-alone electrometer for measuring detector signal. We recommend a Keithley electrometer which we can include or which can be purchased direct from Keithley at a slightly lower cost.
One consideration is that the output from the Keithley is an Analog voltage, so a data system must be capable of handling Analog inputs. One such data system is a PeakSimple system from SRI Instruments (
http://www.srigc.com) which is controlled by a laptop or desktop computer. An alternative is to acquire a 5890 Analog input board and cable to allow analog signals to be sent back into the 5890 and then outputted as if from an original 5890 detector. This alternative then allows the use of an HP Chemstation as the data system. (We have available a surplus Analog Input Board for $300, but not the matching input cable.)
Thanks for the inquiry. We have a retrofitted 5890 working in our facility and could possibly contribute additional comments on specific applications.
