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Detector output to computer..?

Posted: Fri Sep 25, 2009 4:30 pm
by pipettemonkey
I have a PE 235, HP 1050, and HP 1100 detectors. Currently, I collect my data via strip chart recorder. I'd like to send detector output to a PC software program instead. All I really want is to have electronic chromatogram files with integration, retention time. What is the most cost efficient way to do this?

Do I need one of these? What can I expect to pay?

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Posted: Fri Sep 25, 2009 8:00 pm
by ScottHorn
I suggest you look at the "PeakSimple" system by SRI. They offer a few models that differ in the number of input channels. Some also have digital output for basic control of pumps and other equipment. The software is free, and we use it on a regular basis for analytical size exclusion with proteins. It offers integration as well.
Another option is the Clarity chromatography data station. This package will probably be a bit more expensive, but it allows control of almost any instrument, it can take signals from practically any detector, and has a very easy to use integration package. I believe "Clarity Lite" offers data acquisition without instrument control. You'd need to buy one of their analog/digital converters to get the signal into your PC.
Also check out the "LabJack". I don't remember the manufacturer, but it is a very "open" instrument control module and analog/digital converter. You'd probably have to write your own software though.

choose software first, then hardware

Posted: Sat Sep 26, 2009 1:26 pm
by Jeffrey Bodycomb
What is the most cost efficient way to do this?
First, what do you mean by "cost efficient?" There is a definite trade off between required effort and required cash. You should determine in advance what is important to you.

You may find yourself evaluating the entire package before purchasing either part.

The most difficult part of this will be the software. Scott Horn has already discussed some options.

Once you select software (maybe based on price) then choose the hardware. Typically, a software package will only work with certain data acquisition hardware, even though it may accept and analyze signals from any detector.

Let me try to explain the statement above while ignoring some subtleties irrelevant to that point. Most detectors will provide an analog output (say from 0 to 1 volt) that can be converted into numbers by any (appropriate) data acquisition hardware. But, different data acquisition boards (or boxes) communicate with the computer in very different ways. The most obvious example is that some boards connect to the computer via USB and some connect to the computer bus (e.g., PCI). For GPC users, the differences between the two are not of much practical importance. But, the software has to know where to find the device and how to talk to it. And there is no "universal" approach. So, even though a software package will work with most detectors, it will only work with certain data acquisition boards.

If you choose SRI's software then you must use their hardware and you cannot use Brookhaven's hardware. If you choose Brookhaven's software then you cannot use SRI hardware.

Disclosure: My employer, Brookhaven Instruments offers software and instruments for SEC/GPC http://www.bic.com/ParSEC.html. When pressed I will either a) try to sell you an instrument or b) ramble on in geek mode.

Posted: Thu Oct 01, 2009 2:45 pm
by pipettemonkey
I have found a PE 600 series interface on an online aution. Any idea if I will be able to use ANY non-PE software (i.e., affordable/free programs) with it?

Posted: Thu Oct 01, 2009 2:50 pm
by tom jupille
probably not :cry: Even if PE gave the details and provided a driver, finding a piece of non-PE software that talks to the device would be a very long shot.

Posted: Thu Oct 01, 2009 9:08 pm
by pipettemonkey
In general, if I purchase a used or otherwise auction-bought interface/software package, will I still have to purchase a license?

Posted: Sat Oct 03, 2009 7:09 pm
by ScottHorn
Whether or not you need a license depends on the software package. With some you can just install it and go. Others require a "hardware key", which is usually a usb dongle that must be present before the software will run (make sure it's included if the software requires it and you're buying used). Other have even more complex ways of guarding against piracy. If you're looking to acquire a signal from just one detector, SRI's peaksimple package is $1500 for the interface box, and the software is free. There are plenty of cheaper signal acquisition modules out there, but they often require a lot of setup and tweaking if they're not designed for the type of chromatography you're doing, or chromatography in general. I've even seen sound cards used as signal acquisition devices, high end models can acquire a signal at 44khz or more, which is more than adequate for most chromatography applications. I use the SRI package for signal acquisition in low pressure liquid chromatography for its simplicity. I inject my sample, and click the start button of the software, and it displays the chromatogram as the run progresses. For more complex prep scale affinity procedures I use Clarity with the INT7 pci module. I write a method, put my inlet tube in my sample (usually around 1L), and hit start. The next morning when I come in my product is in one beaker, my waste in another, my material for reprocessing in another, and the chromatogram, with signals from the UV and pH detectors, is printed or emailed to me, all without any human intervention. Of course, that package costs a bit more than the SRI package.