analog I/O device connection to PC - question

[morty3]

Purchased an older model gas calibration device (still brand new in box after 15 years) and wanted to link to PC so I can log and chart the concentration levels.

Searched around a bit and found a few different freeware logging software choices, and decided on C-LOGGER by Contec since there seem to be a variety of USB and PCI supported devices, and seems to fit and is professional looking, etc..

Anyways, will attach pic what the old school terminals looks like from the back.

Wanted to double check with someone who understands electronics better than I do to see if the device I picked out will work?

The manual (from calibration device) states the following specs:

Output and Control Terminals
Analog Outputs:
The output signals are updated about 14 times per second.
The voltage output is an isolated voltage signal 0 to 10 V, proportional to the concentration (actually
this signal swings down to about -0.25 V below zero). Input resistance of the load should be higher
than 1 kW.
The current output is an isolated current signal 4 to 20 mA, proportional to concentration. Input
resistance of the load should be less than 650 W (optional 1350 W). The current output provides the
energy for the current loop. Attention: The current output must not be connected to an external power supply !

This is the device by Contec I was planning on using:
http://www.contec.com/product.php?id=355

And here is the data sheet for that:
http://www2.contec.co.jp/prod_data/adi128usbgy/adi128usbgy_e.pdf

Here's my question:  Will this device work for my needs?   I am confused by the input resistance numbers
"Input resistance of the load should be less than 650 W" and "Input resistance of the load should be higher
than 1 kW"  I checked with the manufacturer who is still in business but because I asked too many questions
about the device (they wanted to sell me a new one @ $5000) and they stopped answering. : )

The spec sheet for the Contec USB device states input impedance of put impedance of 1M OHM (Min.)

Maybe I should just try it and see but don't want to potentially damage the unit.

Voltage seems to match (plus or minus 10 volts) and looks like it can handle the current.

Thanks for anyone's input, greatly appreciated. 

Cheers, Morty

[amyk]

I've never seen resistance measured in watts... lol watt?

If they really mean ohms then 1M > 1k so you should be ok.

[bktemp]

I've never seen resistance measured in watts... lol watt?

I have seen this several times. This is a common problem with different character sets. If the charset is not displayed correctly the Omega character will be displayed as W.

If you see a resistance specification with W at the end, you can be sure it was Ohm originally.

[morty3]

Thanks amyk and bktemp!

Yes then that makes sense! Mystery solved! Yay!

Ok, one more quick question:

Would 12 bit be plenty for this purpose then?  There is also a 16 bit unit but the 12bit one I found seems to be in better shape.
In other words, would there be any noticeable difference given the signal is only updated 14 times a second?

If so then perhaps better to get the 16 bit unit?

Thanks! Morty

[morty3]

OK, I found this which seems to be relevant. Since my total range is 20MA total perhaps better to choose 16 bit unit for
potentially greater resolution.

http://labjack.com/support/faq/what-does-12-or-16-bit-resolution-mean

Does that make sense?

Thanks very much.. Morty