USB6008 DAQ temperature values

[Remmix]

Hi guys,

I started using LV recently. We have LV software lying around and need to use it to record and log analogue data from our plant. I bought a new USB6008 to test temperature acquisition. I have read some forums posted here in the past to find a clue but maybe i missed something. Here's what i have;

- AD594 amplifier (type K) which is powered by 9V bat

- LV 2009 software incl SignalExpress

-Type K thermocouple (which will measure approx. 0 - 60degC)

Firstly, I have configured my VI as attached below. I have some questions to do with the gain, sampling rate, voltage settings in DAQ Assistant, quantisation. I assume i wont need any linearisation as the temp range is small. Does my VI need to read voltage or thermocouple input settings in DAQ Ass.? I applied a gain of 247.3 as in the AD594 manual to convert the temp but measures about 500C at room temp. I then aplied polynomials but only achieve 2.3C at room temp. But with voltage range 0 - 5V aplied to DAQ Ass. i get around 25C in my room but when i dipped it in hot water i dont get any change in temp. What should i do?

Secondly what simple/inexpensive choice do i have on hardware to log data from about 90 temperature sensors. I sent an enquiry to NI in my region never got any response. 

Thanks for your help

RC

[Chris_Garratt_NIUK]

Hi Remmix,

The 6008 is not really ideal for thermocouple acquisition as it has a very low resolution. It may work (just about) with your application but is not a good solution. I would recommend a 9211 C-Series Module with signal conditioning which would allow you to ignore the amplifier and you would not need to configure it in DAQ Assistant. The USB TC01 is another option. The link I have posted below details the issues with using the USB 6008 for thermocouple data acquisition.

Thermocouple Measurements with the USB-6008 or USB-6009

If you need to discuss the best option for your project, I would recommend phoning NI UK (if your in the UK or your local branch). The UK number is 01635523545. If you have any other questions please reply to this.

Best Regards

Chris

[Chris_Garratt_NIUK]

Another useful Link:

http://zone.ni.com/devzone/cda/tut/p/id/4237

[Remmix]

Thanks by the way Chrisag for your help before.  I managed to use different hardware with some Yokogawa measurement equipment to do this.

Cheers