11-04-2008 06:03 PM
Hi,
I am trying to collect some RTD data into labview with a USB 6210. I've wired the RTD per the "Temperature Measurements with RTDs: How-To Guide" located here http://zone.ni.com/devzone/cda/tut/p/id/7115. I have used an external power source of 5 mA. I then tried to setup the data collection in the VI with the DAQ Assistant. The settins have the following values:
Signal Input Range
Max = 100
Min = 0
Scaled Units = deg C
RTD Type = Pt 3851
Ro = 100
Configuration = 3-Wire
Iex Source = External
Iex Value (A) = 5m
The RTD is an RTD-810 from Omega Engineering, and according to their tech support this RTD qualifies as a "PT 3851 because it fits the european curve for RTD Temperature vs. Resistance.
When I click Run in the DAQ assistant to see some sample values, they are way off. The DAQ assistant returns a value of a steady 318, while the RTD is sitting in the ambient air at about 20 C. I also submerged the RTD in an ice bath and there was no change in the reading...
Any thoughts on what I am doing wrong? thanks!!!
11-05-2008 05:36 AM
Hi DAQ Newbie,
I would suggest that you first of all check that you get variation from the device by looking at the analog channels in Measurement & Automation Explorer and open up a test panel. Here is a link to a detailed explanation of how to do this. What sort of variation are you expecting from the device? Have you verified that the device is changing in voltage by simply putting a Digital Multimeter to it?
Have you double checked both the wiring into the DAQ device and that you are using the DAQ Assistant to look at the correct channel?
Hope this helps,