Dear all,
I have a USB module from Measurement Computing (USB 2408 2AO) and I use it for data acquisition. I control the module with a labview VI.
I use a K thermocouple and the analog inputs of the USB device to measure temperatures. The thermocouples are located very close where there are huge voltage spikes (ca. 700V spike). I put an RC filter with a zener diode to "kill" the spikes at the input of the USB module, and also a copper shielding around the thermocouple.
The temprature reading is performed without any problem with the software provided by Measurement Computing (Instacal).
The problem is that when I try to read the temperatures in Labview,the reading is very noisy and I cannot get any data from this noisy reading. At the same time I see the reading of Instacal and of Labview and they are not the same – I see in Labview the spikes that I do not see in Instacal. In Instacal the reading is constant despite to the voltage spikes, while in Labview it moves of 20 degrees!!!!
I used the same labview code without problems for reading other temperatures in zoneswhere there was no voltage spike….
I just want to get the same reading of Instacall in Labview but I do not get it done….
Does anybody know what I have to do?