I am using a PCI-6024E DAQ card for thermocouple(TC) measurement. The
TC is installed in the mold cavity of an injection molding (IM)
machine. The leads from the TC are connected to the DAQ card using a
CB-68LP board. I made a temperature mesurment task in LabView 7.0
with the two leads from TC as differential inputs and used CJC value of
25 deg C.
The problem is that when the IM machine is OFF, I get a reasonable temp
reading with some slight noise but as soon as I turn ON the IM machine,
the temp readings go wild with a lot of variations around the mean
value. The temp values also don't go to higher values when the TC is in
contact with the molten plastic in the IM machine.
Do I need to ground something here or put a resistor in the I/O board?
BTW the IM machine is grounded and the TC give correct temp values when
connected to a hand-held temp reader.
Any help will be highly appreciated.
