geirove
2008-06-13 11:40:07 UTC
Hello,
I am trying to find out the Maximum length a cable connected to e.g. a Thermistor using 4 wire connections may have.
My hardware will be a PXI box running RTOS (VxWorks). I have found a DAQ card called PXI-4351 (<a href="http://sine.ni.com/nips/cds/view/p/lang/en/nid/1494" target="_blank"> http://sine.ni.com/nips/cds/view/p/lang/en/nid/1494</a> ) but I am not sure if it is old, since I cannot find it listed under DAQ devices on the PXI pages (!). I may also need the TBX-68T terminal block.
The distance between the PXI Box and the Thermistor will be approx 100 meter (300 feet). I will use a shielded cable and 4 wire connections. I have searched all over the inernet for 2 days, but am unable to find if this measurment can be done over 100 meter (300 feet) cables without using an amplifier at the sensor end. I will require about 0.5 degrees accuracy, but will the Noise Levels be acceptable when using the filtering capabilities of the board. Sample rate is low: Only approx 1 sample a minute.
I appreciate all the help I can get !
I am trying to find out the Maximum length a cable connected to e.g. a Thermistor using 4 wire connections may have.
My hardware will be a PXI box running RTOS (VxWorks). I have found a DAQ card called PXI-4351 (<a href="http://sine.ni.com/nips/cds/view/p/lang/en/nid/1494" target="_blank"> http://sine.ni.com/nips/cds/view/p/lang/en/nid/1494</a> ) but I am not sure if it is old, since I cannot find it listed under DAQ devices on the PXI pages (!). I may also need the TBX-68T terminal block.
The distance between the PXI Box and the Thermistor will be approx 100 meter (300 feet). I will use a shielded cable and 4 wire connections. I have searched all over the inernet for 2 days, but am unable to find if this measurment can be done over 100 meter (300 feet) cables without using an amplifier at the sensor end. I will require about 0.5 degrees accuracy, but will the Noise Levels be acceptable when using the filtering capabilities of the board. Sample rate is low: Only approx 1 sample a minute.
I appreciate all the help I can get !