why we are using ungrounded RTD sensor and what is difference
between grounded RTD and Ungrounded?

Answer Posted / carl_ellis

Show me a 'grounded RTD'. I have never seen a commercial
grounded RTD. The probability of a measurement error due to a
ground loop is too high.

An RTD measurement requires a stable, constant current
source, which is generated by the sensing circuit. If an RTD
element were grounded, a ground loop could affect the current
source depending on the difference in ground potentials at the
RTD element and the sensing circuit. That would create an error
in the measurement.

Grounded thermocouples work some of the time, but other
times some form of isolation is needed because of a ground loop
issue with a thermocouple.

You use ungrounded RTDs because that's the best way for them
to function.

Carl Ellis
Measure First

Is This Answer Correct ?    4 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

can anyone can let me know in Eurotron Micro cal 2+ calibrator in milli amps source mode we are not able to get 20 milli amps output it only produces 1.52 milli amps out, but display shows increase in milli amps , and err6 displays, let me know how to remove the err 6.

1753


How to convert milliampares into flow??

1275


Which Signal hart communicator work? If there any signal change when hart connect while transmitter in line ?

930


how to calibrate electro pneumatic positioner 8013 mil controls ltd ?gsr

7451


which type inter lock use in petrochemical refinery,and oil & gas?

2631






what is isloted barrier how it works and what are the main purpose.how it make safe area.

1594


principle of dead weight tester ?

1600


In my company plc based winders are operated. one day there was a data transmission failure alarm shown on pc. as per sir instruction we have reset master plc but winders were not triped and alarm gone. so what master plc do?

1406


hello friends, can you please send me the model paper or question paper to be prepared for hpcl examinations????????? You can mail me at rahim_here@yahoo.com waiting for your reply........... help me .. plz.....

2146


Explain working principle of lvdt?

632


Instrument QA/Qc what is the project quality plan?conduit inspection RFI. which documents attache with package?

10400


Hi, Is there any smart plant instrumentation design training institute in Bangalore?

1200


What are continuances of connecting earthing and shield of branch cables (instrument to Junction box), at the same earthing pot provided on JB? Is it ok, or may produce some problem? 

2014


Why trim span ? How?

1080


What is the difference between PLC and DDC?

1672