Answer / 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

How much voltage we are using at switches?

4 Answers   Edac,

---

what can of fault ofently come in vibration mesurement?

0 Answers  

---

If a differential pressure transmitter is calibrated for 0~2500 mmH2o and transmits a 4~20mA dc signal. The transmitter is placed across an orifice plate which is sized to create 2500 mmH2o differential at 5000m3/Hr a) what is the flow rate when the transmitter signal is 13.0mA DC? b) what is the signal output of the transmitter when flow rate is 2500 m3/Hr ?

5 Answers  

---

what is coriolis principle for mass flowmeter?

5 Answers   ABB,

---

what is mean by live zero and dead zero

3 Answers  

---

---

What is the different between ESD & PLC.

1 Answers  

---

What is BMS (Building Managment System)& is AHU / HVAC are in BMS.

12 Answers   Alghanim,

---

how can leve transmetter calibate in feild .and also put cv and flow plz .....

0 Answers   IBM,

---

What is the diffrence between ff tx and non ff tx

0 Answers   Jindal, Rosemount,

---

how to calculate density?

2 Answers  

---

what is preventive maintenance , explain with difination

1 Answers   Bapco Bahrain Petroleum Company,

---

the pump holds on run indication into the dcs and filed local control panel remote push button condition operaton wrong like when the push button pushing conditions the pump is off and the push button release condition the pump is on totally opposite condition . And control room inside give the stop command into dcs just 1secon relay engage and again normal condition. How can I slove

0 Answers  

---