Answer / guest

A Cold Loop check is cold because it is done without
powering the loop.

A cold check consists of checking wire continuity from the
field instrument through junction boxes and through DCS/PLC
marshalling panel terminals to the control panel. Once
continuity has been confirmed, then a Hot Loop Check is
performed on the Loop's I/O.

A Hot loop check is 'hot' because it is done with the loop
powered up.

A Hot loop check consists of
- simulating a process input at the field instrument and
then checking the instrument's output and the response to
the process signal input at DCS/PLC.

- simulating outputs at the control end and checking for
correct response at the field end.

Carl Ellis
Measure First

Answer / vikaspanwar47

Hot loop check is power up checking .cold loop checking is continuity only. 

Answer / krishnan kumar sharma

Hot loop cheak on point stabilise the instrument in field and the cold loop cheak from the junction box to DCS /PLC .

how pressure transmitter work, what is its principal to measure and how its generate signal. for pressure transmitterinstallation which precautions must be taken ??

0 Answers  

---

what is meant by orderm of a system. will the stability of a system increases by incresing order of a system

1 Answers  

---

IF TX SHOWS SLOW RESPONSE, WHILE A CLOSE LOOP AND WHEN WE PUT THE CONTROLLER ON MANUAL THE PROBLEM RECTIFIED, SO WE CAN SAY THE PROBLEM IS IN

1 Answers   IFFCO,

---

Why Bently Nevada use negative voltage for vibration probes?

4 Answers  

---

what is the procedure of belt scale calibration?

0 Answers  

---

---

any questions on motor and energy conversions machines?

0 Answers   ABB,

---

we callculat main steam flow by D.P. but where is H.P. & L.P. IN Orfics?

3 Answers  

---

How do you troubleshoot accelerometers used in Vibration monitoring/tripping

1 Answers   Air Liquide,

---

what is the formula for calculating milliampere at different pressure points for eg 4-20 ma = 3-15 psi but if i have to check the ma at 4.6 ma?

4 Answers  

---

what is function of DCS , and how is it work , explain with difination

1 Answers   Bapco Bahrain Petroleum Company,

---

anybody having Qatar Petroleum questions for instrument Technician offshore ....please send me

0 Answers  

---

Can any one tell me what type of question asked for instrumentation and control interview panel??? pls mail ramashankar.goel@gmail.com

0 Answers  

---