Interested to Buy Any Domain ? << Click Here >> for more details...
Explain " FAIL SAFE " feature in temp. measurement.
- 1 Answers
- 5326 Views
- Bapco Bahrain Petroleum Company, I also Faced
- E-Mail Answers
Answer Posted / carl_ellis
The fail-safe feature in temperature measurement uses some means to detect an open circuit in the sensor input wiring. An open circuit could be a broken wire, loose connection or a failed sensor.
Should an open circuit be detected, the output signal representing temperature will drive either full scale up usually to a value higher than 20.0mA or full scale down to a value lower than 4.0mA in order to flag, alarm or indicate a failed input circuit.
The failsafe feature and setup for upscale or downscale under fault conditions is sometimes referred to as "thermocouple break". In heating applications, upscale break is usually chosen because an indicated very high temperature on a controller's input will drive a controller's output down to 0% output (assuming reverse control action), preventing an overheat, fire or potential damage situation.
Some failures, such as a shorted thermocouple extension wire or sensor drift can not be detected in with open circuit detection.
Carl Ellis
Measure First
| Is This Answer Correct ? | 2 Yes | 0 No |
Post New Answer View All Answers
Which is your favourite subject & explain any one topic of it.
What are the types of control valves available
Dear Sir/Madam,im going to attend Hpcl written exams on feb 17th in instrumentation stream..can anyone send me the HPCL model papers and pattern of HPCL ....i ve not yet attended anything in HPCL...so i dont know how it comes...so just i need some model test papers and pattern ..pls help me friends...
What is modbus?
Hello to all....I am an Instrumentation Graduate and i am passed out in this year only.. I am unable to find the job in my core instrumentation.. so any boby tell me how to and where to search the job....please...and also tell me i there are any courses offered in the instrumentation stream so i can do it... you can send your suggestions to my mail-id i.e Ganesh20084u@gmail.com ... please..
There are two chlorination tonners both are connected to two pressure swithes and the pressure switch is connected to SOV which operates the valve to changeover the tonner selection i.e if pressure one tonner goes low the other tonner should come in line if it is inautomatic selection design a circuit using relays ?
Calculate the maximum pressure drop that can be allowed to occur across a control valve, so that we can prevent cavitation / flashing from occurring. Use the following formula: Δ P allow = Km (P1 – PvapourA) where, Δ P allow - the maximum allowable differential pressure for sizing purposes, or terminal pressure drop; Km- the valve recovery coefficient from the manufacturer’s catalogue; P1 - absolute inlet fluid pressure; PvapourA - absolute fluid vapour pressure at the inlet temperature; Use Atmospheric pressure = 101.3 kPa, P1 = 1200 kPa(g), PvapourA = 4 kPa, KM = 0.72
how to calibrate load cell
How to find out the current of two motors having same power consumption but different RPM?
Make a ladder diagram on LSL valve will close, on PSL valve will open and start the motor
all types instrumentation questions want
Can anybody tell me which type of question are asked in the interview for the FORMULATION(Pharma) as a instrumentation engineer, & question in building managment system.
What is the right procedure for adjusting the gap voltage of bently nevada vibration sensor?
What is the use of temprature compensation?
what is interface level measurement.who can calibrate interface level measurement transmitter online
