Answer Posted / gireesh gokuldas
1)Obtain Permit to work. Confirm proper isolation of process.
2)Depressurize the system by draining or venting.
3)Disconnect the process tubing and replace with correct fittings for calibration with pressure source.
4)Wear goggles to avoid splashing of liquid into eyes when depressurizing.
5)Use a Digital Multimeter (DMM) set to the continuity range to check and verify that the switch contacts are as indicated: NO (Normally open) and NC (Normally close).
6)Connect the DMM between the normally open contacts (NO) and the common terminal (C) of the switch. The meter should read "open circuit"
7)Adjust the hand pressure regulator to increase the pressure to the set point of the pressure switch until the contacts change over.
8)The meter should now read "short circuit". Note the pressure reading and write it down. This pressure is the switch set point for a "rising" pressure.
9)Increase the pressure to the switch to its maximum rating.
10)Slowly reduce the pressure to the switch until the switch changes over from closed to normally open again.
11)Note and write down this pressure reading. This pressure is the switch setting for a "falling" pressure.
12)From the readings you have taken work out the pressure difference between the rising and falling pressure settings. This is called the "dead-band" of the switch.
13)The dead-band calculated should be equal to or less than the manufacturers’ dead-band
14)Disconnect the calibrator and restore the process tubing and put the switch in service.
15)Complete the calibration form and apply the appropriate calibration label.
16)Clean the area and clear Permit to work.
| Is This Answer Correct ? | 16 Yes | 3 No |
Post New Answer View All Answers
How to calibrate the flow transmitter
how to calibrate mass flow meter (Coriolis)? Example calibration range: 0 to 2500 kg/hr line size 3" fluid: Etheline glycol (MEG)
how to convert MA in to measuring values..and how mwasuring values into MA ?..plz ansr.i have intervw
the whole paper was based on Transducers..questions like define repeatability, error,accuracy,precision..den there were many q. on the conversion of Pa to mmHg and other units.. also..der wer few Q. on some level sensors(with diagram)
What is loop1 and loop2 in MTS LT?
Im having problems with interfase betwen SPI v7.0 and SPPID v5.05. Previous versions of Intools shoul be fixed with SPPIDproj.ocx file. It was necessary to replace this file with one that allows the connection between different versions of SPPID. It is necessary in the current version to do the same?Thanks
What are the materials available to prepare individually for competetive exams in Instrumentation field? Plz reply...
detail of mass flow meter pricipal
Which type of diagphram use in costic line,DM water line,natural gas line,oil line?
what is the electrical operation procedure for switching on 27.6MVA electric furnace.
Explain the difference between plc and cnc?
WHY THE DEGREE OF VALVE PLUG AND VALVE SEAT IS SLIGTLY DIFFERENT I CONTROL VALVE TRIM DESIGN
how to calibrate corollaries (Mass flow meter)?
what is different between 2,3&4 wire rtd and how much maximum distance using plc to field.
what is o2 analyzer and how it measured ,what is the role of this analyzer in cfbc boiler...