Answer / sam

This procedure can be used to calibrate any type of
instrument in the field on a live plant regardless of it's
type or application. The only variation in the procedure is
what test equipment you will use to calibrate the instrument
with. For instance calibrating a temperature transmitter you
want to take a HART and decade box with you. Calibrating a
pressure , flow or DP transmitter, you want to take a HART
and pressure pump with you like a Druck or hand pump with a
precision gauge on.
The procedure:
Since the transmitter is on line and on a running plant, you
need to determine a couple of things first before you start
working on it. First and most important of all, what does it
do? Is it a control transmitter, a trip transmitter or just
a indication.
Control transmitter means it's output will go to the DCS and
is linked to a PID controller which will give a continues
output, based on this input, to a control element in the
plant plant like a control valve or a heater element. These
are all critical control components that will trip the plant
if you upset their stability.
Trip transmitter means that it is linked to the ESD system
and will start a plant shut down if it is seeing a to high
or low pressure, flow, DP or level depending on the
application you are working on. Just indication means that
it is completely safe to work on and you cannot trip anything.
To make the control transmitter safe to work on you need to
put the DCS PID controller in manual. This will keep the
output of the controller at the current output position and
bypass the output function of the controller. In a fast
moving application the control room operator will send a
field operator with you to control the control valve
manually with it's hand wheel while you work on the control
transmitter.
To make the trip transmitter safe to work on you need to put
a inhibit in the ESD system output trip function of the
transmitter. This is also sometimes refer to as a MOS
(maintenance override switch).
In both cases the control room operators will do this for
you providing that you have all the permit to work and
inhibit permission paperwork in place.
Good luck

Answer / guest

throgh HART communicator it is possible to calibrate online

Answer / abi

Using Pressure calibrator (Fluke or Druck)and HART
communicator we can calibrate any pressure transmitter on line

Answer / abdelkader

the first you must see is the transmetter is used as the
loop or indication , if is used as the loop , must avert
operator to put it im manual loop , and if is other case ,
we can calibrate easy without alter the system .Used PID to
determine transmetter function .

Answer / rohit pareek

if we have a master transmitter we can connect parrelal
to each other . when master transmitter will show the
pressure,the pt must indicate pressure with aqual to master
transmitter

How will you select suitable Instrument for Process line/Tank/Vessel?

5 Answers  

What is the difference between floating and fixed voltage?

1 Answers  

what is a instrumentation ?

10 Answers  

How ejector(or)evactor air pump is working in thermal power plant?

0 Answers  

A differential transmitter is calibrated to measure the flow of lquied, explain what wil happen if the fluid is not pure but contains some bubble?

2 Answers  

in split range control valve,two valve should be in two different line and that should have some distance,and we have only one positioner feed back link.so how we connect one feed back in two control valves?if you have picture please forward me.my email id kb.syamkumar@gmail.com

2 Answers  

what is the difference between profibus and controlnet networking.

0 Answers   HZL,

In turbine what does term CDP, NI, NH, HSSOC means.

0 Answers   ADMA OPCO,

Hello-I know this not an engineering question,I am working in gulf & i want to do correspondence diploma in instrumentation,can any one give me the address of any university in which this courses are available.

2 Answers  

What is difference between “Fault Tolerant” & “Fault avoidance” PLC? Application where these system s are used?

0 Answers  

what is cascade system ?

1 Answers   RSP, Thermax,

1. what is 3 point calibration & 5 point calibration? 2. If we use hart communicator to set the LRV & URV of a smart transmitter, did we calibrate the transmitter? why? 3. Make a complet list if meterials needed to properly connect a pressure gauge to a steam pipe using 1/2 inch stainless steel tubing. The gauge connections is 1/2 inch NPT-M and the steam pipe tap has a 1/2 inch female coupling, compression fittings are use. 4. What are the tools in loop checking? 5. What would the ISA symbol of a square root extractor look like? 6. What would you do to completely prepare for the configuration? 7. What safety measures must you undertake when doing configuration? 8. what are the two most commonly use programming languages used when we configure a PLC? 9. What would you do if you accidentally skipped a step in the configuration procedure? 10. How would you know if the configuration were sucessful? 11. Name at least 3 selections available when we configure the burnout protection of a controller?

3 Answers   EI Electrotechnical Institute,