why we take 4 to 20 mA as out put of every instrument like
pressure transmittre ?why we cant take 0 to 20mA as output?
Answer Posted / vinoth s
If we use 0 to 20ma, then 0 will be the minimum value and 20
will be maximum value.. In case if there is any problem in
the transmitter or in the cables, we get the value 0 but we
think it as a minimum value..we cant able to know that
there is problem in transmitter.. In order to overcome these
constraints, we went for LIVE ZERO concept as 4ma.
0 ma will be consider as DEAD ZERO.
| Is This Answer Correct ? | 24 Yes | 0 No |
Post New Answer View All Answers
how many maximum enter 2mm Dia solid cylindrical pipe into 8mm Dia hollow cylindrical pipe. give answer with calculation.
why we are using drum level control valve air to close?
detail of mass flow meter pricipal
How the sizing of the analog signal cable is calculate?
What is the purpose of LO Overhead tank in turbines.
What is the basic difference between Modbus and CAN Open Protocols
how can leve transmetter calibate in feild .and also put cv and flow plz .....
what is the electrical operation procedure for switching on 27.6MVA electric furnace.
why Fahrenheit unit of moistur analyzer transmitter
how to commission furnace ( water heater)
what is a half wave, full wave, and bridge rectifer.
How ejector(or)evactor air pump is working in thermal power plant?
What is the purpose of bypass valve across AS valve.
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...
Describe the typical instrumentation used in monitoring the performance of a shell and tube heat exchanger.