Why we use 4 to 20 mA, (This is International Standard)
instaed of this can we use 4-16, or 4-24 or 3- 15 or any
other range
Answer Posted / richard marks
the 4mA zero is termed a "live zero". If 0mA was the zero
point there would be no way of telling if the transducer
was reading zero or in a fault condition eg. an open loop.
with a 4mA zero an open loop would drive the indicator eg.
a recorder into a minus figure (-25%). The 4 - 20mA scale
is to give a calibration points for 0-25-50-75-100%.
Because the start point is 4 the steps are 4mA.
| Is This Answer Correct ? | 14 Yes | 6 No |
Post New Answer View All Answers
What is 1:1 redundancy ?
flow transmeter accuracy 0.075% of full scale & find ucertainty is 0.025 % so what is maximum limit band of uncertainty
What is intrinsic safety mean.
what does it mean an active front end in vfd plz explain it briefly
hello sir/madam, I,Subramanian need 5yrs placement papers of officer trainee of Instrumentation technology.pls send to this mail id mani_nxtgen@yahoo.co.in please do the needful. with regards, subramanian.v
what are the definitions of input, output, command & signal according to instruments controlled by PLC using DCS System?
how to rectify the poor signal strength in utrasonic digtial flow meter ,model:ge digital xce868i
In turbine what does term CDP, NI, NH, HSSOC means.
I am manjunath having exp in maintenance of chemical plants,know i want to do a design course INTOOLS,after doing design course can we get jobs in design field.sinve i dont have design exp..
How to Calibrate Temperature Switch in field
How the sizing of the analog signal cable is calculate?
principle of automatic votage regulator
What is Positive Calibration and Negative Calibration?
What are different types of valves?
What is the right procedure for adjusting the gap voltage of bently nevada vibration sensor?