Why most of analog o/p devices having o/p range 4 to 20 mA and
not 0 to 20 mA ?
Answers were Sorted based on User's Feedback
Answer / ekailash
4-20 mA is a standard range used to indicate measured
values for any process. The reason that 4ma is chosen
instead of 0 mA is for fail safe operation.
For exa.- a pressure instrument gives output 4mA to
indicate 0 psi, up to 20 mA to indicate 100 psi, or full
scale. Due to any problem in instrument i.e. broken wire,
its output reducess to 0 mA. So if range is 0-20 mA then we
can differentiate whether it is due to broken wire or due
to 0 psi.
Is This Answer Correct ? | 9 Yes | 0 No |
Thank u Mr.EKailash .I think it is required answer.
Is This Answer Correct ? | 0 Yes | 0 No |
What is the lifetime of a Thyristor? Is there a recommended lifetime for thyristors after which they should be replaced?
what is the principle of switch gear? where its function ?
what is potentiometer & rheostat
why impedance relay is used for medium transmission line protection
What is working principle of washing machine?
what is voltage
what is the difference between Ith & Iu rating in MCCB. Particularly on SACE ABB Circuit Breaker?
what do u mean by knee point voltage?
difference between ordinary MCCB & Motorised MCCB
what is phase to phase to phase to ground fault
what is the difference between the electrical and electronic choke?
when the supply of MSEB is cut off & all the load of the industry is driven on generator at that time the capacitor which is connected in industry for power factor control is switched off why?