Interested to Buy Any Domain ? << Click Here >> for more details...
Answer Posted / carl_ellis
@Marmkijani
The main reason for 4-20mA is that 2-wire field instruments need to use 3.5mA to power their own electronics in order to make a measurement and to control the regulated output.
4-20mA is also, as you pointed out, a range in which the energy in the circuit is low enough to qualify for Intrinsic Safety approval (when used installed properly with an approved DC power supply and I/S barrier).
The "live zero" is nice and convenient as a diagnostic for an open circuit fault, but it was not the main reason for 4-20mA; powering field instruments was the main reason.
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
how to relay switch sense the fault?
Square root calculation for dp flow transmitter?
what is exact time to study dcs and plc cources
Explain the working of rota meter.
plz send me general of ongc
kindly sent some demo question and answer
When doing a liquid seal on a differential flow transmitter , most of the time the sealing liquid will be heavier then the process fluid. For wich application will the sealing liquid be lighter than the process fluid if transmitter is mounted below the process line.
how to calculate range of level transmitter?
wich is coming the first HAZOP OR SIL
To become an Instrument DESIGN engineer, is there any softwares or training to become Instrument Design engineer, plz suggest me, Iam very much interested in designing.
Using your own examples solve a problem involving normal table. (experimental method and analysis)
What is wet leg condition and why is it used?
Type of level transmitter commnly used in Procees area are the following. a.________________This type of level transmitter works as follows
explain key exchanges in all security modes WPA,WPA2,TLS?
What you mean by multi stage control vavles?
