Why we are measuring 4-20ma? Why we are not taking 0-20ma? Plz answer this
Answer / mariyappan
Because of dead zero and live zero concept.
Dead Zero: this is basically derived from ohm's law
V=IxR. In electronics circuit minimum 250 ohm resistance is using. so V=Ix 250. Substitute I=0,1,2,3,4 after substitute 0 u will get V=0 ohm,(1;V=250 ohm,2;V=500 ohm,3;V=750 ohm,4;4=1000 ohm or 1 V) so when 4 ma is coming u will get 1 V,8 ma=2v,12 ma=3 V,16 ma=4v,etc..... u will get linearity .thats why 4 ma is choosing in all analogue value.
Live Zero: if tx is failure that time also zero value is coming.thats why 0 is not choosing
Is This Answer Correct ? | 10 Yes | 0 No |
can anyone can let me know in Eurotron Micro cal 2+ calibrator in milli amps source mode we are not able to get 20 milli amps output it only produces 1.52 milli amps out, but display shows increase in milli amps , and err6 displays, let me know how to remove the err 6.
What is meant by GAP VOLTAGE, in vibration measurement. Normally how much GAP VOLTAGE is set and state the reason.
explain Cascade Control strategy with the help of a block diagram. also exlain its working in a distillation column
Anybody can tell me how to convert mmHg2o /psi to scfm please give me formula of conversion
what is thermocouple output
How to calibration a control valve?
Convert a pressure, level, flow, or temperature process variable value into the appropriate pneumatic or electrical value given different types of instruments.
6 Answers Jindal, MCL, Thermax,
What is the difference between fiber optic cable & Ethernet cable
2 Answers BEMCO, CCC, Pidilite,
WHAT IS D/O D/I AND A/O A/I PLZ EXPLAIN
Basics Instrumentation Question
1 Answers Advantek Fuel Systems,
i am working in the automation company...i want to just know how actully pid control valves are tune????...
If the vibration probe near to the shaft,then output voltage will be decreased r increased?How?