why 4 to 20 ma ,why not 0 to 20 or 3 to 15 or anything

Answer Posted / ibrahim s

4-20mA :-
* Easy to find the open circuit(because this
signal level starts from 4mA, if the circuit in open the
output shows 0mA, so we can find easily the open circuit).

* Easy 0 to 100% segregation
4mA - 0%
8mA - 25% 12mA - 50%
16mA - 75% 20mA - 100%

* All manufacturer following the same standard.

0-20mA :-
* If it starts form 0mA, not able to find open
circuit easily.

3-15mA :-
* Less linearity, because 3mA is 0%, 15mA is 100%
so the deviation b/w 3-15mA is lesser than 4-20mA, So that
it reduces the accuracy of the measurement.



So that 4-20mA is preferred over 0-10v

Is This Answer Correct ?    122 Yes 5 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Why humidity limit is 30 to 55 % for raw material storage?

3608


any body who gone thru recent iocl interview.INSTRUMENTATION questions. I need.

1938


we are using centum vp as monitoring with Dell precision work station T3600 but some times PC(s) are restarted automatically . how we can solve this problem? thanks

1754


Why plc require in analog input 4-20amp & 0-10 volt?

623


Why rdt and thermocouple both give different output .and one things more, how to generate  ohm or mili volt  plz mail me merajalam143545@yahoo.com

2314






How RAL(Rotary air lock)works in cement industry?

1955


How signals can be taken through modbus?

678


In turbine what does term CDP, NH, HSSOC means.

1332


Isometric drawings are generated during _________________ phase of a project

1615


In power plant to measure vibration of a turbine we install sensors. Before install this sensor we have to set gap voltage. What is meant by gap voltage and its use?

1613


what is KV and XV valve

1290


I am having a Phoenix digital to modbus converter. The o/p of the same is connected to flow computer FB407. But the digital signals are updated only after one minute in the flow computer. what may be the cause of delay in communication? Flow computer is having a scanning period of less than 1 sec.

1463


Difference between ultra sonic flow meter

1547


Give Detail information about plc,dcs,and scada system?

1264


Can any body help to get Rsemulator 5000 free from internet if possible then give me any link or any help .

2067