WHY WE NOT USE 2-20mA,1-20mA,3-20mA or 10-50mA SIGNAL? INSTEAD OF 4-20mA.

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WHY WE NOT USE 2-20mA,1-20mA,3-20mA or 10-50mA SIGNAL?
INSTEAD OF 4-20mA.

Question Posted / s.senthil

6 Answers
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WHY WE NOT USE 2-20mA,1-20mA,3-20mA or 10-50mA SIGNAL? INSTEAD OF 4-20mA...

Answer / ali abideen ,,

Generally in a transistor some amount of voltage is
required for turning it on. This voltage is the cut in
voltage. Up to this voltage the exists a nonlinearity in
its characteristics. Beyond this cut in voltage the char.
of transistor is linear. This nonlinear region lays between
0-4ma, beyond 4ma it linear. This is why 4-20 ma range is
used.

Is This Answer Correct ?

29 Yes

13 No

WHY WE NOT USE 2-20mA,1-20mA,3-20mA or 10-50mA SIGNAL? INSTEAD OF 4-20mA...

Answer / anil

starting with 4ma is to know DEAD or LIVE of the
transmitter,4 to 20 is used for linearty and according to
ohms law to covert 1 to 5 volt dc,

Is This Answer Correct ?

19 Yes

4 No

WHY WE NOT USE 2-20mA,1-20mA,3-20mA or 10-50mA SIGNAL? INSTEAD OF 4-20mA...

Answer / ravi vaya

Because 4 mA is called live zero of transmeter
If we set 0 mA at 0 pressure ya any ,we can`t deside inst.
is working ok .

And also mA is be a linear from 4 mA

Is This Answer Correct ?

3 Yes

1 No

WHY WE NOT USE 2-20mA,1-20mA,3-20mA or 10-50mA SIGNAL? INSTEAD OF 4-20mA...

Answer / lalatendu keshari prusty

4-20ma signals will travel along distance without dropping signal value and the internal circuit distinguish between connection break & minimum value.

Is This Answer Correct ?

0 Yes

1 No

WHY WE NOT USE 2-20mA,1-20mA,3-20mA or 10-50mA SIGNAL? INSTEAD OF 4-20mA...

Answer / mike betts

I am not sure why the range of 16mA i.e 20 - 4, but the 4mA
starting is so that you have a posative value of current for
all values that the loop current represents. This way, if
you have no current at all, the loop is open circuit for
some reason.

Is This Answer Correct ?

4 Yes

9 No

WHY WE NOT USE 2-20mA,1-20mA,3-20mA or 10-50mA SIGNAL? INSTEAD OF 4-20mA...

Answer / vanapalli rajesh

because 4-20ma is a linear range compared to other ranges

Is This Answer Correct ?

8 Yes

22 No

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