why 4 to 20 ma ,why not 0 to 20 or 3 to 15 or anything
Answers were Sorted based on User's Feedback
Answer / pradip
*To determine live zero
*To avoid noise
*Linearity is maximum
*Transmission of signal over long distace
Is This Answer Correct ? | 1 Yes | 2 No |
Answer / kambiz
why 4ma show higher zero ?
i have transmiter flow renge 0-1000 m3/h but 4 ma show in
monitoring 200 m3/h and 20 ma show 1000 m3/h i want when 4ma
show 0 m3/h and 20ma 1000m3/h
Is This Answer Correct ? | 1 Yes | 2 No |
Answer / smruti senapati
with 0-20 ma you canot distinguish between minimum field
value and connection break.with 2-20 ma ,internal circuits
can distunguish between connection break of minimum
value.normally when the value is minimum the transmitter
will give you 4 ma while in case of connection breakage it
will give 0 ma...
Is This Answer Correct ? | 1 Yes | 2 No |
Answer / rajesh
As per Numerology 4 is the good number for all analog instruments. next number of 4 is 5. multiply both of them
(4 x 5 = 20).
So only 4 to 20 MA is used in all Analog Signals.
Note: Sorry Friends, i just check whether this website accept all answers or filter.
Don't accept these answers even more no of YES. Because everyone will answer this website without knowing the answer.
Is This Answer Correct ? | 0 Yes | 3 No |
Answer / palak m
Why only 4 mA, why not 1,2,3 mA? Because it is universally
tested and approved that at 4 mA the signal has minimal
interference.
Is This Answer Correct ? | 9 Yes | 19 No |
Answer / bill
4 milliamp is used as span lower limit, because some
elements on the loop require power from the loop and
therefore a minimum level of power must be available
Is This Answer Correct ? | 11 Yes | 35 No |
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