Answer / carl_ellis

No, no, no.

A live zero is where the signal's value of zero engineering
units is an electrical signal value larger than zero.
For example, 4-20 mADC, 1-5 VDC, 10-50mV, etc., are all
examples of live zero. 4mA = 0 eng units. 1Vdc = 0 eng units.

On the other hand, a dead zero is where the signal's value
of zero engineering units is also zero electrical units.
0-20 mADC, 0-100 mV, 0-1Vdc, 0-5 Vdc, 0-5Aac are examples of
zero engineering units equaling zero electrical units.

0mA = 0 eng units; 0Vdc = 0 eng units

The value of a live zero is that zero electrical units
indicates a failed circuit; which could be lack of power, an
open circuit, a short circuit or failed signal source.

Neither live nor dead zero has an bearing on the linearity
or non-linearity of what the electrical signal represents.
Linearities are application specific.

Carl Ellis
Measure First

Answer / mugil

Dead zero: Dead Zero is below 4 ma.this is non linearity
Live Zero: Live Zero is 4ma.This is Linearity

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