Answer Posted / 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
| Is This Answer Correct ? | 7 Yes | 0 No |
Post New Answer View All Answers
What are continuances of connecting earthing and shield of branch cables (instrument to Junction box), at the same earthing pot provided on JB? Is it ok, or may produce some problem?
What is the start up procedure of desalter
How to Calibrate Vortex Flow transmitter in field
Which are all the commonly used Bordon tubes in the pressure gauges. Do any one use ASTM A 312 tubes for this purpose?
in differential pressure transmitter,min&max pressure range for hp&lp
1- Explain about HPM 2- What is the FSC and explain the configuration of FSC 3- explain the complete loop of vibration, how it works (field to control room) 4- What is the use of proxymitter? 5- During job your partner effected with H2S then what you have to do. 6- what type of gland packing uses when valve glind is leaking.
How do you identify between actual alarm and false alarm in a Temperature Transmitter in SCADA based Control System
Which products are available in the Mass Systemswitch and System Manager AC range?
what is the minimum power (P=VI)to produce a spark?
Can any body help to get Rsemulator 5000 free from internet if possible then give me any link or any help .
what is orfics working in main steam line. is it increase pressure, velocity of steam flow and dicrease steam flow rate. or any other
What is critcal speed. what is resonant frequency. why we want to cross crtcal speed on higher RPM (early).
is motorized valve closed when power shutoff?
In my company plc based winders are operated. one day there was a data transmission failure alarm shown on pc. as per sir instruction we have reset master plc but winders were not triped and alarm gone. so what master plc do?
How to regulate the flow of Air in 4" line, with max flow of 330 nm3/hr and Pressure of 0.5 bar? please suggest the type of instrument required.