Answer Posted / simon marshall
The 4-20mA loop can be used with active sensors. The
minimum current of 4 mA powers the sensor. (The sensor then
must act as a variable current sink through its supply
terminals varying the current it draws in proportion to the
quantity it is sensing such as the millivolts or so from a
thermocouple, for a 4-20mA temperature gauge.) I do not
know how the powering current of 4mA was arrived at. The
specifications allow a range of maximum voltages for the
loop to operate on and the sensor power can then be
satisfied in different designs by altering the minimum
voltgage drop on the device. The item powering the loop
then must also be designed to measure the current drawn in
the loop but read out on a display with the transfer
funtion zero to full scale deflection = 4mA to 20mA
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
What is a cathode ray oscilloscope (cro)?
Explain the difference allen bradley and siemens plc
What is meant by natural commutation?
In C language the condition(4%2==0) and in scanf statement the declaration as %d for integer.Now in the first condition it performs the modulo operator but why it is not so in scanf statement?
What is the effect of temperature on the reverse saturation current of a diode?
where do i get exercises for electronic circuits lab, i.e, designing various waveform(clipper, clamper, rectifiers)
What are the parts of network management system (nms)?
1 what is 5P00F METHOD IN 8085 MIC. PRO. 2 what is NEXT STATE FUNCTION SYNTHESIS 3 HOW THE MULTI LEVEL FAULT CAN BE DETECTED
What is the effect of if in radio receiver?
Water boiling point temperature is 100 deg. In which liquid state is convert into the gas state,but in turbine which principle is use by which exhaust temperature is 50-55 deg and is in the stage of steam?
Explain the advantages of using c band for satellite communication?
What is voltage commutation?
how does a soft starter works
What are encoders and decoders?
What happens when a magnetic material is heated strongly?