how the 4 to 20 mA signal goes to any
controller/indicator,and what is the role of voltage ,12/24
and how to do connection of it, in controller.
Answer / carl_ellis
For a 2 wire loop powered transmitter, a DC power supply
supplies power to the transmitter to power its electronics.
The transmitter uses about 3.5mA of the loop current to run
its electronics.
The transmitter's electronics measures a physical property
(temperature/pressure) which creates a measurement value
associated with engineering units. The transmitter
regulates the loop current between 4.0 and 20.0 mA (by
varying its internal resistance to drop whatever voltage is
needed to create the correct current) so the current
represents a measurement proportional to the scale
configured for that physical property.
The controller/indicator is the primary 'load' with an
analog input that has a dropping resistor. The dropping
resistor creates an IR (voltage) drop the
controller/indicator uses for its A/D conversion.
A 2 wire loop powered transmitter has a lift-off voltage,
the minimum voltage needed to operate the transmitter with a
zero ohm load. As the loop load voltage increases, the
minimum voltage required to power the transmitter and the
loop load increases.
24Vdc is the typical, nominal power supply voltage used in
the process industries. Many 2 wire loop powered
transmitters will function with supply voltages up to about
40Vdc. Higher supply voltages are needed with long copper
wire runs where the wire resistance becomes a significant
load factor.
Carl Ellis
Measure First
Is This Answer Correct ? | 0 Yes | 0 No |
which type of filter gives the constant phase characteristics?
Yokogawa dcs nodes advantages?
how to check earthing,what is minum ohms for proper earthing
How will you select suitable Instrument for Process line/Tank/Vessel?
Why mixer nd grinder Is example of constant torque load not variable torque load ???
What are different types of control valves?
what is compensation? temprature & pressure
How to convert milliampares into flow??
What is the working principal of Mass flow transmitter?
How can I read the electrical drawing easily?
what is full form of SMART
46 Answers Infosys, ITC Infotech, Lanco, Rosemount, Solvay,
In RS 500 SLC 5/03 input change one module card to another card, plz. give steps clearly.