Interested to Buy Any Domain ? << Click Here >> for more details...
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.
- 1 Answers
- 4168 Views
- I also Faced
- E-Mail Answers
Answer Posted / 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 |
Post New Answer View All Answers
what is different between 2,3&4 wire rtd and how much maximum distance using plc to field.
can anyone guide me how to get any of the previous year GAIL question papers? are they available? 0n 2nd august i have to take the written test.
How can a d.p. Transmitter be calibrated?
Coal mill Instruments Equipments for cement plant And process diagram ?
What are the key features of a Distributed Control System? describing the various layers (sensor through to business system interfaces) as well as the hardware, software and security aspects of the DCS.
what are procedure of sox-nox calibration
hi friends,im an instrumentation and contol engg student,can u hlp me of suggsting barc written question paper,my id is roysuvaranjan@gmail.com, cel no.9563591747
I m appointed as an automation trainee engineer in small firm in that I am only the one , my company give me a project on s7-200 as i m beginner I don't know how to program so please send me the helpful site so that I complete my project before deadline....please help me out in this critical situation.
any body who gone thru recent iocl interview.INSTRUMENTATION questions. I need.
Explain about safety integrated level protection? . How it was differ from other protections ?
how to calibrate corollaries (Mass flow meter)?
what is a good line as ic engineer as maintenance ,oc, project, calibration ,validation engineer?
what is the PC interface and software for connection to ABB logic module “ LM011-CE18RAC “ ( for Programming ) ??
What is frequency factor in massflow meter? When using frequency output?
HOW CREATED LP & HP PRESURES IN DRUM FOR DRUM LEVEL MEASUREMENT!
