I HAVE PRESSURE TRANSMITTER WITH TWO WIRES 24 VOLTS SUPPLY.IF
TRANSMITTER WILL GIVE SIGNAL TO THE DCS WHAT HAPPEN TO THE 24
VOLTS POWER SUPPLY IT WILL DROP OR REMAIN TO 24 VOLTS POWER
SUPPLY.
Answer Posted / carl_ellis
You describe a situation with a 24Vdc power supply, a 250
ohm dropping resistor and a 2 wire loop powered transmitter
at 4.0mA
To get the voltage to vary across the transmitter, you have
to change whatever the transmitter is measuring to get its
output to change, or force an output with a HART
communicator. The loop current does not vary on its own,
it varies in response to whatever the transmitter is
measuring.
Carl's Loop Rules
The voltage across the power supply remains constant: 24Vdc
The voltage drops across the transmitter and analog input
vary with the current in the loop.
Assuming a bench setup with very short wire runs and a very
low wire resistance, then if the analog input dropping
resistor is 250 ohms, then
at 4.0mA the transmitter drops 23.0V, the AI resistor drops
1.0V
at 12.0mA the transmitter drops 21.0V, the AI resistor
drops 3.0V
at 20.0mA the transmitter drops 19.0V, the AI resistor
drops 5.0V
The sum of the voltage drops must equal the power supply
voltage.
You can bank on it.
Carl Ellis
Measure First
| Is This Answer Correct ? | 2 Yes | 0 No |
Post New Answer View All Answers
How digital input and digital output 's are working in dcs
Explain plc level and its type?
Draw a simple circuit for a well head control panel used to protect the well against fire, leak, blockage, ESD, & controls the operation of one downhole & one surface safety valve. Explain the operation and controls
How to Calibrate Radar Level Transmitter in Field
can we create an interrupt in plc through scada?
What is stripper & spilitter ? Diffrence in this.?
How r the calculation of process line mpm.
Describe how to use megger to measure the earth resistance and insulation resistance
on interface level transmitter model(RTG3302-EMERSON) What is threshold valve how can we select correct threshold value T1,T2,T3,T4 When interface water & hydro carbon
send me HPCL paper
what is moisture probe? What are there types? What is there working principle and how they works? guys this is one of technical question I had ask in interview. If you know its answer please let me know. The interviewers were more interested in microwave moisture probe, so if you find its any link please just forward me on my mail id.avinash1200@gmail.com Thanks in advance.
how to relay switch sense the fault?
How to do gas analysers calibration in AUTO and Manually by using zero and span gas?
I WANT SECURITY PAPER MILL, HOSHANGABAD TEST PAPER.KINDLY SEND TO MY MAIL ID
how to convert cubic metre per hour to newton cubic metre per hour