Dear Friends

which communicator is used to configure the ABB AMD 230 Absolute pressure TX? I am facing problem at steam turbine sealing pressure transmitter..i want replace the transmitter with new one but i don't have information about the configuration of existing transmitter, while i have tried ABB 691HT communicator but unable to detect the transmitter.

 

Answer: None. This model pressure transmitter does not use a digital protocol.

Google's first hit for ABB AMD 230 is at
www05.abb.com/global/scot/...nsf/.../42_15_537_en_06_02_03.pdf

That document states:
The AMD 210/AMD 230 Transmitter consists of the D037 (2) or D057
(1) Measuring Mechanism and the amplifier with potentiometers for lower range value,span and damping (8).

Time to get out your screwdriver.

 

thanx David

i have tried to fix the issue using screw driver but could not succeed because i don't have any information about the range of transmitter. only got roughly written masking tape inside the TX where three values in mmhg against the mA. while value on HMI configured in mbar. thats why i was confused

cheers
ashiq

 

ashiq,

If a transmitter was calibrated for, say 0-30 mmHg for 4-20 mA, that would be the same as 0-39.99671 mbar for 4-20 mA.

I have seen people use "scales"/engineering units to calibrate a device that were different than those used to display the value on the screen of some operator interface. For example, say you didn't have a device or gauge capable of measuring mbar, but you did have one capable of measuring mmHg, well then you know that you needed a maximum value of 40.00 mmHg, and you found a formula or converter (probably on the Internet or World Wide Web!) to tell you that 40.00 mbar was equivalent to 30.00247 mmHg. You can use the gauge and pressure source (pump; bottled gas; etc.) to produce 30.00247 mmHg at 20 mA (by adjusting the pot for the span or gain of the transmitter) and, magically, the operator interface value would read 40.00 mbar.

It's exactly what you would do if you had a spec for a transmitter that was expressed in psig and the only gauge you had was one with a range in kpa. You would convert between psig and kpa for the calibration, right?

Or, would you tell your supervisor that you couldn't calibrate the device because you didn't have a gauge with psig scale?

 

30 mmHg is exactly equal to 39.9967105 millibars. 4-20mAa is dimensionless. If the display device had been reading in Hg, then you can just change it to read millibars. No scaling or adjustments are necessary.

Dick Caro

 

On page 8, the manual states:

"The transmitter has been calibrated by the manufacturer in accordance with the ordering information. The values for the lower and upper range values can be seen on the type plate.

The following is basically valid; in the line "Einst./Adj", the first value printed (e.g. 0 bar abs.) is always allocated to the 4mA signal and the second value printed (e.g. 6 bar abs.) always to the 20mA signal."

An image of the ID plate is shown to clarify the explanation.

The zero and span ranges are stated on the ID plate.

 

Thanks Mr. CSA, Anonymous and David

I appreciate your efforts to make this confusion clear to me..yes Mr. David is right every thing is written on the transmitter like zero and span but problem is that i don't have calibrated range and old installed transmitter sensor looks dead no any response on whole range and unable to find the ranges from the O&M manuals. DCS slave config ranges are zero= -600 and span is equal to 700.

From old transmitter i found hand written values in mmhg on masking tape paper. Guys working here before me not sure that these values or ok or not.

Some time simple things also create trouble for us..maybe this looks simple to others but i was not clear that's why i am trying to understand.

again thanks to all for contribution

ashiq