4-20 MA transmitter signal

[srinivasan]

Do you mean intrinsic safety barriers? They also contribute to voltage drop.

So far all I can glean from your posts is that you're measuring 16.5Vdc at the transmitter's terminals. IMO, that's not low enough to warrant any concern, especially if output is 20ma while measuring voltage. If it's at 4ma output, I'd be a little concerned... but I'd just do a HART analog output trim while loop powered and measure the voltage when output is 20ma. If you drop below 10.5Vdc or can't get up to 20ma or better output, then you have a problem.

Yes, barriers are analog intrinsically safe type. Our site engineer sent two pressure transmitters to our company from site saying that transmitters circuits malfunctioning. i also read full catalog before posting and i found 10.5 VDC is the minimum voltage. But no complaint about other pressure transmitters. Also these transmitters serves ESD function. that is the crucial.