Why is an ammeter connected in series in the negative circuit during transmitter calibration?
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Why is the ammeter connected in series in the negative circuit during transmitter calibration, and why can’t it be connected in series in the positive circuit?
Today’s transmitters are all referred to as smart transmitters, and they all feature Hart protocol output. However, in the vast majority of field applications, analog output in the 4-20 milliampere range is still used. The transmitter itself contains a digital-to-analog conversion module as well as an output module, which converts the current measurement value into an electrical current signal for output; there is a comparison between the theoretical current value and the actual output value…………
What you said is different from what I asked
An ammeter can be connected in series at any position; it doesn’t matter where. . . . . .
Either the positive or negative pole will do; why is there such a requirement? Ultimately, the current only needs to be connected in series into the circuit
I haven’t heard of any such restriction; the current is the same.
Uh, I misread it; there’s no difference