What is the impact of wiring faults on pressure transmitter performance?

• A. They can cause erroneous readings, intermittent loss of signal, or loop instability.
• B. They always improve signal quality.
• C. They have no effect if the device is loop-powered.
• D. They only affect power consumption.

Answer: (A)

Wiring faults disrupt the electrical path that a pressure transmitter relies on to send its signal. In a typical 4-20 mA loop, the transmitter adjusts current to represent pressure, so any extra resistance, loose connections, damaged insulation, or interference along the wiring changes the current the loop can carry and the voltage the transmitter sees. As a result, readings can drift or become inaccurate (erroneous readings). If a connection becomes intermittent or a short or open develops, the loop current can flicker or drop out (intermittent loss of signal). Changes in load or supply caused by wiring faults can also make the loop unstable, introducing noise and unpredictable behavior. These faults do not improve signal quality, and they can affect performance even in loop-powered configurations.