According to some theories, a pressure transducer using 4-20 mA output signal transmit the current signal on the signal line, so its transmission distance should be unlimited. In theory, the transmission distance of the 4-20 mA current signal can be infinitely only when the impedance of the transmission cable is zero. However, this statement is for specific conditions. When the voltage of the power supply of the pressure transducer is reduced to a certain extent or the resistance of the wire is large to a certain extent, 4-20 mA current transfer signal will create a voltage drop across the line.
This paper discusses the transmission distance of the 4-20 mA signal of the pressure transducer under the premise of ensuring the specified accuracy. The essence is to discuss and determine the transmission distance allowed by the 4-20 mA signal.

Calibration is the process for adjusting the electrical signal of the pressure sensor to have a known relationship to the measured pressure. The pressure sensor must connect with the instrument for work after the calibration is completed, otherwise the required accuracy cannot be achieved and the pressure reading cannot be obtained correctly. This article will share the calibration process for pressure sensors. Each step in the process has different calibration items and technical standards.