What does 4-20 mA span represent?
The 4-20 mA represents the sensor’s measurement span. The 4 mA set point is typically placed near the bottom of the empty tank, or the greatest measurement distance from the sensor. The 20 mA set point is typically placed near the top of the full tank, or the shortest measurement distance from the sensor. The sensor will proportionately generate a 4 mA signal when the tank is empty and a 20 mA signal when the tank is full.
