Millivolt per Volt Output Signal (mV/V, mV/V/bar, mV/V/psi)

It is an electrical signal which is proportional to the applied excitation voltage and is also referred to as a ratio-metric or strain gauge output.

This type of output signal is produced by a wheatstone bridge strain gauge transducer which converts imbalance in bridge resistance generated by an applied force / load to a voltage drop between two opposite corners of the wheatstone bridge circuit.

For a given fixed force, load or pressure, the voltage drop across two opposite corners of the circuit is linearly proportional to the voltage supplied between the adjacent two corners of the circuit. In a circuit diagram the wheatstone bridge is usually shown as four resistors representing the strain gauges, joined together in a diamond shape.

The output from a strain gauge sensor is directly influenced by changes in the supply voltage and the relationship between the two is expressed as a ratio of the full scale output voltage divided by the input supply voltage:

e.g. If a transducer has a 10 volt supply which generates a 100 milli-volt signal at full range it will have an output sensitivity of 10 mV / V.

Since the output from a transducer is also linearly proportional to the force, load or the pressure being measured, the measurement units can also be incorporated into the output sensitivity specification:

e.g. If a 60 bar pressure transducer has a 3 mV/V output sensitivity, an alternative way of describing the output characteristic is to write it as 0.05 mV/V/bar.