Sensitivity Ratio
Transducer characterization uses a specific scaling multiplier to relate output voltage to the physical input quantity. The k_v coefficient represents this voltage sensitivity of a sensor, typically expressed in volts per unit of mechanical input. This parameter determines the scaling factor used by the data acquisition system to convert electrical measurements back into engineering units.
Voltage Calibration
Precision mechanical calibrators apply a known, steady-state physical stimulus to the sensor while a digital multimeter records the output voltage. To calculate the k_v coefficient, the measured voltage is divided by the reference input value. This calibration is repeated at multiple points across the sensor’s measurement range to determine the linearity of the scaling factor.
The resulting calibration curve serves to program the gain settings in the signal conditioning electronics.
Calibration Reference
National metrology institutes provide the primary standards against which the calibration equipment is verified. This traceability ensures that the measured k_v coefficient remains accurate and comparable across different test laboratories. The sensor certificate lists this value alongside its measurement uncertainty.
Thermal Drift
Environmental temperature changes can cause the sensitivity of the internal sensing element to vary. This variation alters the k_v coefficient and introduces measurement error if the system does not include active temperature compensation. Thermal testing defines the temperature coefficient of sensitivity to allow the system software to adjust the scaling factor dynamically in the field.
