What is the basic procedure to calibrate a pressure transducer with a reference pressure source?

• A. Calibrate using a single reference pressure and assume linearity.
• B. Compare outputs to a standard and adjust by trial.
• C. Expose sensor to known pressures, record output, fit a linear calibration equation across the range, and apply temperature compensation if needed.
• D. Calibrate using a fixed test bench without reference pressures.

Answer: (C)

Calibrating a pressure transducer means building a reliable map between its electrical output and the actual pressure by using known reference pressures. The proper method is to expose the sensor to several known pressures across its operating range (including zero and progressively higher points), record the corresponding outputs, and then fit a calibration equation that describes how output relates to pressure. In practice this is often a linear relationship P = a·V + b, though a small nonlinear term can be added if needed. If temperature affects the sensor, you would include temperature compensation—either by taking measurements at controlled temperatures or by incorporating a compensation model—so the calibration stays accurate under operating conditions. Once the equation is established, you apply it to convert future outputs into pressure readings.

Using only a single reference pressure and assuming linearity ignores offset, gain drift, and any nonlinearity over the range, leading to errors. Relying on comparison to a standard and adjusting by trial isn’t a systematic or traceable calibration method, and calibrating with a fixed bench without known input pressures provides no anchor to actual pressure values.