What is a deadweight tester used for?

• A. A pressure gauge
• B. A flow meter
• C. A thermometer
• D. Known weights are used to apply pressure to a fluid in order to test the accuracy of a gauge

Answer: (D)

A deadweight tester is a calibration device that uses known mechanical weights to apply precise pressure to a fluid, so you can test the accuracy of a pressure gauge. The pressure produced is determined by P = W/A, where W is the total weight placed on a piston with area A. Because the weights are fixed and the piston area is calibrated, the resulting pressure is highly reproducible and traceable, making it ideal for verifying and adjusting gauges. You connect the gauge under test to the tester, add weights to generate specific pressures, and compare the gauge reading to the known pressure. This method is different from reading a gauge directly, or from measuring flow or temperature, which is why it’s the preferred approach for calibration.