Dead Weight Tester

Dead weight testers are a piston-cylinder type measuring device. As primary standards, they are the most accurate instruments for the calibration of electronic or mechanical pressure measuring instruments.

DWT (Dead Weight Tester) is based on the principle of Pascal's law. The law states that in a closed system of incompressible fluid, the pressure applied will exert an equal amount of force in all the directions. In the DWT system, silicon oil is used within the closed boundaries of the Piston cylinder arrangement, piping, pressurisation chamber and in the head on which the gauge to be tested/ calibrated is fixed.

They work in accordance with the basic principle that P= F/A, where the pressure (P) acts on a known area of a sealed piston (A), generating a force (F). The force of this piston is then compared with the force applied by calibrated weights. The use of high quality materials result in small uncertainties of measurement and excellent long term stability.

Today's dead weight testers are highly accurate and complex and can make sophisticated physical compensations. They can also come accompanied by an intelligent calibrator unit which can register all critical ambient parameters and automatically correct them in real time making readings even more accurate.