Request a Quote

Dead Weight Tester NATA Certification

Features of our dead weight tester service include:

  • NATA accreditation covering vacuum to 275,000 kPa with least uncertainty to 0.003% of reading (30ppm) for pneumatic testers and 0.005% of reading (50ppm) for hydraulic testers.
  • Software to assist with using the calibration data.
  • Overhaul and seal replacement service.
  • Weight adjustment to enable calibration adjustment of your tester to suit your local gravity.
  • Cleaning your tester and weights and flushing its hydraulic fluid.
  • Fast turnaround when you need it.
  • Experience over more than 15 years with many Manufacturers and their various models.
  • Familiar with DH-Budenberg, Pressurements, Ametek, Desgranges Et Huot, Ruska, Si Instruments, Barnet testers and more
  • Readiness to solve problems that users may experience.


To assist with the use of your dead weight tester, and to make best use of the NATA certificate, we have written a calculator program. The program is easy to use and assists with the following functions:

  • Allowance for local gravity (and calculation of local gravity).
  • Calculation of developed pressures.
  • Determining which weights are required for a test pressure.
  • Calculation of the uncertainty in the developed pressure.
  • Transfer of test data to a spreadsheet or word processor.
  • Testing instruments displaying different pressure units.

The APLPressure program, suitable for Windows, comes loaded with data from the NATA certificate.

Learn more about the APLPressure software

Re-calibration intervals:

The recommended re-calibration interval for dead weight testers used in NATA laboratories is 3 years for testers with a 0.01% of reading accuracy or better, and 5 years for testers with an accuracy above 0.01% of reading. The re-calibration period should relate to the level of use, instrument design, the accuracy expected by the user and the drift in readings observed from one calibration to the next. We can advise what might be suitable to you.