Specialist in calibration, testing, and certification is now able to offer further reduced measurement uncertainties under its gold service for pressure balances
Sira Test and Certification offers three classes of accuracy in pressure balance calibration, provided by staff with an in-depth knowledge of industrial calibration and instrumentation.
35-50ppm gold service (mass and effective area) involves weighing the piston and each weight to an uncertainty of approximately 8ppm (or less if required).
The effective area of the piston assembly is determined by direct comparison with a pressure balance, calibrated at a National Standards laboratory, yielding an uncertainty of the effective area measurement which is usually less than 50ppm.
Typically, the calibrated range of the instrument is 90-95% of the working range.
100ppm silver service (standard service) calibrates instruments in a similar way to the 50ppm mass and effective area service.
The uncertainty of the principal measured pressures is around 100ppm (up to 20,000 psi) increasing to 250ppm (up to 60,000 psi).
200ppm bronze service (five point calibration); the pressure generated by the pressure balance is measured at five points across each range with an uncertainty of around 200ppm.
Sira says it is able to calibrate all makes of equipment, including dual and single piston oil operated pressure balances up to 4100bar.
Sira can also calibrate single, dual and triple piston gas operated pressure balances up to 400bar.
Sira also offers repair services as well as training courses in several areas of calibration.
