For reference pressure laboratories, we offer the DH Budenberg range of Pressure Balances for Standards laboratory applications. These items are used as National Pressure Standards in many countries including South Africa, and offer the best available uncertainties. The backbone of this range is the 5000 series. For lower pressures, the new 5111 range provides a piston large enough to have its area determined by direct measurement, providing repeatability less than 1 ppm.

Electronic Pressure Calibrators are discussed in another section.
(To review an article on choosing a calibrator, click here)

The DH Budenberg range of industrial deadweight testers is well known in South Africa as the preferred standard in most significant pressure workshops from AECI to Zincor. The units combine a high level of accessible accuracy, with the ruggedness to stand up to the ministration of trainee technicians with no ill effects.

The Industrial range consists of two standard series, plus a range of specialised products. Accuracies on average are about 0,02% of reading, and can be enhanced considerably if required.

The 550 Series is range of 5 air-operated single-piston deadweight testers built on a common base. Air operated testers are preferred for low-pressure operation, below 600 kPa. The base is rated to 12 000 kPa and is designed for an external pressure supply. Pressure is regulated using supply and release valves for coarse control, plus a volume compensator for fine control.

Model 551 has a range from 1,5 to 100 kPa, and with an optional attachment, can handle vacuum as well.
Model 552 has a range from 10 to 700 kPa.
Model 554 has a range from 20 to 2 500 kPa.
Model 556 has a range from 100 t o 7 000 kPa.
Model 558 has an oil-lubricated piston, (can be inert oil) for extended range from 100 to 12 000 kPa. This is a lower cost option than model 556.

The 580 Series is a range of 4 oil-operated deadweight testers built on a common base. Oil-operated testers are preferred for medium to high-pressure operation, above 600 kPa. The 580 base is rated to 120 MPa, and uses Budenberg’s unique dual-area screw press, for rapid priming coupled with easy generation of high pressure.

Model 580L has the lowest range, 100 to 12 000 kPa, and is a single piston design.
Model 580M is a mid-range single piston design, from 20 to 3000 kPa. Optional fine increment weights are recommended for use at the bottom end of the range.
Model 580DX is the latest version of Budenberg’s best known design, the dual concentric piston, which gives automatic range change-over, coupled with a high level of protection to the vulnerable high pressure piston. Developed in the sixties, it has never been successfully copied. The 580DX covers the range from 100 to 70 000 kPa.
The 580HX is an extended version of the DX, covering the range from 100 kPa to 120 MPa.

Designed exclusively for high pressure work, the 580EHX uses an extensively modified 580 base, coupled with a hybrid piston design, to cover the range from 100 kPa up to 260 MPa.

Special designs exist for operation up to 800 MPa, details on application.

Ametek Germany produces a range of liquid manometers to provide an alternative to pressure balances at lower pressures, and to provide differential pressure capability.

The Miniscope operates to 2 or 5 kPa with uncertainties of 0,5 Pa at gauge and differential pressures, with static pressure capability of 60 kPa.
The Manoscope operates up to 200 kPa with a 40 Pa uncertainty when used with mercury, at static pressures to 4 000 kPa. Reduced ranges are possible with other liquids. The absolute pressure version is called the Baroscope.
The Magnetic Manoscope is a high-pressure mercury manometer for ranges to 200 kPa at static pressures up to 40 MPa.