Additel ADT 912A is a precise low pressure test pump designed for professional pneumatic pressure calibration from 95% vacuum to 60 psi / 4 bar. The manually operated pump combines extremely fine pressure adjustment, excellent stability and convenient hand-tight connections in a compact calibration solution. With an adjustment resolution down to 0.1 Pa / 0.001 mbar, the Additel ADT 912A is particularly suitable for calibrating low-pressure gauges, pressure transmitters, pressure sensors and other sensitive pneumatic measuring instruments.

The pump uses clean air as the pressure medium and requires no electrical power or external compressed-air supply. Its high-quality screw press provides precise fine adjustment, while an isothermal bellows chamber reduces the influence of environmental temperature changes on pressure stability. A specially designed bellows minimizes leakage, and an integrated shut-off valve isolates the air in the isothermal chamber during calibration.

Two practical hand-tight connectors allow the reference pressure gauge and the device under test to be connected directly to the pump without PTFE tape or wrenches. The result is a highly practical comparison pressure source for professional laboratory, workshop and field calibration.

At europascal, the Additel ADT 912A complements a comprehensive portfolio of pressure generation and calibration equipment. In addition to supplying professional calibration technology, europascal provides accredited calibration services for pressure measuring instruments. Find more information at the europascal Calibration Service.

Your Benefits at a Glance

The Additel ADT 912A combines a broad low-pressure range with extremely fine adjustment and excellent pressure stability.

Key advantages include:

• Pneumatic pressure generation from 95% vacuum to 60 psi / 4 bar
• Extremely fine adjustment down to 0.1 Pa / 0.001 mbar
• Air as pressure medium
• Completely manual operation
• No electrical power required
• No external compressed-air source required
• High-quality screw press for fine adjustment
• Isothermal bellows chamber for excellent pressure stability
• Specially designed bellows to minimize leakage
• Shut-off valve for isolating the pressure chamber during calibration
• No conventional check valve
• Integrated gas-liquid isolator
• Protection against moisture and contamination
• Two hand-tight quick connectors
• Reference and device under test can be connected simultaneously
• No PTFE tape or wrenches required for compatible connections
• Different NPT, BSP and M20 × 1.5 versions available
• Portable design
• Weight only approximately 2.8 kg
• Minimal maintenance
• Optional carrying case and accessories
• Ideal for low-pressure comparison calibration

Pressure Generation from 95% Vacuum to 4 bar

The Additel ADT 912A is specifically designed for low pneumatic pressure generation.

Its operating range extends from:

95% vacuum

to:

60 psi / 4 bar positive pressure.

This combination allows both vacuum and positive pressure instruments to be tested using one manual pressure pump.

The ADT 912A is therefore considerably more versatile than a pressure source designed exclusively for positive pressure.

Typical devices under test include:

• Low-pressure gauges
• Digital pressure gauges
• Vacuum gauges
• Pressure transmitters
• Pressure sensors
• Pressure switches
• Pneumatic indicators
• Process measuring instruments

The ability to generate vacuum and positive pressure also makes the pump particularly useful for instruments whose measurement range crosses atmospheric pressure.

Fine Adjustment Down to 0.1 Pa

One of the key advantages of the Additel ADT 912A is its extremely fine pressure adjustment.

Additel specifies an adjustment resolution of:

0.1 Pa

or:

0.001 mbar.

A high-quality screw press enables the operator to approach individual calibration points with very fine control.

This is particularly important for low-pressure calibration.

At low pressures, even a very small change in internal volume can cause a significant pressure change relative to the calibration point. A conventional hand pump may therefore make it difficult to set the required pressure precisely.

The fine adjustment mechanism of the ADT 912A provides significantly greater control when approaching and stabilizing individual calibration points.

Excellent Pressure Stability

Fine pressure generation alone is not sufficient for professional calibration. Once a calibration point has been reached, the pressure must remain stable enough to compare the reference instrument with the device under test.

The Additel ADT 912A has therefore been designed specifically for excellent pressure stability.

Additel uses an isothermal chamber concept to reduce the influence of environmental temperature changes.

This is particularly important because gas pressure can react noticeably to temperature changes.

Even touching parts of a conventional pneumatic pressure system can introduce heat and temporarily change the pressure.

The construction of the ADT 912A is designed to minimize these effects.

Isothermal Bellows Chamber

At the heart of the stability concept is an:

isothermal bellows chamber.

The pressure chamber is insulated to reduce the influence of environmental temperature changes.

A specially designed bellows also helps minimize leakage.

Together, these design features improve the stability of the generated pressure and make the Additel ADT 912A particularly suitable for sensitive comparison measurements.

For best calibration results, sufficient stabilization time should nevertheless be allowed before the reference and device-under-test readings are recorded.

Integrated Shut-Off Valve

The Additel ADT 912A includes a shut-off valve that closes the air inside the isothermal chamber during calibration.

Once the required pressure has been generated and adjusted, the chamber can therefore be isolated.

This contributes to stable pressure conditions during the actual comparison measurement.

The combination of:

• Isothermal chamber
• Low-leakage bellows
• Shut-off valve
• Precision screw adjustment

creates a pressure generation system specifically optimized for low-pressure calibration.

No Conventional Check Valve

Many conventional pneumatic hand pumps use a check valve or non-return valve as part of their pressure generation mechanism.

The Additel ADT 912A does not use a conventional check valve.

Additel specifically identifies this design feature as one of the reasons for the excellent stability of the pump.

Conventional check valves and poorly insulated pressure chambers can contribute to pressure fluctuations caused by environmental temperature changes or by touching the pump.

The ADT 912A is designed to minimize these effects.

Air as Pressure Medium

The Additel ADT 912A uses:

air

as the pressure medium.

No hydraulic oil is required.

This makes the pump especially suitable for pneumatic instruments and reduces the risk of oil contamination in sensitive devices under test.

The pneumatic operating principle is also convenient for laboratory and field applications because no hydraulic fluid needs to be filled or replaced during normal operation.

For special oil-free applications, the exact requirements should be discussed with Additel or europascal.

Integrated Gas-Liquid Isolator

The Additel ADT 912A incorporates a gas-liquid isolator.

This component helps protect the pump against:

• Moisture
• Dirt
• Contamination from the device under test

This is particularly useful during everyday calibration work, where instruments arriving from industrial processes may contain small amounts of contamination.

Protecting the internal pneumatic system contributes to reliable operation and reduces maintenance requirements.

Hand-Tight Quick Connectors

Two hand-tight connectors are installed on the Additel ADT 912A.

One connection is intended for the:

reference pressure gauge

while the second connection is used for the:

device under test.

Compatible instruments can be connected and disconnected without conventional wrenches or PTFE tape.

This provides a significant practical advantage in calibration laboratories where several devices may need to be calibrated consecutively.

Instrument changes can be performed quickly while reducing the amount of additional tooling required at the workstation.

Different Pressure Connections

The Additel ADT 912A is available with several pressure port configurations.

Available versions include:

• 1/4 NPT female
• 1/2 NPT female
• 1/4 BSP female
• 1/2 BSP female
• M20 × 1.5 female

This allows the pump to be configured for different international pressure connection standards.

Suitable adapters and fittings are also available when the reference instrument or device under test uses another connection type.

Professional Comparison Calibration

The Additel ADT 912A is designed as a comparison test pump.

A typical calibration setup consists of:

Additel ADT 912A + Reference Pressure Gauge + Device Under Test

The reference instrument and the device under test are connected simultaneously to the two pressure ports.

The operator manually generates the required pressure and uses the fine adjustment mechanism to approach the desired calibration point.

After the pressure has stabilized, the indication of the device under test is compared with the traceable reference value.

The process can then be repeated at several increasing and decreasing calibration points.

This straightforward comparison method makes the ADT 912A an excellent pressure source for manual calibration systems.

Pressure Gauge Calibration

The Additel ADT 912A is particularly suitable for calibrating low-pressure and medium-pressure gauges within its pressure generation range.

Typical applications include:

• Analog pressure gauges
• Digital pressure gauges
• Vacuum gauges
• Compound pressure gauges
• Low-pressure reference instruments

Combined with a suitable reference pressure gauge, the pump provides the pressure required to perform a professional comparison calibration.

The measurement uncertainty of the complete calibration depends primarily on the reference instrument, environmental conditions, calibration procedure and pressure stability.

Pressure Transmitter Testing

The Additel ADT 912A can also be used as a manual pressure source for pressure transmitter calibration.

The pump generates the pneumatic input pressure while a suitable reference instrument measures the actual applied pressure.

The electrical output of the transmitter can then be measured with an appropriate process calibrator or precision multimeter.

For a conventional process transmitter, this output is commonly:

4 to 20 mA.

This setup allows the relationship between applied pressure and electrical transmitter output to be determined at several calibration points.

Vacuum Calibration

Because the Additel ADT 912A can generate up to 95% vacuum, it can also be used for many vacuum-related calibration tasks.

This makes it possible to test instruments below atmospheric pressure without requiring a separate electrically operated vacuum pump for many applications.

Typical devices include:

• Vacuum gauges
• Compound pressure gauges
• Vacuum switches
• Vacuum transmitters
• Pressure sensors

The ability to move between vacuum and positive pressure with one manual pump provides considerable flexibility.

Portable and Independent Operation

The Additel ADT 912A is completely manually operated.

It requires:

no electrical power

and:

no external compressed-air supply.

This makes the pump particularly attractive for field calibration.

The pump weighs approximately:

2.8 kg / 6.2 lb.

Its base measures approximately:

273 × 258 mm

with a height of approximately:

140 mm.

The result is a compact but stable working platform suitable for both mobile and laboratory calibration.

Minimal Maintenance

The Additel ADT 912A has been designed for minimal maintenance.

Its pneumatic operating principle eliminates the need for hydraulic oil during normal operation.

The integrated gas-liquid isolator also helps protect the internal pump components from moisture and contamination.

Additel offers a dedicated maintenance kit for the ADT 912A when servicing becomes necessary.

Correct operation, clean connections and appropriate storage help maintain reliable performance over the service life of the pump.

Accessories for the Additel ADT 912A

Several accessories are available to expand the application possibilities of the pump.

These include:

• ADT 912A test kits
• Connection hoses
• Pressure adapters
• Additel ADT 102 adapter sets
• Additel ADT 103 hand-tight adapter sets
• High-pressure hose test kits
• Carrying case
• Differential pressure gauge holder
• ADT 912A maintenance kit

The appropriate accessories depend on the pressure connections of the reference instrument and device under test.

The SET version of the pump includes a carrying case for convenient transportation and storage.

Technical Highlights

Additel ADT 912A vs. Additel ADT 901

The Additel ADT 912A and Additel ADT 901 are both designed for precise pneumatic low-pressure calibration, but their pressure ranges are different.

The Additel ADT 901 focuses on very low pressure generation around atmospheric pressure.

The Additel ADT 912A significantly extends the positive pressure range to:

60 psi / 4 bar

while still providing:

95% vacuum.

Both concepts provide very fine pressure adjustment down to 0.1 Pa, making them suitable for sensitive low-pressure calibration.

The ADT 912A is therefore particularly useful when one manual pneumatic pump needs to cover both vacuum and positive pressures up to 4 bar.

Typical Applications

The Additel ADT 912A is suitable for:

• Low-pressure calibration
• Pneumatic pressure calibration
• Vacuum calibration
• Pressure gauge calibration
• Digital pressure gauge calibration
• Compound pressure gauge calibration
• Pressure transmitter testing
• Pressure sensor testing
• Pressure switch testing
• Comparison calibration
• Calibration laboratories
• Field calibration
• Industrial maintenance
• Service applications
• Research and development
• Pneumatic test systems

Why Choose the Additel ADT 912A?

The Additel ADT 912A combines a useful pressure range, extremely fine adjustment and excellent pressure stability in one portable manual pressure source.

Its range from 95% vacuum to 60 psi / 4 bar allows both vacuum and positive-pressure devices to be calibrated using the same pump.

An adjustment resolution down to 0.1 Pa / 0.001 mbar provides excellent control when approaching sensitive calibration points.

The isothermal bellows chamber reduces the influence of environmental temperature changes, while the specially designed bellows helps minimize leakage. An integrated shut-off valve isolates the chamber during calibration and contributes to stable measurement conditions.

Two hand-tight quick connectors simplify the connection of a reference instrument and device under test without requiring PTFE tape or conventional wrenches.

The built-in gas-liquid isolator protects the pump against moisture and contamination, supporting reliable operation and minimal maintenance.

With a weight of only approximately 2.8 kg and no requirement for electricity or an external pressure source, the ADT 912A is equally suitable for laboratory and field calibration.

At europascal, we provide Additel pressure generation and calibration equipment for professional laboratory, industrial and field applications. The portfolio includes manual pneumatic and hydraulic pressure pumps, digital pressure gauges, pressure calibrators, pressure modules and automated pressure calibration solutions.

For professional calibration and metrological traceability of pressure measuring instruments, visit the europascal Calibration Service.

Further Additel products are available from europascal.

Manufacturer information about the Additel ADT 912A is available on the official Additel website.

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