Additel ADT 925 is a portable hydraulic pressure test pump designed for professional pressure calibration from 85% vacuum to 6,000 psi / 400 bar. The manually operated pump combines a broad pressure range with patented screw press technology, extremely low leakage and smooth pressure adjustment. Its compact design and weight of only approximately 1.7 kg make the ADT 925 an excellent pressure source for both laboratory and field calibration.

Unlike pneumatic pressure pumps, the Additel ADT 925 uses a liquid pressure medium. Mineral oil is the standard medium, while the Additel ADT 925W is designed for applications requiring deionized water. This makes the pump particularly suitable for high-pressure calibration applications where efficient and stable hydraulic pressure generation is required.

The patented screw press technology eliminates the conventional non-returning check valve commonly found in many hand-operated hydraulic pumps. This design helps minimize leakage, reduces maintenance requirements and allows pressure to be increased and decreased smoothly.

Two hand-tight quick connectors simplify the connection of a reference pressure instrument and the device under test. Compatible instruments can be connected without conventional wrenches or PTFE tape.

At europascal, the Additel ADT 925 complements a comprehensive range of professional pressure generation and calibration equipment. In addition to supplying pressure calibration technology, europascal provides accredited calibration services for pressure and other measurement quantities. More information about professional calibration and metrological traceability is available from the europascal Calibration Service.

Your Benefits at a Glance

The Additel ADT 925 combines high hydraulic pressure generation, low leakage and portable construction in one professional manual calibration pump.

Key advantages include:

• Pressure generation from 85% vacuum to 6,000 psi / 400 bar
• Hydraulic pressure generation
• Mineral oil as standard pressure medium
• Deionized water version available as Additel ADT 925W
• Patented screw press technology
• No conventional non-returning check valve
• Extremely low leakage
• Smooth pressure increase and decrease
• 200 ml liquid reservoir
• Two-stage pressure generation
• Two hand-tight quick connectors
• Simultaneous connection of reference and test instrument
• No PTFE tape or conventional wrenches required for compatible connections
• NPT, BSP and M20 × 1.5 pressure port options
• Stainless steel and aluminum construction
• Compact dimensions
• Weight only approximately 1.7 kg
• Completely manual operation
• No electrical power required
• Minimal maintenance
• Suitable for laboratory and field calibration

Hydraulic Pressure Generation up to 400 bar

The Additel ADT 925 provides a wide hydraulic pressure range from:

85% vacuum

to:

6,000 psi / 400 bar positive pressure.

This allows the same pressure source to cover vacuum, low-pressure and demanding hydraulic high-pressure calibration applications.

Typical devices under test include:

• Analog pressure gauges
• Digital pressure gauges
• Hydraulic pressure gauges
• Vacuum gauges
• Compound pressure gauges
• Pressure transmitters
• Pressure sensors
• Pressure switches
• Pressure indicators
• Industrial process instruments

The 400 bar upper pressure limit makes the ADT 925 suitable for many industrial pressure measurement applications while retaining a compact and portable design.

Patented Screw Press Technology

A major feature of the Additel ADT 925 is its patented screw press technology.

Conventional hydraulic hand pumps frequently use non-returning or check valves within the pressure generation mechanism. These components can become sources of leakage and may require additional maintenance.

The Additel design eliminates this conventional check valve.

This provides several advantages:

• Extremely low leakage
• Smooth pressure generation
• Smooth pressure reduction
• Reduced maintenance
• Improved usability
• Reliable pressure control

The screw press mechanism enables high hydraulic pressures to be generated while allowing the operator to control pressure precisely during calibration.

Two-Stage Pressure Generation

The Additel ADT 925 uses separate mechanisms for efficient pressure generation and fine control.

A low-pressure piston provides approximately:

18 ml piston volume.

The high-pressure piston provides approximately:

0.9 ml piston volume.

The pre-pressurization mechanism is used to initially build pressure in the system.

The high-pressure screw press is then used to generate and precisely control higher pressures.

This two-stage operating principle combines efficient pressure generation with accurate adjustment of calibration points.

Extremely Low Leakage

Pressure leakage is particularly important during comparison calibration because changing pressure can make it difficult to obtain stable readings from the reference and device under test.

The Additel ADT 925 uses its patented screw press design to eliminate the troublesome check valves found in many conventional hand pumps.

This practically eliminates one common source of internal leakage.

The result is a pressure source designed for stable comparison measurements and minimal maintenance.

After reaching a calibration point, sufficient stabilization time should still be allowed before recording measurement values.

Mineral Oil as Standard Pressure Medium

The standard Additel ADT 925 uses oil as its hydraulic pressure medium.

Additel supplies mineral oil with the standard oil configuration and recommends oil when the best possible pump performance and stability are required.

The liquid reservoir has a capacity of:

200 ml.

The reservoir provides sufficient medium for typical pressure calibration applications while remaining compact enough for portable use.

Clean pressure medium is important for reliable operation. Contaminated oil should be replaced to prevent contamination and premature wear of the hydraulic system.

Additel ADT 925W for Deionized Water

For applications where oil is unsuitable, Additel offers the:

Additel ADT 925W.

This version is designed to use:

deionized water

as the pressure medium.

This can be advantageous when calibrating instruments that should not be contaminated with oil.

Additel notes that pump stability is best when oil is used and that performance can decrease when water is selected as the pressure medium.

The appropriate pump version should therefore be selected according to the requirements of the device under test and the calibration application.

Vacuum Generation up to 85%

Although primarily designed for hydraulic high-pressure generation, the Additel ADT 925 can also generate up to:

85% vacuum.

This extends the application range beyond positive pressure calibration.

The vacuum capability can be useful for:

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

The achievable vacuum is dependent on local atmospheric pressure.

Hand-Tight Quick Connectors

The Additel ADT 925 is equipped with two hand-tight quick connectors.

One connection is intended for the:

reference pressure instrument

and the second for the:

device under test.

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

This provides a major practical advantage during routine calibration, particularly when several devices must be tested consecutively.

Fast instrument changes can reduce setup time and simplify daily laboratory and field work.

Multiple Pressure Connection Options

The Additel ADT 925 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 common international pressure connection standards.

Additional adapters and fitting sets are available when the reference instrument or device under test uses another pressure connection.

Professional Comparison Calibration

The Additel ADT 925 is designed as a professional comparison pressure test pump.

A typical calibration setup consists of:

Additel ADT 925 + Reference Pressure Instrument + Device Under Test

The reference instrument and device under test are connected simultaneously to the pump.

The ADT 925 generates the required hydraulic pressure.

After the desired pressure has been reached and sufficient stabilization time has elapsed, the indication of the device under test is compared with the traceable reference value.

The procedure can be repeated at several increasing and decreasing pressure points according to the selected calibration method.

Pressure Gauge Calibration

The Additel ADT 925 is particularly suitable for pressure gauge calibration.

Typical applications include:

• Mechanical pressure gauges
• Digital pressure gauges
• Hydraulic pressure gauges
• Vacuum gauges
• Compound pressure gauges
• Precision pressure indicators

The ADT 925 provides the pressure source but does not itself provide the traceable reference pressure value.

For calibration, it is therefore combined with a suitable reference pressure instrument.

The achievable measurement uncertainty depends on the reference standard, pressure stability, environmental conditions, calibration procedure and the other contributions included in the measurement uncertainty budget.

Pressure Transmitter Calibration

The Additel ADT 925 can also provide the hydraulic pressure source for pressure transmitter calibration.

A reference pressure instrument measures the applied pressure while the electrical output of the transmitter is measured using a suitable process calibrator or precision multimeter.

For many industrial transmitters, the output signal is:

4 to 20 mA.

Several increasing and decreasing pressure points can be generated to evaluate the relationship between pressure input and electrical output.

Pressure Switch Testing

The Additel ADT 925 can also be used as the pressure source for testing pressure switches.

Pressure is gradually increased until the switch changes state and then reduced until it resets.

Combined with an appropriate reference instrument and electrical switch detector, this allows determination of:

• Switching pressure
• Reset pressure
• Switching hysteresis

The smooth pressure adjustment provided by the screw press is particularly useful when approaching switching points.

Compact and Portable Design

Despite its maximum positive pressure of 400 bar, the Additel ADT 925 is exceptionally compact.

The dimensions are approximately:

250 × 140 mm base

and:

120 mm height.

The pump weighs only approximately:

3.7 lb / 1.7 kg.

This low weight makes the ADT 925 particularly suitable for field calibration and mobile service work.

No electrical power supply is required, further increasing its flexibility for on-site calibration.

Robust Construction

The Additel ADT 925 is designed for professional laboratory and field use.

The ram and adapters are manufactured from:

stainless steel.

The body combines:

stainless steel and aluminum.

Seal materials include:

Buna-N, PTFE and copper alloy.

These materials provide a durable construction suitable for professional pressure calibration applications.

Technical Highlights

Additel ADT 925 vs. Pneumatic Pressure Pumps

The Additel ADT 925 differs fundamentally from pneumatic Additel pressure pumps such as the ADT 917, ADT 918 and ADT 920 series.

The ADT 925 uses a liquid pressure medium.

This allows high pressures to be generated efficiently in a very compact design.

The standard ADT 925 uses oil, while the ADT 925W uses deionized water.

Pneumatic pumps use air and are advantageous when the device under test must remain completely free of hydraulic fluid.

The correct pressure pump should therefore be selected according to:

• Required pressure range
• Permitted pressure medium
• Device under test
• Internal volume
• Cleanliness requirements
• Field or laboratory application

For hydraulic applications up to 400 bar where portability and low weight are important, the ADT 925 provides an especially compact solution.

Accessories for the Additel ADT 925

A comprehensive range of accessories is available for the ADT 925.

Available accessories include:

• Additel ADT 102 adapter and fitting set
• Additel ADT 103 hand-tight adapter set
• Additel ADT 100-HTK-8K flexible hose test kit
• Additel 9901-925 carrying case
• Additel ADT 925-MK maintenance kit
• Additel 9201 Diethylhexyl Sebacate oil
• Additel 9202 mineral oil

The optional carrying case accommodates one ADT 925 pump and two pressure gauges.

The ADT 925 SET configuration includes the pressure pump and carrying case.

Typical Applications

The Additel ADT 925 is suitable for:

• Hydraulic pressure calibration
• Pressure gauge calibration
• Digital pressure gauge calibration
• Pressure transmitter calibration
• Pressure sensor calibration
• Pressure switch testing
• Vacuum calibration
• Comparison pressure calibration
• High-pressure measurement
• Laboratory calibration
• Field calibration
• Industrial maintenance
• Mobile calibration services
• Research and development
• Test and measurement applications

Why Choose the Additel ADT 925?

The Additel ADT 925 combines a broad pressure range, compact construction and innovative hydraulic pressure generation technology.

Its operating range from 85% vacuum to 6,000 psi / 400 bar covers a wide variety of industrial pressure calibration applications.

Patented screw press technology eliminates the conventional non-returning check valve used in many hand pumps. This helps minimize leakage, reduces maintenance requirements and enables pressure to be increased and decreased smoothly.

A 200 ml reservoir provides sufficient pressure medium for professional calibration applications, while separate low-pressure and high-pressure pistons support efficient pressure generation and precise control.

Two hand-tight quick connectors simplify installation of the reference pressure instrument and device under test.

For applications requiring oil as the pressure medium, the standard ADT 925 provides optimum pump performance and stability. Where oil must be avoided, the Additel ADT 925W provides a version designed for deionized water.

With a weight of only approximately 1.7 kg, the ADT 925 is particularly attractive for mobile calibration and field service.

At europascal, we provide Additel pressure generation and calibration technology for professional laboratory, industrial and field applications. Our portfolio includes 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 925 is available on the official Additel website.

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