The Additel ADT 761A-D Automatic Pressure Calibrator is a portable, fully automated pneumatic pressure calibration system designed for precise gauge and differential pressure applications. It combines automatic pressure generation, closed-loop pressure control, precision pressure measurement, electrical process calibration and advanced communication functions in one powerful instrument.
The ADT 761A-D automatically generates and controls pressures from:
-13.5 to +35 psi
or:
-0.95 to +2.5 bar
The instrument supports both:
Gauge Pressure
and:
Differential Pressure
with a specified pressure accuracy of:
0.02 % FS
and pressure control stability of:
0.003 % FS
This combination makes the Additel ADT 761A-D particularly suitable for automatic calibration of differential pressure transmitters, pressure sensors, low-pressure gauges, pressure switches and process pressure instrumentation.
The ADT 761A-D can accommodate two removable internal pressure modules, allowing different pressure ranges to be combined in one calibration platform. In addition, two external pressure modules can be connected for further pressure measurement flexibility.
Integrated electrical process functions, HART and PROFIBUS PA communication, data logging and task management make the ADT 761A-D more than an automatic pressure source. It provides a complete solution for demanding professional calibration workflows.
The europascal calibration service provides professional calibration solutions for automatic pressure calibrators, differential pressure instruments, pressure modules, pressure transmitters, pressure sensors and pressure gauges.
Your Benefits at a Glance
The Additel ADT 761A-D Automatic Pressure Calibrator provides:
- Fully automatic pneumatic pressure generation
- Integrated electric pressure pump
- Pressure range from -0.95 to +2.5 bar
- Pressure range from -13.5 to +35 psi
- Gauge pressure measurement
- Differential pressure measurement
- Pressure accuracy of 0.02 % FS
- Pressure control stability of 0.003 % FS
- Two removable internal pressure modules
- Two external pressure module connections
- Automatic closed-loop pressure control
- Electrical process measurement
- mA measurement
- Voltage measurement
- mA source
- 24 V loop power
- Pressure switch testing
- HART communication
- PROFIBUS PA communication
- Automated calibration tasks
- Integrated data logging
- Wi-Fi
- Bluetooth
- USB
- Ethernet
- Portable design
- Suitable for laboratory and field calibration
Automatic Pressure Generation from -0.95 to +2.5 bar
The Additel ADT 761A-D provides automatic pneumatic pressure generation across a range of:
-0.95 to +2.5 bar
or:
-13.5 to +35 psi
The negative pressure capability allows the instrument to generate vacuum relative to atmospheric pressure, while the positive range extends to 2.5 bar.
The integrated electric pump eliminates manual pressure generation for many calibration applications.
The operator enters the required pressure setpoint and the ADT 761A-D automatically:
- Generates the required pressure
- Approaches the selected setpoint
- Regulates the pressure
- Stabilizes the pressure
- Measures the resulting reference pressure
This significantly simplifies repetitive multipoint calibration procedures.
Gauge and Differential Pressure
The ADT 761A-D supports:
Gauge Pressure
and:
Differential Pressure
Gauge pressure is measured relative to atmospheric pressure.
Differential pressure represents the difference between two applied pressures:
Δp = p₁ – p₂
The ability to work with both pressure types makes the ADT 761A-D particularly useful for industrial low-pressure and differential-pressure applications.
Unlike the ADT 761A-500, ADT 761A-1K and ADT 761A-1.5K, the ADT 761A-D is not designed as a gauge/absolute pressure configuration.
Pressure Accuracy of 0.02 % FS
Additel specifies the pressure accuracy of the ADT 761A-D as:
0.02 % FS
FS refers to the span of the installed pressure module.
Additel specifies the pressure accuracy as a one-year accuracy including one-year stability.
This is important when evaluating the instrument for a particular calibration task because the absolute accuracy contribution depends on the span of the selected internal pressure module.
Excellent 0.003 % FS Control Stability
The pressure control stability of the ADT 761A-D is specified as:
0.003 % FS
Stable pressure control is particularly important for automated calibration procedures.
After the required pressure setpoint has been generated, the integrated control system maintains a stable reference pressure so that the device under test can be evaluated under controlled conditions.
This reduces the manual adjustment normally required with conventional pressure pumps.
Two Removable Internal Pressure Modules
The Additel ADT 761A-D can accommodate:
two removable internal pressure modules
This provides an important metrological advantage.
Instead of using only the maximum 2.5 bar range for every calibration, a second lower-range module can be installed for applications requiring smaller pressures.
Because pressure accuracy is specified relative to the span of the selected module, choosing a module that closely matches the pressure range of the device under test can improve absolute measurement performance.
Flexible Multi-Range Calibration
A calibration laboratory may need to calibrate instruments with very different pressure ranges.
For example, one device may operate up to 2.5 bar while another differential pressure transmitter may cover a substantially smaller range.
The dual internal module concept allows the ADT 761A-D to be configured for both applications.
This provides greater flexibility than a pressure calibrator with only one permanently installed pressure sensor.
Two External Pressure Modules
In addition to the internal pressure modules, the ADT761A platform supports:
two external pressure modules
Compatible Additel intelligent digital pressure modules can therefore be connected for additional pressure measurement applications.
External modules extend the measurement capabilities of the system but do not increase the automatic pressure-generation limit of the internal pneumatic system.
Differential Pressure Transmitter Calibration
The Additel ADT 761A-D is particularly suitable for differential pressure transmitters.
A differential pressure transmitter determines the difference between two pressures:
Δp = pHigh – pLow
The transmitter then typically converts this pressure difference into an electrical output signal such as:
4–20 mA
The ADT 761A-D can generate the required pressure while its integrated electrical measurement functions evaluate the transmitter output.
This allows pressure and electrical measurement to be combined in a single calibration workflow.
4–20 mA Pressure Transmitter Calibration
Many industrial pressure transmitters use a standardized:
4–20 mA
output signal.
During calibration, several defined pressure points can be applied to the transmitter.
The corresponding current output can then be compared with the expected value.
Because the ADT 761A-D combines automatic pressure generation with electrical process measurement, both quantities can be evaluated with one calibration platform.
Electrical Process Measurement
The ADT761A platform provides comprehensive electrical process functions.
Current measurement ranges include:
-25 to +25 mA
and:
-50 to +50 mA
Voltage measurement ranges extend up to:
±30 V
These functions allow the ADT 761A-D to evaluate electrical output signals from pressure transmitters and other process instrumentation.
High-Accuracy mA Measurement
For the -25 to +25 mA range, Additel specifies a resolution of:
0.1 µA
with an accuracy of:
±(0.008 % RD + 1.0 µA)
This makes the electrical section suitable for precise evaluation of standard 4–20 mA process signals.
The pressure and electrical measurement functions can therefore be combined when calibrating pressure transmitters.
mA Source Function
The ADT761A can also generate current signals.
Available source ranges include:
0 to 2.5 mA
and:
2.5 to 25 mA
This expands the instrument beyond pressure calibration and allows additional process instrumentation tasks to be performed.
24 V Loop Power
The Additel ADT 761A-D provides:
24 V loop power
with a maximum load of:
50 mA
This is particularly useful for two-wire 4–20 mA pressure transmitters.
The ADT 761A-D can therefore supply the transmitter while simultaneously generating the reference pressure and measuring the electrical output.
Pressure Switch Testing
The ADT 761A-D supports pressure switch testing.
Supported switch types include:
- Mechanical switches
- NPN switches
- PNP switches
The automatic pressure control system can approach the switching point in a controlled manner.
This allows parameters such as:
- Switching pressure
- Reset pressure
- Hysteresis
to be determined efficiently.
HART Communication
The Additel ADT 761A-D supports:
HART communication
for compatible smart process instruments.
HART capability allows intelligent pressure transmitters to be integrated into the calibration workflow.
Depending on the connected instrument, this can support:
- Device identification
- Reading digital measurement values
- Configuration
- Diagnostics
- Calibration functions
PROFIBUS PA Communication
The ADT761A platform also supports:
PROFIBUS PA
communication.
This provides additional flexibility when working with compatible digital process instrumentation.
The combination of pressure generation, electrical measurement and digital communication makes the ADT 761A-D particularly suitable for modern process calibration applications.
Automated Calibration Tasks
The Additel ADT 761A-D supports automated calibration tasks and task management.
A calibration procedure can contain several defined pressure points.
The calibrator can automatically generate the required pressures and support documentation of the corresponding measurement results.
This improves repeatability and reduces manual work during repetitive calibration procedures.
Integrated Data Logging
The ADT761A provides integrated data logging.
Additel specifies storage capacity for up to:
1,000,000 time- and date-stamped readings
This functionality is useful for:
- Calibration documentation
- Pressure stability testing
- Long-term measurements
- Process monitoring
- Instrument evaluation
- Troubleshooting
Wi-Fi, Bluetooth, USB and Ethernet
The Additel ADT 761A-D provides several communication interfaces:
- Wi-Fi
- Bluetooth
- USB
- Ethernet
These interfaces simplify integration into modern calibration environments and allow communication with computers and compatible equipment.
Portable Automated Calibration
The ADT 761A-D combines automatic pressure generation with a portable architecture.
This is particularly useful for field calibration applications where the device under test cannot easily be removed from an industrial installation.
Instead of transporting the pressure transmitter or pressure gauge to a stationary pressure controller, the automatic calibration system can be taken to the measurement location.
Applications in Process Instrumentation
The ADT 761A-D is particularly suitable for industrial process pressure applications.
Typical devices include:
- Differential pressure transmitters
- Gauge pressure transmitters
- Pressure sensors
- Pressure transducers
- Pressure gauges
- Pressure switches
- 4–20 mA transmitters
- HART transmitters
- PROFIBUS PA instruments
The combination of automatic pressure generation and integrated electrical functions provides a comprehensive calibration solution.
Differential Pressure Applications
Differential pressure is widely used in industrial measurement technology.
Typical applications include:
- Filter monitoring
- Flow measurement
- Tank level measurement
- Process pressure measurement
- Air and gas systems
- Differential pressure transmitters
For flow measurement, differential pressure may be generated across primary elements such as:
- Orifice plates
- Venturi tubes
- Flow nozzles
- Pitot tubes
The ADT 761A-D can be used to generate controlled differential pressures for calibration of the associated measurement instrumentation.
Technical Highlights
Model: Additel ADT 761A-D
Device type: Automatic Pneumatic Pressure Calibrator
Pressure range: -13.5 to +35 psi
Pressure range: -0.95 to +2.5 bar
Maximum positive pressure: 35 psi / 2.5 bar
Pressure types: Differential and Gauge
Absolute pressure: No
Pressure accuracy: 0.02 % FS
Pressure control stability: 0.003 % FS
Internal pressure modules: 2
Internal modules: Removable
External pressure modules: 2
Pressure generation: Integrated electric pump
Pressure control: Fully automatic
Electrical process measurement: Yes
mA measurement: Yes
Voltage measurement: Yes
mA source: Yes
24 V loop power: Yes
Pressure switch testing: Yes
HART communication: Yes
PROFIBUS PA communication: Yes
Task management: Yes
Data logging: Yes
Data storage: Up to 1,000,000 readings
Wi-Fi: Yes
Bluetooth: Yes
USB: Yes
Ethernet: Yes
Technical Data
| Feature | Additel ADT 761A-D |
|---|---|
| Device type | Automatic Pneumatic Pressure Calibrator |
| Pressure range | -13.5 to +35 psi |
| Pressure range | -0.95 to +2.5 bar |
| Maximum positive pressure | 35 psi / 2.5 bar |
| Pressure types | Differential / Gauge |
| Absolute pressure | No |
| Accuracy | 0.02 % FS |
| Control stability | 0.003 % FS |
| Internal pressure modules | 2 |
| Internal modules removable | Yes |
| External pressure modules | 2 |
| Automatic pressure generation | Yes |
| Integrated electric pump | Yes |
| Electrical process calibration | Yes |
| mA measurement | Yes |
| Voltage measurement | Yes |
| mA source | Yes |
| 24 V loop power | Yes |
| Pressure switch test | Yes |
| HART | Yes |
| PROFIBUS PA | Yes |
| Task management | Yes |
| Data logging | Yes |
| Communication | Wi-Fi, Bluetooth, USB, Ethernet |
ADT 761A-D vs. ADT 761A-LLP
The ADT 761A-D and ADT 761A-LLP both support gauge and differential pressure, but they cover different pressure ranges.
| Feature | ADT 761A-LLP | ADT 761A-D |
|---|---|---|
| Minimum pressure | -75 mbar | -0.95 bar |
| Maximum pressure | +75 mbar | +2.5 bar |
| Pressure types | Gauge / Differential | Gauge / Differential |
| Accuracy | 0.05 % FS | 0.02 % FS |
| Control stability | 0.003 % FS or 0.05 Pa | 0.003 % FS |
| Internal modules | 2 | 2 |
| External modules | 2 | 2 |
The ADT 761A-LLP is optimized for very low differential pressures.
The ADT 761A-D significantly extends the pressure range to +2.5 bar while retaining differential and gauge pressure capability.
ADT 761A-D vs. ADT 761A-500
The ADT 761A-D and ADT 761A-500 target different applications.
| Feature | ADT 761A-D | ADT 761A-500 |
|---|---|---|
| Pressure range | -0.95 to +2.5 bar | -0.9 to +35 bar |
| Differential pressure | Yes | No |
| Gauge pressure | Yes | Yes |
| Absolute pressure | No | Yes |
| Accuracy | 0.02 % FS | 0.01 or 0.02 % FS |
| Control stability | 0.003 % FS | 0.003 % FS |
The ADT 761A-D should be selected when differential pressure capability is required.
The ADT 761A-500 provides a much higher positive pressure range and absolute pressure capability, but it does not provide the differential pressure configuration of the D model.
ADT 761A Series Overview
The ADT761A family covers a wide range of automated pneumatic pressure calibration applications.
| Model | Pressure Range | Pressure Type |
|---|---|---|
| ADT 761A-LLP | ±75 mbar | Gauge / Differential |
| ADT 761A-D | -0.95 to +2.5 bar | Gauge / Differential |
| ADT 761A-500 | -0.9 to +35 bar | Gauge / Absolute |
| ADT 761A-1K | -0.9 to +70 bar | Gauge / Absolute |
| ADT 761A-1.5K | -0.9 to +100 bar | Gauge / Absolute |
| ADT 761A-BP | 100 to 1,200 hPa | Absolute |
The ADT 761A-D therefore occupies an important position between the ultra-low-pressure LLP model and the higher-pressure gauge/absolute configurations.
Typical Calibration Applications
The Additel ADT 761A-D Automatic Pressure Calibrator is particularly suitable for calibration and testing of:
- Differential pressure transmitters
- Gauge pressure transmitters
- Pressure sensors
- Pressure transducers
- Digital pressure gauges
- Analog pressure gauges
- Pressure switches
- 4–20 mA pressure transmitters
- HART pressure transmitters
- PROFIBUS PA instruments
- Pneumatic process instrumentation
- Industrial pressure measuring equipment
Typical users include:
- Professional calibration laboratories
- Industrial maintenance departments
- Process industry
- Chemical industry
- Pharmaceutical industry
- Energy and power generation
- Instrument manufacturers
- Quality assurance departments
- Mobile field service
Calibration and Service by europascal
Regular calibration of the ADT 761A-D is important for maintaining reliable metrological performance.
When two internal pressure modules are installed, both modules should be considered when defining the required calibration scope.
The differential pressure configuration should also be taken into account when defining suitable calibration points and connections.
The europascal calibration service provides professional calibration solutions for automatic pressure calibrators, differential pressure instruments, pressure modules, pressure sensors, pressure transmitters and pressure gauges.
europascal can also support customers in selecting the appropriate ADT 761A configuration, internal pressure modules, external pressure modules and accessories.
Why Choose the Additel ADT 761A-D?
The Additel ADT 761A-D Precise Automatic Pressure Calibrator combines fully automatic pneumatic pressure generation from -0.95 to +2.5 bar, 0.02 % FS pressure accuracy and excellent 0.003 % FS pressure control stability.
Its support for both gauge and differential pressure makes the D configuration particularly useful for calibration of differential pressure transmitters and industrial pressure instrumentation.
Two removable internal pressure modules provide flexibility for different pressure ranges, while two external pressure module connections further expand measurement capability.
Integrated electrical process measurement, mA sourcing, 24 V loop power, pressure switch testing, HART and PROFIBUS PA communication, task management and data logging make the ADT 761A-D a comprehensive solution for professional automated pressure calibration.
Looking for the Additel ADT 761A-D for automatic gauge and differential pressure calibration up to 2.5 bar? Contact europascal for expert advice, suitable pressure module configurations, accessories and professional calibration services.
Further information about the Additel ADT 761A series from europascal can be found here.
Further pressure calibration products from europascal can be found here.
Manufacturer information about the Additel ADT 761A-D can be found on the official Additel website.
