The Additel ADT773 is an automated pressure controller and generator purpose-built for low differential pressure calibration. Unlike traditional setups that require a separate pump, regulator, and reference gauge, the ADT773 integrates an internal air pump with precision control electronics in a single instrument. It achieves control stability better than 0.003% of full scale and settles to within 0.005% FS in under 10 seconds for a 20% step change with a 50 mL load. Two interchangeable module bays accept any ADT151 differential pressure cartridge, and an optional barometric reference module enables absolute pressure measurements.

How does the modular cartridge system work?

The ADT773 features two front-loading bays that accept interchangeable ADT151 pressure modules. Each module defines the pressure range and accuracy for its channel—swap a ±2 inH₂O module for a ±400 inH₂O module in seconds without recalibrating the base unit. This modularity means one controller can cover everything from cleanroom differential pressure verification to industrial transmitter calibration across a 2,500 inH₂O span. An optional third bay can house a barometric reference module, giving the controller absolute pressure capability without an external barometer.

Which pressure modules are available?

Two base model variants are offered: the ADT773-LLP covers −380 to +400 inH₂O (1 bar), while the ADT773-D extends the maximum range to +2,500 inH₂O (7 bar). Both support differential and gauge pressure modes, and a contamination prevention system (CPS) is available for applications involving dirty or wet process media.