AA02A Baratron

General performance transducers
The AA02A Baratron manometer is an advanced general purpose absolute heated capacitance manometer developed specifically for use in vacuum and pressure measurement applications where high accuracy and excellent repeatability are crucial to process success.

These capacitance manometers are internally heated to 45°, 80°, or 100°C. They use state-of-the-art digital architecture throughout to produce the highest possible long-term performance and reliability.

Key features

  • Full scale pressure measurement from 0.1 to 1000 Torr
  • Sensor heated to 45°, 80°, or 100°C for up to 0.10% of reading accuracy
  • Fully welded sensor built entirely from Inconel and Incoloy nickel alloys
  • 0 to 10 VDC analog output proportional to absolute pressure
  • Pushbutton zero adjustment of zero position up to 20% of full scale
  • All-digital architecture and improved thermal management for long-term stability, improved accuracy, and increased reliability

Baratron Capacitance Manometer Technology

Capacitance manometers are electro-mechanical gauges that can measure both pressure and vacuum. The capacitance gauge translates a pressure-modulated movement in a thin diaphragm into an electrical signal proportional to the pressure. The pressure sensor is the thin diaphragm that is exposed to the pressure or vacuum being measured via the inlet tube. An electrode is mounted in the reference cavity behind the diaphragm. Pressure differences between the process and the reference cavity deflect the diaphragm slightly, changing the distance between it and the electrode. Variations in this distance produce variations in the capacitance between the diaphragm and the electrode creating an electrical signal that is proportional to the pressure change. Since differences in the capacitance signal are produced by physical changes within the manometer and not by changes in the gas properties, pressure measurements by the capacitance manometer are independent of the composition of the gas being measured.

Percent of Reading Accuracy

Accuracy is specified as a percent of Reading, not Full Scale, as seen in some of the lower performance devices. Percent of Reading accuracy provides you with an even more accurate output signal in the lower scale of the pressure range, where it is needed most.

Absolute Pressure Measurement

These Baratron pressure transducers are referenced to vacuum for absolute pressure measurement. Applications include: vacuum furnaces, freeze-drying of fruits and vegetables, gas lasers, automotive component testing, bottle coatings, and vacuum distillation.

Inconel and Incoloy Construction

These pressure transducers feature Inconel and Incoloy nickel alloy construction of the pressure sensor allowing it to operate without damage in virtually any chemical environment, including halogens, deionized water and steam, and ozone. The sensor is fully welded with no intermediate brazing or joining materials.

Internally Heated to 45°, 80°, or 100°C

These capacitance manometers are internally heated for improved accuracy. Unheated versions are exposed to ambient temperature variations which can degrade the sensor accuracy. These devices have the sensor enclosed in a volume that is maintained at a constant temperature above ambient. This solution improves the manometer’s accuracy and repeatability and lowers instrument drift by reducing or eliminating process contamination within the manometer. Heated manometers are recommended for applications that require maximum accuracy and repeatability, operate above ambient temperature and for those processes that employ hot gases.

KRISTIAN FLODSTRÖM Product specialist Vacuum technology 010-155 03 11