The Model 11901 Dual or Model 11901-A Triple Digital Barometer are designed to make accurate pressure measurements throughout a wide range of environmental conditions. Using capacitive, absolute
pressure sensor technology, excellent hysteresis as well as outstanding temperature and long-term stability are achieved. By combining the sensor with AWIs quad-plate pressure port technology,
venturi effects by wind speed are minimized contributing to the barometers exceptional repeatability. Its precision and diagnostic design make it ideal for applications requiring the highest in
performance and reliability, such as aviation and meteorological studies. Inherent Performance When the pressure changes, the silicon diaphragm bend and changes the height of the vacuum gap in the
sensor. As the vacuum changes the capacitance of the sensor changes, which is measured and converted into a pressure reading. The pressure sensor combines three powerful techniques for its superior
performance: the use of single crystal silicon as sensor material, the capacitive measurement principle and the air sampling inlet. Silicon offers good elasticity, low hysteresis, excellent
repeatability, small temperature dependence and superior long-term stability. The design of the capacitive pressure sensor was maximized for a wide dynamic range and includes a built-in
overpressure blocking mechanism. Pressure sampling is accomplished through the quad plate pressure port that negates any outside air effects through its unique air inlet design. Accuracy By Design
AWI's Dual and Triple Digital Barometer continuously compensates for pressure linearity and temperature dependency. Adjustments are made at seven temperature levels over the full operating
temperature range and seven to nine pressure levels over the operating pressure range at each temperature level. The calculated individual basic pressure and temperature adjustment coefficients are
stored in the EEPROM of each pressure transducer. The user cannot change these basic factor adjustments. Scientifically Valid Chain of Calibration Every Digital Barometer is calibrated through a
scientifically valid chain of reference. The traceability chain goes directly from the product up to the National Institute of Standards and Technology (NIST) with an unbroken chain of
calibrations. All barometers come with a factory calibration certificate which is NIST traceable. Self Diagnostics for Reliable Measurements For reliable measurements the 11901 barometer has two
pressure transducers while the 11901-A has three transducers. Software continuously checks that each transducer remains within set tolerances.
