Vaisala PTB330TS - Manual (Page 22)

User's Guide ______________________________________________________________________
20 ___________________________________________________________________M210983EN-A
0810-032 Figure 3 PTB330 Barometer in Tabletop Casing
Pressure Measurement Principle
PTB330 uses a BAROCAP
®
silicon capacitive absolute pressure sensor
developed by Vaisala for barometric pressure measurement
applications. The BAROCAP
®
sensor has excellent hysteresis and
repeatability characteristics, low temperature dependence and a very
good long-term stability. The ruggedness of the BAROCAP
®
sensor is
outstanding and the sensor is resistant to mechanical and thermal
shocks.
The measurement principle of the PTB330 is based on an advanced RC
oscillator and reference capacitors against which the capacitive pressure
sensor is continuously measured. The microprocessor of the barometer
performs compensation for pressure linearity and temperature
dependence.
PTB330 can be ordered with 1 ... 3 barometer modules. The use of more
than one module provides increased accuracy and fault tolerance.
Numbers refer to Figure 3 on page 20 :
1 = MI70 holder
2 = M12 connector for MI70 connection
3 = Pressure port