PRESSURE MEASUREMENT SENSOR Russian patent published in 2010 - IPC G01L9/12 

FIELD: measurement equipment.

SUBSTANCE: invention refers to measurement equipment and can be used for pressure measurement. Pressure measurement sensor contains: base made from dielectric film, the main screen formed on its surface, capacitor plate, flat shaped diaphragm or with corrugated profile with edge, for example toroidal profile, packeted pins connecting the plate, diaphragm, the main screen, strain measuring bridge to external circuit. At that, internal cavity of sensor is connected to atmosphere through capillary hole. On diaphragm surface there formed is strain measuring bridge which is electrically insulated from diaphragm surface with dielectric film layer. Sensor is equipped with low frequency equipment (LFE), dc power supply, charge and voltage amplifier, subtracting unit, indicator. One of the diagonals of strain measuring bridge is connected to power supply, and the other diagonal thereof is connected via LFE to indicator and to input of subtracting unit which is connected to indicator. Capacitor output of sensor is connected through pin, charge and voltage amplifiers to inputs of subtracting unit and indicator. Strain-gauge sensing elements of strain-measuring bridge and capacitor elements of capacitor are made on "silicon-on-sapphire" basis. In addition, there introduced is protection grid, terminal block with pins, support tube with a cover, housing filled with soft sealant, two resistors and capacitors. Upper plate of capacitor sensing element of sensor is connected through cable shield to positive pole of charge amplifier. Both resistors and the second capacitor are fixed at one and the same point. The first resistor is connected to cable core, to the first capacitor and lower plate of capacitor sensing element of sensor. The second resistor is connected to positive pole of polarisation. Negative pole of polarisation source is connected to external screen and local earthing. Capacitor sensitive element and strain-measuring bridge are connected at one and the same dc power supply output and supply the pressure sensor with one and the same voltage. Subtracting unit is located inside the sensor housing.

EFFECT: improving reliability owing to compact sensor design and use as sensing element of sensor of strain-gauge and capacitor sensing element.

2 dwg