A Wide Range Pressure Sensor Based On Pilani Effect

High altitude meteorlogical observation mainly include temperature, humidity,barometric pressure and wind speed From the ground to the 30 thousand meters between the different height in the atmosphere. The accuracy of the barometric pressure, which is one of the basic meteorological elements, directly affects the the climate system analysis and forecast results.The barcmetric pressure sensor for high altitude detection, is usually made to achieve to measuring wide range of air pressure from atmospheric pressure to ultra low pressure(lOhPa). In this thesis, a wide range pressure sensor based on the Pirani effect is proposed. For the pressure range of 10 hPa ? 300 hPa, a low- barometric pressure sensor based on the Pirani effect is proposed. A probe design scheme for a dual-cavity structure that separates the heating element from the temperature sensing element and maps a reference cavity is proposed. A computational fluid dynamic method is utilized to analyze the heat transfer of the sensor of the sensor probe. To realize the functions of high-accuracy measurement, an ARM Cortex-M processor,STM32F103is chosen here as the main control unit. PT1000 is utilized as the temperature sensor device, in combination with an A/D convertor AD7794, which features low noise. A constant power heating control circuit are also implemented in the circuit.For the pressure range of 300 hPa ?1100 hPa, four high precision digital pressure sensors BMP 180 are used to build the sensor array, which reduce the system error caused by the creep of the sensor and improve fault tolerance and complementary of barometric pressure detection. This paper developed supporting PC software based on C# in order to in order to collect data. The experimental results show that the reading accuracy of the sensor proposed in this paper is less than 10%and the resolution is on the order of 0.1 hPa, during the range of 10 hPa?300 hPa.