To select the right pressure sensor for a specific application besides the pressure range first of all the type of pressure measurement has to be considered. Pressure sensors measure a certain pressure in comparison to a reference pressure and can be divided into absolute, gage and differential devices. This report will explain these terms on the basis of First Sensor piezoresistive pressure sensors.
First Sensor LDE/LME differential pressure sensors measure ultra low air or gas pressures from 25 Pa (0.1 inH2O) full scale. The sensors are based on a new and innovative MEMS technology which integrates a micro flow channel within the silicon sensor chip.
First Sensor flow-based LDE/LME differential pressure sensors are experimentally compared in applications with dust-bearing air to other sensors which use the same sensing principle. Only the LDE/LME sensors kept their calibrated sensitivity over the entire duration of the tests.
First Sensor flow-based LDE/LME differential pressure sensors are experimentally compared in applications with high humidity to other sensors which use the same sensing principle. Only the LDE/LME sensors kept their calibrated sensitivity over the entire duration of the tests.
The digital HMI, HDI, HCLA, HCA and SSI pressure sensors are calibrated and temperature compensated with an on-board ASIC, which provides a corrected digital pressure value. For the HDI, HCLA, HCA and SSI series an additional analog voltage output is available at the same time.
The digital HME and HCE pressure sensors are calibrated and temperature compensated with an on-board ASIC, which provides a corrected digital pressure value. For the HCE series an additional analog voltage output is available at the same time.
First Sensor SSO series offers rugged OEM pressure sensors in a fully welded, media isolated stainless steel construction. These devices are temperature compensated from 0...50 °C when using constant current excitation. This application note describes the design of an appropriate constant current source.
The signal conditioning circuitry described below has been especially designed for First Sensor RCO series pressure sensors. However it can be applied to all sensors with a Common Mode voltage which is half of the supply voltage (VCM≈½ VS), e.g. First Sensor HDO series.
First Sensor oxygen sensors of the XYA series consist of two zirconium dioxide (ZrO2) discs coated with thin porous layers of platinum which serve as electrodes. The two discs are attached to a platinum ring, forming a hermetically sealed chamber.
If not using one of First Sensor ZBXYA interface boards for sensor control and conditioning of the XYA oxygen sensors, this appication note describes the basic building blocks required to create an interface circuit.
The performance and resolution of the CLC liquid level sensor basically depends on the application conditions such as the medium to be measured, vessel material and wall thickness, air gap between the sensor and the vessel and GND condition as well as changing electrical potentials in the vicinity of the sensor.
Due to their sensitivity and teaching possibilities First Sensor capacitive CLC and CLW sensors can be used to determine transition points between any two liquids with different densities and a sufficient difference in relative permittivity. A typical application is the detection of water accumulating at the bottom of an oil tank.
Mass flow is a dynamic mass per time unit measured in grams per minute (g/min). By referencing a volumetric flow (cm3/min) to its known temperature and pressure, an exact mass flow can be calculated. It is common in the industry to specify mass flow in terms of volumetric flow at standard (reference) conditions.