ILPS22QS absolute pressure sensor is made for measuring pressure in industrial applications. We will go through parameters which make this sensor optimal for monitoring pressure in harsh environments and see a demonstration of utilization of this sensor for recognizing condition of an air filter in ventilation system. We will also provide list of resources for developing applications with this sensor.
1. Why is ILPS22QS optimal for industrial pressure measurements
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ILPS22QS is a dual full scale digital barometer capable to measure pressure up to 4 bars in extended temperature range from -40 to +105 °C.
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ILPS22QS is housed in ultra-compact (2 x 2 x 0.73 mm) fully molded LGA package. Therefore, it is highly robust against dust and humidity.
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It has embedded electrostatic sensor called Qvar, which can be used for example for water leakage detection.
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ILPS22QS sensor is included in ST’s longevity commitment program assuring its supply for a minimum of 10 years.
2. Demonstration of air filter condition recognition with ILPS22QS
In this demonstration we can recognize condition of an air filter inside a ventilation system. The goal is to raise a warning when the filter is getting clogged.
In the figure below you can see a diagram depicting the demonstration. There is a transparent pipe with a fan mounted on the right side. The fan is sucking air out from the pipe. In the middle we have two shutters to simulate air filter, one shutter is fixed, and one is moving using a stepper motor. Finally, there are two ILPS22QS pressure sensor evaluation boards each on one side of the air filter. Actual pressures P1 and P2 measured by the two sensors are shown in real time on an LCD touch display together with indication of the state of the air filter.
The two ILPS22QS sensors are mounted on ST evaluation boards STEVAL-MKI228KA.
Let’s have a look how is the demonstration working.
In normal condition, when the filer is clean, pressure P1 before the filter and pressure P2 after the filter are almost the same.
When the filter is getting clogged the pressure P2 after the filter starts to drop.
Eventually the filter gets completely clogged.
Even if the difference between the two pressures in our demonstration is just around 50 Pascal it can be well detected by the application thanks to accuracy of the sensors.
With the two ILPS22QS sensors we can recognize condition of the air filter and give an early warning before the filter gets too dirty.
In this setup we can also detect an obstruction in the ventilation system as you can see in the picture below, where we have closed the pipe on the left side with a plate.
3. Resources
- Video of this demonstration
- ILPS22QS product page with datasheet, application notes and other documentation
- STEVAL-MKI228KA pressure sensor evaluation kit with Qvar functionality based on ILPS22QS
- Low level drivers
In ST we have a complete family of pressure sensors designed for many different consumer and industrial applications. For more information, please contact your ST local representative or visit our website st.com/pressure.