Frequently Asked Questions (FAQ)

Question: What is an absolute pressure sensor?

Answer: Absolute pressure sensors measure the applied pressure in comparison to the absolute vacuum.

Question: What is a relative pressure sensor?

Answer: Relative pressure sensors measure the difference between the ambient pressure and the measuring pressure.

Question: What is a barometric pressure sensor?

Answer: Barometric pressure sensors measure the air-pressure comparative to the vacuum.

Question: What is a differential pressure sensor?

Answer: Differential pressure sensors measure the difference between two measuring pressures.
For more detailed information please read the application note: aan505.pdf.

Question: What is a bidirectional difference pressure sensor?

Answer: Bidirectional Difference Pressure Sensors measure the difference between two measuring pressures, in doing so it doesn’t matter which pressure is higher or lower. In this way low and high-pressure can be measured comparative to a given pressure.
Links: Article aan505, Article aan506, Article aan510

Question: What is a ratiometric sensor?

Answer: A ratiometric sensor is a sensor whose output signal changes synchronously with the changing of the supply voltage.

Question: How do you protect silicon sensors against liquids?

Answer: Pressure sensors with silicon measuring cells are sensitive to liquids and a multitude of aggressive substances. The article describes which arrangements can be made to reduce the feared media sensitivity of relative- respectively difference pressure sensors dramatically.
Link: Article aan508

Question: How do you calibrate ceramic measuring cells?

Answer: This article describes in detail a simple electronic circuit based on a suitable IC and few external components to amplify and to calibrate the offset- and full span-signal of ceramic sensing elements. The aim is to create a ready-to-mount sensor system with a ratiometric output signal and a suitable level of precision without a temperature compensation.
Link: Article aan504.pdf

Question: What is a pressure sensor module?

Answer: Pressure sensor modules are pressure sensors, whose output signals have to be calculated by an external microprocessor.

Question: How do you measure the level of liquids with a pressure sensor?

Answer: How to measure the hydrostatic pressure by using a pressure sensor is described on the application note aan506.

More answers on technical questions concerning the sensors of MEAS can be found on the website of MEAS INC.