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I was wondering if it possible to construct a reliable burglar alarm, based on an volumetric air pressure sensor. It should measure changes in air pressure when door or window is opened. We have made some tests with an air pressure sensor, but unless the door is opened very fast, the signal is burried within the sensor noise. As our knowlegde of these types of systems are limited, we hoped someone here would know, if it even is possible. Which sensor ( part number) and circuit would be perferred for such a system?

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  • \$\begingroup\$ I've seen cheap electret microphones use for this purpose and they seemed to work (in principle). \$\endgroup\$ – Andy aka Nov 9 '13 at 18:30
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    \$\begingroup\$ Have a blower continually add or remove air from the secured area. Opening a door/window will drop the pressure difference and trigger an alarm. The sensor will need to sample inside and outside of the secured area. \$\endgroup\$ – Optionparty Nov 9 '13 at 19:02
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    \$\begingroup\$ Tell us what your calculated change in pressure is. e.g., It's a calm day the outside air pressure is 1,000 mbar and the inside pressure is 1,000 mbar. Someone opens the window. What do you expect to happen? Or is the house at a different pressure to the outside? When you calculate the change in pressure then you can start to look for a suitable sensor. \$\endgroup\$ – Transistor Dec 6 '15 at 22:15
  • \$\begingroup\$ What do you mean by 'volumetric air sensor'? \$\endgroup\$ – Transistor Dec 6 '15 at 22:16
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Here's a sensor that might work for you - it's quite sensitive. MS5611

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This has very high resolution (and accuracy) MPL3115A2

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