Existing sensors, such as those based on simple pressure switches and motor resistance, are limited in their ability to detect subtle changes in pressure and to distinguish between different textures. (newscientist.com)
External leaks are typically found by simple pressure... (yourmechanic.com)
If you are looking for childproofing gates to secure stairways make sure that they are installed gates and not simple pressure mounted ones. (childproofingtips.com)