< > [Metrology](index.html)
## Force and Pressure
### [Pressure](https://www.sensorsmag.com/components/pressure-measurement-principles-and-practice)
Pressure = Force / Area
[Pressure measurements](https://www.digikey.com/en/articles/techzone/2011/nov/what-you-need-to-know-about-pressure-sensors)
<blockquote>"Force collector electronic pressure sensors typically use a force collector (diaphragm, bourdon tube, bellows, etc.) to measure strain due to pressure or force over a given area. They include piezoresistive strain gauges, capacitive, electromagnetic, piezoelectric, optical, and potentiometric sensors."</blockquote>
#### [capacitive sensors](https://www.designworldonline.com/capacitive-sensors-measure-low-forces/)
[Easy to DIY](http://fab.cba.mit.edu/classes/863.12/people/calisch/9/week9.html)
[Parallel plates](http://fab.cba.mit.edu/classes/862.16/people/sam.calisch/project/index.html)
#### magnetic
[1 to 6 dof](https://gitlab.cba.mit.edu/calischs/loadcell)
#### Thermal pressure sensing
this is your analogue barometer
#### [Load cell](https://www.omega.com/prodinfo/loadcells.html)
This is what's in an [Instron](http://fab.cba.mit.edu/content/tools/instron/index.html)
#### [Strain gauge](https://www.omega.com/guides/straingages.html)
[How to use with weatstone bridge](http://www.ni.com/white-paper/3642/en/)
#### Wire-less pressure sensors:
<ul>
<li>[RFID](https://patents.google.com/patent/US9305252B1/en?oq=Patent+No:+9305252;+978587)</li>
<li>[Surface acoustic wave (SAW)](http://www.mas.bg.ac.rs/_media/istrazivanje/fme/vol38/1/02_mfhribsek.pdf)
<blockquote cite="http://iopscience.iop.org/article/10.1088/1674-4926/37/2/021001/pdf">"Surface acoustic wave (SAW) devices have been widely used in different fields and will continue to be of great importance in the foreseeable future. These devices are compact, cost efficient, easy to fabricate, and have a high performance, among other advantages. SAW devices can work as filters, signal processing units, sensors and actuators. They can even work without batteries and operate under harsh environments... [Applications include] temperature sensors, pressure sensors, humidity sensors and biosensors."</site></blockquote></li>
<li>[electromagnetic transduction](https://pdfs.semanticscholar.org/ae1c/3d85bfb12633d36869c86d08901bbafb6ef2.pdf)</li>
</ul>
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