Foil Strain Gages: The Versatile Sensors
Foil strain gages are the primary sensors in many varieties of transducers; their versatility is unmatched in the sensor world. It is possible to measure weight, force, torque, acceleration, displacement, pressure, number of widgets in a box and even the growth rate of a tree -- all with the same strain gage type. The ability to weigh items from a few ounces to over 1M pounds is a common application.
Consider the steak you purchase at the market. You can witness the butcher weigh it on a strain-gage-based price-computing scale. Did you ever consider how many times strain gages were used prior to your steak purchase? When the calf is born it is weighed. As the calf grows it is weighed. The food used to feed the calf is weighed. The fertilizer used on the calf’s food source is weighed. The fertilizer coming from the cows themselves is weighed as it is applied to the fields. When the meat products are shipped to markets they are weighed on shipping scales. If you don’t finish your steak the leftover meat and maybe even your napkin will end up in a trash bin that is weighed when it is picked up. And finally, if you do eat all of your steak chances are you will weigh yourself on your bathroom or doctor’s office scale, and yes, these will almost certainly use foil strain gages.