I always wondered how electronic sensors work. I mean, there is some kind of analogue sensor that detects a value that is not quantifiable (temperature, pressure, speed etc.). How exactly does conversion from analogue detector get transformed to some kind of numeric value that gets shown to user?
In: Engineering
It depends on what you’re sensing!
Temperature is usually sensed with a device called a thermocouple. Thermocouples use the thermoelectric effect – certain types of devices will create voltage when there’s a temperature difference between the two sides of the device. The amount of voltage they make is directly in proportion to how big the temperature difference is. So you can make a thermocouple and then calibrate it with known temperatures (like how you know an ice bath is 0° and you know boiling water is 100° at sea level,) and then you can hook your thermocouple up to a multimeter. The amount of voltage it makes tells you how hot of a temperature you’ve exposed it to.
Pressure is measured a few different ways. You can have a flexible membrane hooked up to a strain gauge – more pressure means it pushes harder on the membrane, which means more strain is measured by the strain gauge – and again that makes a signal that your multimeter or other detection software can read.
The basic gist to measure X digitally is find a device that will produce a varied current or voltage with respect to X, and connect it to something that can really precisely measure and record voltage. And then calibrate the device.
Latest Answers