Measurement effect
A measurement effect is a physical phenomenon that is used in a measurement . There are only a few cases in which the measured variable can be compared directly with a known value of this variable, for example by applying a scale. For the majority of the quantities to be measured, use must be made of a physical law that leads unambiguously and reversibly to another physical quantity that is easily accessible for measurement.
While in the early days of the development of measurement technology, phenomena that are visible and then readable were preferably used, now it is preferable to use phenomena that lead to an electrical signal .
- Example temperature measurement:
- First liquid glass thermometer , Galileo thermometer or bimetal thermometer ,
- now industrial resistance thermometers or thermocouples .
The advantage of the electrical signals is its ease of formability (in interference-robust analog or digital signals ), the easy portability to remote registration points ( display , logging) and is easy to valuate in automation tasks (such as control technology ).