Centrifugal thermometer
A special alcohol or mercury thermometer for measuring the air temperature outdoors is called a centrifugal thermometer . It is moved in a circle on a string for a few seconds at head height.
The improved ventilation due to the high circular speed
- on the one hand increases the measurement accuracy through faster heat transfer,
- at the same time reduces the half-life of the correct reading ,
- and reduces disruptive influences from outside - in particular due to heat radiation from buildings or the sun .
By skilfully "spinning" the temperature can be measured with an accuracy of 0.2 ° C, which is 2 to 5 times more precise than with a well- hung thermometer.
Frequent applications are in astronomy and geodesy for measuring or controlling the temperature field or refraction , in laboratory technology and physics , as well as for the approximate calibration of inaccurate measuring devices such as cheap weather stations , room thermometers or simple bimetal strips, for example on outdoor thermometers .
See also: thermostat , Assmann psychrometer , measuring system