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Min Max Thermometer

Written by Nicholas Kamuda
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Traditionally, taking temperature readings often involved using a Vee Gee min max thermometer. Nowadays, digital technology allows more accurate temperature data to be recorded than what was possible with older, mercury-based thermometers. As a key component in home weather stations, digital thermometers are useful for a variety of applications around the house.

The Workings of Traditional Min Max Thermometers

Vee Gee min max thermometers operate on simple principles of buoyancy, magnetism and mercury flow. The tube of mercury is bent into a U shape, with the bulb at the end of the left arm. The mercury flows freely in the U-shaped tube, crawling up the left arm of the U (towards the bulb) as the temperature drops. As the mercury moves, it pushes a tiny steel marker up with it.

The steel marker records the minimum temperature until reset. If the temperature then rises, the mercury moves back down the left arm of the tube and up the right, but the steel marker stays in place thanks to the presence of a magnet. As the temperature rises, another steel marker is pushed upwards, recording the maximum temperature.

Digital wireless thermometers have replaced analog thermometers in current models of weather station. Digital technology allows more precise temperature measurements to be recorded and stored. Most weather stations are able to record a week's worth of weather data, or more if connected to a PC or home computer.


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