The Evolution of the Thermometer

The German Theodore Hannes Benzinger invented the first ear thermometer with Englishman David Phillips inventing the first infra-red ear thermometer in 1984. Thermometers are used to detect or measure changes in temperature. Thermometers can be found almost anywhere. In the home, the oven thermometer keeps the heat for cooking at a set temperature. In the fridge the thermometer keeps the cold temperature at a selected level. In heating appliances as well the thermometer monitors designated set temperatures. And of course in the medical profession thermometers are used to check the temperatures of patients.

To understand the concept and workings of a thermometer perhaps it is best to make you own simple thermometer at home and observe. To do this you will need a jam jar with a water tight lid, some plumbers putty and a drinking straw. First of all make a hole just big enough for the drinking straw to fit into in the lid of the jam jar. Insert the straw into the hole and seal around the straw in the hole to prevent any leakage. Next place the jar on a table and fill up to the brim with very cold water. When this has been done put the lid containing the straw back onto the jar. You may lose a little of the water when you do this but it is of no concern. OK so now we are ready for the main part of the experiment. Find yourself a saucepan and fill it a little with very warm or hot water. Now place the jam jar with the very cold water into the saucepan. What you will see next is the water in the jam jar rising up the straw. This is because of the water changing temperature influenced by the warm water in the saucepan. The water in the jar will expand and rise more up the straw the warmer it becomes. So now you see the basic workings of a thermometer. So as the water rises up the straw it shows how much warmer it is becoming. Of course to need some numerical scale to show exactly how warmer the water is becoming. If you want to go further with your experiment or you are doing this with children you can devise you own measuring scale.

Today thermometers use the readings of Celsius and Fahrenheit. In devising their own particular scales, Fahrenheit decided that the boiling and freezing points of water would be separated by 180 degrees, whilst Celsius decided upon separating the two by 100 degrees. Celsius is the most used now in scientific issues and the majority of educational purposes.

Thermometers have evolved considerably over the centuries to today’s day and age where they have become digital and very easy to the use. The ear thermometer is a perfect tool for any parent with young children to own. They give a very accurate temperature reading within seconds of being placed in the ear. The eardrum shares its blood supply with the temperature control centre of the brain. So it’s a logical progression to proceed and devise methods of reading body temperatures from the ear.

For those of you that do not already own one of these devices, it is highly recommended that you go out and purchase one. A very useful implement to have in the household and makes the task of taking body temperatures very easy and accessible.



Source by Hans Erik Ostman

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