What properties explain the behavior of liquid-filled thermometers?

Answer 1

a liquid filled thermometer reacts to the temperature it is subject to; by the liquid increasing in pressure and expanding , which results in movement of the liquid /"medium" that is used to fill it ; in most cases ;; Mercury substance .

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note , whilst the most common type of device used is the mercury in glass thermometer which is used in science laboratories .

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but be aware that there are other types used; but in industrial applications.

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1 type used in a engineering role ; is mercury in steel type of thermometer detector .

this is a measuring device which has a steel sensor device ; maybe about 2 inches 50 . mm . length , and this is joined to a steel capillary tube which has some degree of flexibility , and will have a long length until it is connected to the measuring scale .

the capillary tube has a hollow interior , which allows the mercury fluid to move within when subject to heat / and expand .

the increase in pressure is effected to another device called the measuring pressure tube .

the tube is commonly known as a bourdon tube pressure gauge .

and once again the capillary tube will be connected physically to the gauge tube .

the increase in mercury pressure , will cause the fluid substance to expand and move upwards in the capillary tube to the bourdon tube in the gauge .

this action causes the bourdon tube to move by deflection , in an arc because the tube is tensile, and causes itself to move outward and this small movement , is transmitted by a small brass gear mechanism linkage to a central pointer system , which when moved and effected appears to move across a scale which consequently indicates a value on a scale .

and the operator can read off a value from the measuring scale .

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so the properties of a liquid filled thermometer are ;

it should have a safe method of being sealed fully across its structure body between the measuring sensing device to the measuring scale .

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this is because the accuracy of measuring system depends on the sealing .

and because the interior will contain a substance which is harmful to health .,

and the repeatability of measuring accuracy depends on safe

e sealing of pressure whithin the system,