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NOVA AYU RAHMADYA. ABSENT NUMBER: 16 CLASS: 7C. ADVANTAGE and DISADVANTAGE. Advantage of alcohol thermometer : * It can measure a low temperature, because it freezing point is low. * It can measure the temperature precisely, because it has large expansion coefficient.
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NOVA AYU RAHMADYA ABSENT NUMBER: 16 CLASS: 7C
ADVANTAGE and DISADVANTAGE Advantage of alcohol thermometer : * It can measure a low temperature, because it freezing point is low. * It can measure the temperature precisely, because it has large expansion coefficient. * It expansion is regular.
Disadvantage of alcohol thermometer : • It cannot measure a high temperature , because its boiling point. • It makes wet the wall of its place. • It is colourless so it must be given dyestuff in order to be visible.
Advantage of mercury thermometer : # It is visible, because its colour is silvery shining. # Its expansion is regular. # It does not make wet the wall of its place # It can measure a high temperature, because its boiling point is high # It can measure the temperature quickly and precisely.
Disadvantage of mercury thermometer: • It cannot measure very low temperature, because its freezing point is high. • Mercury is poisonous, so it is harmful if its tube is broken. • Its price is very high.
ALCOHOL THERMOMETER • the contents of an alcohol thermometer are less toxic and will evaporate away fairly quickly • The liquid used can be pure ethanol or toluene or kerosene depending on manufacturer and working temperature range
Beckmann thermometer • used to measure small differences of temperature, but not absolute temperature values • thermometer's length is usually 40 – 50 cm • The temperature scale typically covers about 5 oC and it is divided into hundredths of a degree
INFRARED THERMOMETER • measure temperature using blackbody radiation (generally infrared) emitted from objects. • They are sometimes called laser thermometers • The most basic design consists of a lens to focus the infrared energy on to a detector, which converts the energy to an electrical signal
GALILEO THERMOMETER • made of a sealed glasscylinder containing a clear liquid and a series of objects whose densities are designed to sink in this sequence • The temperature is typically read from an engraved metal disc on each bulb • The Galileo thermometer works due to the principle of buoyancy