Temperature
Temperature
HEAT is a form of energy that goes from a region of high temperature to a region of low temperature. When a cold object is placed in a warm area, it will pick up heat from the surroundings. The cold object will get hotter and melt. When a warm object is placed in a cold area, heat from the object will go out into the surrounding area. The warm object will get cooler.
TEMPERATURE is how hot or cold an object is. There are three different scales of temperature:
(1) Kelvin (oK)
(2) Celsius (oC)
(3) Fahrenheit (oF)
The THERMOMETER is used to measure temperature. There is a liquid inside the thermometer. The liquid can be mercury or coloured alcohol. When the thermometer is placed in or on a hot object, the liquid expands and rises. When the thermometer is placed in or on a cold object, the liquid contracts and falls.
There are three types of thermometer:
(1) Laboratory
(2) Clinical
(3) Maximum/ Minimum
Laboratory Thermometer – used for general purposes (not to check body temperature). It contains mercury or coloured alcohol. It usually ranges from -10oC to 110oC. The scale is usually in 10o divisions. The temperature of the object must be recorded while the thermometer is still in or on the object.
Clinical Thermometer – used to measure body temperature. It contains mercury. It usually ranges from 35oC to 42oC. This thermometer has a narrow constriction. This prevents the liquid from going back to normal as soon as the thermometer is removed from the body.
Maximum/ Minimum Thermometer – used to record the maximum and minimum temperatures over a 24 hour period. It contains both mercury and coloured alcohol. When the alcohol gets hot and expands, it pushes the mercury around a tube that is shaped like a ‘U’.