Thermometer
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An instrument for measuring temperature. |
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It is usually made of a sealed glass tube, marked in degrees of Celsius or Fahrenheit. |
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It has a liquid, as mercury or alcohol. |
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The liquid rises or falls as it expands or contracts according to changes in temperature. |
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Some kinds of thermometers are clinical thermometer, digital thermometer, and electronic thermometer. |
Mercury thermometers
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A mercury thermometer is a glass tube with a bulb at one end that contains mercury. |
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A scale on the tube shows degrees of temperature, with an arrow marking the normal point of 98.6o F. |
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The bulb is placed under the tongue or in the armpit. |
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As the mercury is heated, it rises up the tube to a point that shows the person's temperature. |
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To read a thermometer, hold it at eye level in good light and rotate it slowly until you see the thin silver line of mercury. |
Oral temperature
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The most accurate reading is done with an oral temperature. |
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However, taking an oral temperature requires cooperation so do not attempt this method with young children or anyone who is not conscious and cooperative. |
Axillary temperature
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A regular thermometer can also be used under the arm. Authorities advise against taking temperatures rectally, even in children. |
Normal temperature
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Although 98.6o F is considered the "normal" oral temperature, a healthy person's temperature actually ranges from about 97o F to 99.5o F during a 24-hour period. Underarm temperature is 1o or 2o lower than oral readings. |
Never leave a child alone, even for a minute, with a mercury thermometer! Injury can occur from broken glass, and mercury is a poison.
Using a thermometer
Oral temperature
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First, clean the thermometer with soap and then rinse it with cool tap water. Hot water will cause the thermometer to break. |
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Hold the thermometer at the end opposite the mercury bulb and shake it a few times to make the mercury go below the arrow. |
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To take an oral temperature, place the bulb of the thermometer under the tongue as far toward the back as possible. |
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Have the person close his or her mouth and hold the thermometer in place for 4 to 5 minutes. |
Axillary temperature
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To take an underarm temperature, place the bulb of the thermometer snugly in an armpit and have the person keep the upper arm clasped tightly to the side, with the elbow bent and the lower arm folded across the chest. |
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Leave the thermometer in place for 10 minutes. |
After you're done, wash the thermometer again with soap and cool water and shake it to return the mercury to the bulb.