1. Hold the thermometer by its upper end to prevent body heat from affecting the expansion or contraction of the liquid inside. Ensure the entire glass bulb is immersed in the liquid being measured, taking care not to touch the bottom or sides of the container. If the bulb contacts the container, the reading will not accurately reflect the temperature of the liquid.
2. After submerging the thermometer bulb in the liquid, wait briefly for the reading to stabilize before taking it. Reading before the liquid column stops rising or falling will not reflect the true temperature of the water.
3. Keep the thermometer bulb submerged in the liquid while reading the temperature. Removing it from the liquid will result in an inaccurate reading. Align your line of sight with the upper surface of the liquid column. Failure to do so may cause readings to be too high or too low.
Never shake the thermometer before taking a reading.
When temporarily measuring indoor or outdoor temperatures, hold the thermometer by its upper end. Wait until the liquid column stops moving before reading the temperature. When reading, ensure your line of sight is level with the top of the liquid column. For long-term outdoor temperature monitoring, hang the thermometer in a shaded, well-ventilated location.
For clinical thermometers, shake the thermometer before use to ensure the reading is below 35°C. Then, place the thermometer precisely in the center of the armpit (underarm temperature is typically measured) for at least 5 minutes. Remove the thermometer, turn it sideways, and read the temperature aligned with the red mark.
Precautions for Thermometer Use
Thermometers vary widely based on the measuring substance and temperature range. For everyday use, the most familiar and common type is the body thermometer. What should you be mindful of when using it?
For oral temperature measurement, shake the thermometer to below 35°C before use.Place the thermometer under the tongue and measure for at least 3-5 minutes. For a mercury thermometer, 2 minutes is sufficient. Remove the thermometer, read the temperature, wipe it clean with tissue paper, then disinfect it with an alcohol swab (wipe from the tip toward the mercury end in a circular motion). After removing a mercury thermometer, wait 10 seconds before reading the temperature and discarding it.Note: Do not take oral temperatures from infants, individuals with breathing difficulties, those who are unconscious, those with a history of seizures, or uncooperative individuals. Wait 30 minutes after eating, drinking hot beverages, smoking, chewing gum, strenuous exercise, emotional agitation, or bathing before taking a temperature. When handling a mercury thermometer, hold it by the end and avoid touching the sensing tip.
For underarm measurements, shake the thermometer to reset the reading below 35°C before use. Place the thermometer at the top of the armpit, ensuring the mercury end is in tight contact with the skin and held firmly to prevent slipping or dropping. After 5-10 minutes, remove the thermometer, read the temperature, and wipe it with tissue paper.Similarly, ensure the armpit is dry before measurement if sweaty. If the thermometer is removed before the full measurement time, the reading must be repeated with the timer restarted. Wait at least 30 minutes after drinking hot beverages, strenuous exercise, emotional excitement, or bathing before taking a temperature.
For thermometers used in experiments, carefully read the instruction manual to confirm the measurement range of the specific thermometer. Not all thermometers are suitable for every application. Paying attention to operational details is essential for obtaining accurate readings.
Additionally, if the thermometer contains mercury, handle it with extreme care. If it breaks, do not touch the mercury with your hands, as it is toxic.