Table of Contents
How does a mercury or alcohol thermometer indicate temperature?
A thermometer has a glass tube sealed at both ends and is partly filled with a liquid like mercury or alcohol. As the temperature around the thermometer’s bulb heats up, the liquid rises in the glass tube. The temperature is written in numbers with the (degree) sign.
Why is alcohol used in thermometers instead of mercury?
Alcohol thermometers are used rather than mercury thermometers in very cold regions because alcohol has a lower freezing point than mercury. If it freezes it won’t move in the tube, so a liquid must be used that has a freezing point that’s lower than the temperature it’s measuring.
How long do you keep a mercury thermometer in your mouth?
3 minutes
Mouth: Place the probe under the tongue and close the mouth. Breathe through the nose. Use the lips to hold the thermometer tightly in place. Leave the thermometer in the mouth for 3 minutes or until the device beeps.
How long do you keep a mercury thermometer under your tongue?
ORAL TEMPERATURE After shaking the mercury down, place the thermometer under the child’s tongue, with the bulb toward the back of the mouth. Tell your child to keep the lips firmly closed, but not to bite the thermometer. 3. Leave the thermometer in place for 3 minutes.
What’s the difference between a mercury and an alcohol thermometer?
Alcohol Thermometers: Alcohol thermometer is suitable for measurement of low temperatures. Mercury Thermometers: Mercury thermometer is suitable for measurement of high temperatures. Alcohol Thermometers: Alcohol thermometers are used to measure temperatures from -115°C to78.5°C.
What happens when you replace mercury with alcohol?
But alcohol has a coefficient of thermal volume expansion about 5.5 time that of mercury. This means that if one were to take a mercury thermometer and replace the mercury with alcohol, a given temperature change would result in 5.5 times as much motion of the fluid in the capillary.
What kind of dye is used to color alcohol thermometers?
The alcohol present in the alcohol thermometers is colored using a dye, usually containing blue or red color; however, the mercury present in the mercury thermometers already has a natural silver color, so it does not need any dye to color.
How does alcohol affect the sensitivity of a thermometer?
The thermal conductivity and specific heat of the working fluid in a thermometer do not affect the sensitivity of the thermometer; only the speed of response, and possibly the effect of the thermometer on the system being measured. But alcohol has a coefficient of thermal volume expansion about 5.5 time that of mercury.