What affects the sensitivity of a liquid in glass thermometer?
What affects the sensitivity of a liquid in glass thermometer?
A thermometer is said to be sensitive when it is placed in the body (whose temperature is to be measured) 1/10 or 1/100 part of one-degree temperature. For a small change of temperature more change in the height of the liquid column.
Which liquid is used for sensitive glass thermometer?
Mercury
The sensitivity depends on the reversible thermal expansion of the liquid compared to the glass. The greater the fluid expansion, the more sensitive the thermometer. Mercury was the liquid the most often used because of its good reaction time, repeatability, linear coefficient of expansion and large temperature range.
Why are glass thermometers not recommended?
Liquid in glass thermometers tend to be fragile and hence easily broken, can only be used where the liquid column is visible, cannot be used for surface temperature measurements, cannot be read from a distance and are unsuitable for high temperature measurements.
Is it safe to use a glass thermometer?
Though glass thermometers containing mercury may be more accurate than other kinds of thermometers, health professionals have recommended against their use once they recognized mercury as a risk.
What factors affect the sensitivity of a thermometer?
Some of the factors which increase sensitivity are:
- Using a thermometer with a smaller glass bulb, as a smaller bulb contains less liquid and therefore, absorbs heat in a shorter time.
- Using a narrow tube, as a small change in volume results in the liquid moving a larger distance along the tube.
How accurate is a liquid thermometer?
Organic-Liquid-Filled Glass Thermometers contain nonhazardous liquid in a graduated scale tube which closely resembles their mercury predecessors. The accuracy of a typical glass thermometer is ±1 scale division.
What is liquid-in-glass thermometer?
It consists of mercury as a liquid filled in a glass tube. On the body of the glass tube, calibrated marks are provided which facilitates the reading of temperature. A bulb is formed at one end of the thermometer which contains the largest part of mercury.
Which liquid is not used in liquid-in-glass thermometer?
Water is not able to be used as a thermometer liquid because of its higher freezing point and lower boiling point than the other liquids in general.
What is liquid in glass thermometer?
Are glass mercury thermometers safe?
The small silvery ball in a mercury thermometer can be dangerous if the glass breaks and the mercury is not cleaned up properly. The mercury will evaporate and can contaminate the surrounding air and become toxic to humans and wildlife.
How does volume of liquid affect sensitivity of thermometer?
Using a narrow tube, as a small change in volume results in the liquid moving a larger distance along the tube. Using a glass bulb with a thinner wall, as heat can be transferred to the bulb more easily and a small change in temperature can be more easily detected.
What makes a liquid in glass thermometer sensitive?
Under the following conditions, a liquid in glass thermometer becomes sensitive- For a small change of temperature more change in the height of the liquid column. The bulb should be of moderate size and the capillary tube should not be extremely narrow.
What makes a mercury thermometer more sensitive to temperature?
The sensitivity of a mercury thermometer can be increased by using a smaller mercury bulb, thinner wall and smaller bore. A smaller bulb contains less mercury and hence absorbs heat in a shorter time. As a result, it can respond faster to temperature change.
How is Mercury added to a glass thermometer?
A bulb is formed at one end of the thermometer which contains the largest part of mercury. The expansion and contraction of this mercury size is then further increased in the extremely thin bore of the glass tube. It aids in increasing the sensitivity of the thermometer.
Why does a glass thermometer respond faster to temperature change?
A smaller bulb contains less mercury and hence absorbs heat in a shorter time. As a result, it can respond faster to temperature change. A glass bulb with a thinner wall can transfer heat to the bulb easier. Therefore, the thermometer can respond quickly to small changes of temperature near the surrounding.
