How does a liquid thermometer measure temperature?
A thermometer measures temperature through a glass tube sealed with mercury that expands or contracts as the temperature rises or falls. The tiny size of the bulb and micro-fine size of the tube help the mercury reach the temperature of what it is measuring very rapidly.
What is the liquid in a glass thermometer?
The liquid that is contained within the thermometer may be one of many different substances, but the most common are mercury, toluene (or a similar organic substance), and low-hazard biodegradable liquids.
How does mercury in glass thermometer work?
In a mercury thermometer, a glass tube is filled with mercury and a standard temperature scale is marked on the tube. With changes in temperature, the mercury expands and contracts, and the temperature can be read from the scale. Mercury thermometers can be used to determine body, liquid, and vapor temperature.
How does glass thermometer increase sensitivity of liquid?
Sensitivity of Thermometer. Using a thermometer with a smaller bulb – A smaller bulb contains less mercury and hence absorbs heat in shorter time. A glass bulb with thinner wall – Heat can be transferred to the bulb easily. Capillary with narrow bore – produces a greater change in the length of the mercury column.
Why does liquid in the thermometer rise when?
1. The liquid in the thermometer goes up when the thermometer is heated because heating makes the alcohol molecules of the liquid move faster. The extra speed of the molecules competes with their attraction for one another and causes them to move slightly further apart.
How is a glass thermometer read?
The long lines on the thermometer are one degree. Each little line is . 2 degrees. All glass thermometers are marked with an arrow which points to 98.6 (Considered to be the normal adult temperature).
What happens if you touch mercury?
MERCURY EXPOSURE If it is swallowed, like from a broken thermometer, it mostly passes through your body and very little is absorbed. If you touch it, a small amount may pass through your skin, but not usually enough to harm you.
How a liquid glass thermometer can be used to measure the body temperature of a sick person?
Operating principle A liquid in a glass tube (called a capillary) expands when heated and contracts when cooled. A calibrated scale can then be used to read off the respective temperature that led to the corresponding thermal expansion. Such thermometers are also called capillary thermometers.
What is the physical property that changes with temperature in a liquid in glass thermometer?
A thermometer has a liquid in a very narrow tube, which when heated will expand and move up the tube. If you cool the liquid down, then the liquid will contract and move back down the tube. So the physical property used in a thermometer is thermal expansion.
Why do liquid thermometer goes up and down?
When heated, the molecules of the liquid in the thermometer move faster, causing them to get a little further apart. This results in movement up the thermometer. When cooled, the molecules of the liquid in the thermometer move slower, causing them to get a little closer together.
Why does the liquid rise and fall in the tube of a glass thermometer?
The fluid/glass thermometer is the most popular thermometer used around the world to measure body temperature. It consists of a sealed glass tube with a small internal diameter (like a lumen) connected to a reservoir. Increasing the temperature expands and pushes up the fluid in the reservoir and tube.