Table of Contents
How does a thermometer tell the temperature? A thermometer measures temperature through a glass tube sealed with mercury that expands or contracts as the temperature rises or falls. As temperatures rise, the mercury-filled bulb expands into the capillary tube. Its rate of expansion is calibrated on the glass scale.
How does a thermometer work chemistry?
The way a thermometer works is an example of heating and cooling a liquid. When heated, the molecules of the liquid in the thermometer move faster, causing them to get a little further apart. When cooled, the molecules of the liquid in the thermometer move slower, causing them to get a little closer together.
How a thermometer is used to make measurements?
Liquid-filled thermometers have been used for centuries to measure temperature. They consist of a liquid-filled reservoir at the end of a narrow tube. If the temperature of the liquid in the reservoir increases, it expands and rises into the narrow tube.
Why does liquid in the thermometer?
The liquid in the thermometer goes up when the thermometer is heated because heating makes the alcohol molecules of the liquid move faster. Since the molecules move further apart, the same amount of alcohol takes up more room in the thin tube of the thermometer. The liquid has nowhere else to go but up.
Can a thermometer measure heat?
Despite its name, however, a thermometer does not actually record heat, but rather temperature. Temperature and heat are two radically different concepts. Temperature is a measure of the average kinetic energy of the molecules within a substance.
How do you manufacture a thermometer?
The Manufacturing Process 1 First, the raw glass material is received from an outside manufacturer. 2 The bulb reservoir is formed by heating one end of the glass tube, pinching it closed, and using glassblowing and the application of an air-driven torch to complete it.
What is thermometer short answer?
A thermometer is a tool that measures temperature — how hot or cold something is. Made up of thermo (heat) and meter (measuring device), the meaning of the word thermometer is pretty straightforward. Thermometers measure temperatures in degrees, according to either the Celsius or Fahrenheit system.
What is the red stuff in a thermometer?
Mercury is a silver-white to gray substance. If your thermometer is filled with a red liquid, your thermometer contains red dyed alcohol or mineral spirits and not mercury.
What happens if you touch mercury?
Mercury is a very toxic or poisonous substance that people can be exposed to in several ways. 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.
Is there still mercury in thermometers?
The oldest thermometers used are mercury in glass. Newer thermometers include non-mercury liquids in glass and digital and electronic devices that use sensors to measure temperature. Thermometers that check body temperature in the ear, across the forehead, or have a digital display do not contain mercury.
What happen if you put the thermometer in salted ice?
Salt Lowers the Temperature of Ice Water. When you add salt to ice (which always has an outer film of water, so it’s technically ice water), the temperature can drop from freezing or 0 °C to as low as -21 °C. That’s a big difference! Salt lowers the freezing point of water via freezing point depression.
How does a digital thermometer work?
Digital thermometers work by using heat sensors that determine body temperature. They can be used to take temperature readings in the mouth, rectum, or armpit. When assessing digital thermometer readings, keep in mind that armpit (axillary) temperature runs about ½ to 1°F (0.6°C) cooler than oral readings.
What is the absolute zero temperature?
absolute zero, temperature at which a thermodynamic system has the lowest energy. It corresponds to −273.15 °C on the Celsius temperature scale and to −459.67 °F on the Fahrenheit temperature scale.
How do you check a temperature without a thermometer?
Checking for a fever without a thermometer Touching the forehead. Touching a person’s forehead with the back of the hand is a common method of telling whether or not they have a fever. Pinching the hand. Looking for flushing in the cheeks. Checking urine color. Looking for other symptoms.
How do you make a simple thermometer?
STEP 1: Add red food coloring, 1/4 cup water, 1/4 cup alcohol and a tablespoon of oil into a mason jar and mix. STEP 2: Stick the straw through the straw hole and tighten the lid onto the jar. STEP 3: Mold a piece of playdough on the lid around the straw, which will hold the straw about 1/2” from the bottom of the jar.
What metal is in a thermometer?
Mercury is the only one in liquid state at room temperature. It’s used in thermometers because it has high coefficient of expansion. Hence, the slightest change in temperature is notable when it’s used in a thermometer. It also has a high boiling point which makes it very suitable to measure higher temperatures.
How is a digital thermometer made?
Digital thermometers contain a small computing mechanism and a resistor. The computer converts the difference in resistance into a difference in temperature and offers a digital readout in degrees. The thermoresistor sensor is called a thermistor.
What material is used in thermometer?
Mercury is one of the most familiar materials used in liquid thermometers. Other liquids, such as kerosene or ethanol, may also be used in these types of thermometers.
What are the 4 types of thermometer?
There are different types, but not all thermometers are right for your child. Digital thermometers. Ear (or tympanic) thermometers. Infared thermometers. Strip-type thermometers. Mercury thermometers.
Who discovered thermometer?
The more modern thermometer was invented in 1709 by Daniel Fahrenheit. It was an enclosed glass tube that had a numerical scale, called the Fahrenheit scale. The early version of this thermometer contained alcohol and in 1714 Fahrenheit developed a mercury thermometer using the same scale.
