How They Work

Mercury-in-glass thermometers consist of a glass tube filled with mercury. The mercury expands and rises in the tube as the temperature increases, and contracts and falls as the temperature decreases. The temperature is read by noting the level of mercury against a calibrated scale on the tube.

Practical Uses

• Medical: Used to measure body temperature.

• Laboratory: Commonly used in scientific experiments due to their accuracy.

• Weather: Used in meteorology to measure atmospheric temperatures.

How to Use

• For medical use, place the bulb under the tongue, in the armpit, or rectally.

• Ensure the thermometer is clean before and after use.

• Read the temperature at eye level.

How They Work

Digital thermometers use electronic sensors to measure temperature. They often provide a digital readout on a screen, making them easy to use and read.

Practical Uses

• Medical: Widely used for measuring body temperature orally, rectally, or axillary (underarm).

• Home and Kitchen: Used to measure food and liquid temperatures.

• Industrial: Used in various applications requiring quick and accurate temperature readings.

How to Use

• For body temperature, place the probe in the desired location (mouth, armpit, rectum).

• Turn on the thermometer and wait for the beep indicating the reading is complete.

• Read the temperature on the digital display.

How They Work

Infrared thermometers measure temperature from a distance by detecting the infrared radiation emitted by an object. They provide a quick, non-contact temperature reading.

Practical Uses

• Medical: Used to measure body temperature, particularly on the forehead or in the ear.

• Industrial: Used to measure the temperature of machinery, electrical components, and other surfaces.

• Food Safety: Used in kitchens to measure the surface temperature of food.

How to Use

• Point the IR thermometer at the object or surface.

• Ensure the thermometer is at the recommended distance from the target.

• Press the trigger and read the temperature on the display.

How They Work

Bimetallic strip thermometers consist of two different metals bonded together, which expand at different rates when heated. This causes the strip to bend, and the movement is translated into a temperature reading on a dial.

Practical Uses

• Industrial: Used in HVAC systems, ovens, and other machinery to monitor temperatures.

• Home: Often used in thermostats and some kitchen appliances.

How to Use

• Place the thermometer in the environment or device where you want to measure the temperature.

• Read the temperature on the dial.

How They Work

Thermocouples consist of two different metals joined at one end. When the junction experiences a temperature change, it generates a voltage that can be measured and converted into a temperature reading.

Practical Uses

• Industrial: Used in a wide range of industrial processes, including furnaces, kilns, and engines.

• Scientific Research: Used in laboratories for precise temperature measurements.

How to Use

• Insert the thermocouple probe into the environment or material to be measured.

• Connect the thermocouple to a suitable measurement device to read the temperature.

How They Work

RTDs measure temperature by correlating the resistance of the RTD element with temperature. The resistance increases with temperature, and this change can be measured and converted into a temperature reading.

Practical Uses

• Industrial: Used in process control applications, power plants, and chemical plants.

• Scientific Research: Used for precise temperature measurements in experiments.

How to Use

• Insert the RTD probe into the environment or material to be measured.

• Connect the RTD to a suitable measurement device to read the temperature.

How They Work

Liquid crystal thermometers use heat-sensitive liquid crystals that change color at specific temperatures. They are often used in the form of strips or patches.

Practical Uses

• Medical: Used as fever strips to measure body temperature.

• Aquariums: Used to monitor water temperature.

• Home and Office: Used to measure room temperature.

How to Use

• Place the liquid crystal strip on the surface to be measured.

• Observe the color change and compare it with the reference scale to determine the temperature.