A thermometer is a device that measures temperature or a temperature gradient. The word thermometer comes from the Greek words therme, meaning heat, and metron. There are three main types of thermometers: liquid-in-glass thermometers, bimetallic strip thermometers and electronic thermometers.
Modern techniques to measure thermometer are with the help of thermistors, Thermocouples, Resistance Temperature Detectors (RTDs), and Semiconductor Temperature Sensors. The thermometer can measure a wide range of temperatures from -200°C to +1200°C. On the other hand, the barometer is limited to measuring atmospheric pressure in the range of 600 millibars to 1,200 millibars.
More details about make up of a thermometer.
The barometer is used to measure atmospheric pressure. It can be used to predict short-term changes in the weather. If the pressure is falling, it means that bad weather is on its way. If the pressure is rising, it means that the weather is improving and sunshine is on its way.
Key Difference Explained
Thermometer is to record the temperature and barometer is to assess the atmospheric pressure.
The thermometer measures temperature by sensing a change in the expansion of a liquid or gas. The barometer measures atmospheric pressure by sensing a change in the weight of a column of mercury.
The thermometer is more commonly used than the barometer because temperature is a more important meteorological parameter than atmospheric pressure.
Many gadgets have thermometer and barometer 2 in 1 options in which you can use both at the same time like for your pets or plants. The thermometer is used to measure the temperature of your surroundings while the barometer is there to help you check the atmospheric pressure for that day.