Introduction to laboratory thermometer

Both laboratory and clinical thermometers are used to measure whether a substance is hot or cold.

Introduction to laboratory thermometer


Laboratory and clinical thermometers are essential in testing hypotheses, saving lives, and other methods that support life skills. In addition, these devices are subject to standardization and calibration evaluation


A thermometer is a device that enables us to measure the temperature of objects, people, animals, materials, food, and the environment. We have different types of thermometers for each type of measurement we need to make. In thermometers we can also find different formats: mainly analog and digital


When cooking food, in laboratory experiments or in any other situation that requires accurate knowledge of temperature, we cannot use traditional thermometers to measure the temperature of food, but we must use laboratory thermometers. Laboratory thermometers are mostly digital.


Laboratory thermometers, despite their name, may suggest that they are special objects far from reality.

Analog thermometers: These types of thermometers give us the same design as traditional mercury/gallium thermometers.


An analog thermometer looks like a long glass tube with a bulb at one end, the material that allows us to measure temperature changes depending on the temperature of the object we are measuring.


Although most of the laboratory thermometers we can find in Europe give us measurements in Celsius, some also combine the Fahrenheit and Kelvin scales.


The digital thermometer is different from the digital thermometer that is used to measure body temperature, it is smaller and square, to connect the measurement sensor we need to fix it square. These thermometers have a screen that can display the temperature in a pre-set scale: Celsius, Fahrenheit or Kelvin.


Laboratory thermometer parts


The analog laboratory thermometer consists of a glass tube and displays the measurements we provide on the glass tube. Inside we find the capillary in which the liquid used for measurement circulates. Finally, we find the bulb, the bottom part of the thermometer, for measuring liquids


As the name suggests, a digital thermometer consists of a probe that can vary in length and we find sensors that can take measurements. This sensor sends an electrical signal to the central unit, which will interpret it to provide the data we want.


Unlike analog thermometers, digital thermometers are powered by a battery that should always be in good condition if we don’t want to make inaccurate measurements that could ruin a cooking project we’re already doing in the lab.


Laboratory thermometer accuracy


If you are looking for high-precision laboratory thermometers, digital thermometers are the most recommended, although due to their high costs, they have the potential to stand out, as long as we consider a quality model with certifications that guarantee correct operation and accurate measurements.


Such thermometers are always the fastest, but they are not recommended when we need to measure very hot or very cold objects, especially if the measuring cable is very short.


In this case, the best option is to choose a glass laboratory thermometer, which in most cases is more than 30 cm long, so we avoid the risk of hands getting close to the object being measured.


Calibration of laboratory thermometers


As I mentioned in the previous section, digital and analog laboratory thermometers are very accurate.

Getting the wrong temperature in a home experiment is not the same as getting the wrong temperature in an experiment, because if it’s wrong, the whole project can be ruined and have to start from scratch.


How to calibrate a thermometer


There are two methods for calibrating thermometers: the comparison method and the fixed point method


Comparative calibration involves comparing the reading of a calibratable thermometer with a reading of a thermometer of known characteristics.


Fixed Point Calibration Since ice melts at 0°C and freezes at the same temperature, use a fixed point temperature such as ice water for the fixed point calibration.