A thermometer is an instrument that is used to take the temperature readings of the atmosphere or of a system. The control and monitoring of various processes in the industries is essential to boost the productivity. The records of the temperature are also used in further analysis of the industrial processes. The Qualitywell thermometers are the ones that are commonly used in the industries mainly because they are durable and reliable. These thermometers are available in different types. You choose Qualitywell thermometers based on the industrial applications that you are carrying out. The liquid-in-glass thermometers are the most popular type. They work on the basis that liquids will expand when heated and contract on cooling. These thermometers are made of glass tubes with small bulbs at the bottom that contain the liquid. Mercury and alcohol are the two most commonly used liquids in these thermometers. They can be used to measure body temperatures. When the instrument comes into contact with the body the liquid inside the bulb heats up and starts to expand. The liquid climbs up the gauge and halts at a certain point, which indicates the temperature of the body. The bi-metal thermometer is another type thermometer that uses two metal strips. The metals that are used expand at different rates when the temperature is increased. They are fused together. When exposed to temperature changes then the metal strip bends to indicate an equivalent of the temperature change on a scale. The electrical thermometers are categorized into thermocouple and resistances thermometers. The thermocouple thermometer works on the principle that the resistance of a material is directly proportional to its temperature. The resistance thermometer operates using two metals; one of the metals remains in the ice whereas the other one is connected to the system whose temperature is to be measures. The thermocouple converts the heat into electric energy that produces a voltage that varies with the temperature. The gas thermometers utilize hydrogen, helium or nitrogen. These Qualitywell thermometers are categorized into constant pressure thermometers and constant volume thermometers. The technology that is used works on the principle that the gases expand when they are subjected to an increase in temperature. The temperature will be determined by measuring the change in volume of the gas. There are numerous Qualitywell thermometers that you can use. The one that you select should be designed for the type of system that you want to measure for accurate readings.