Temperature test measurement tools come in a wide array of sizes, shapes, and purposes. That said, they all have a single thing in common: they measure temperature by sensing some sort of change within a physical characteristic.
As it stands, there are quite a few different types of temperature test measurement tools. Knowing about a few of them can give you a better idea of which one might suit you best the next time you are looking to acquire the right tool.
Resistive Temperature Measuring Devices
One of the things you will notice quickly when you buy temperature measurement tools from a vendor like RS is the variety. Temperatures have become the kind of technology that runs the gamut in terms of intended use. Resistive temperature measuring devices are electrical, using resistance rather than voltage like a thermocouple might.
These devices increase in a positive direction, the resistance going up as the temperature does. Thermistors are the most common kind of resistive temperature measuring device, though thermistors are different in construction. They decrease in resistance as temperature rises. It is considered to be an extremely nonlinear semiconductive device.
Thermocouples, a voltage device that indicates temperature measurement through a change in voltage, is perhaps the most common type of temperature measurement tool. When temperature increases, the thermocouple’s output voltage will rise. That said, it may not be a linear rise.
The thermocouple tends to be located within some kind of ceramic or metal shielding, protecting it from exposure to potentially harsh environments of a wide variety. Metal-sheathed thermocouples also come with a number of different outer coatings available. Something like Teflon would help to stand up against strong caustic solutions like acid and any other potential elemental factors that could degrade and wear down the unit.
Another very popular type of temperature measurement tool, infrared sensors are ideal because they do not require physical contact to gauge a reading. Holding up an infrared sensor in front of the source will give you the temperature by reading the radiation of that surface. If you pointed it at a desk, for instance, you would probably get something that reads about room temperature.
There is a slight issue when it comes to using infrared sensors on liquids. For instance, if you pointed the sensor at ice water, then the temperature might come in slightly below 0C due to evaporation. That evaporation will slightly lower the overall expected temperature reading, creating some disparity in the process. Consider these factors if you plan on using infrared sensors for reading the temperature of liquids.
The one most people are likely to be familiar with. These are liquid expansion devices that can also be used for temperature measurements of various kinds. These are generally offered in two types: organic liquid (usually red) and mercury. There is a notable distinction between the two despite their similar uses. Mercury devices, for instance, have specific limitations on how they can be safely handled, shipped, and transported. Since Mercury is an environmental contaminant, it needs to be handled with additional care as breakage can wind up being hazardous.
Still, thermometers are going to be the most commonly available and best for around the house uses. Most people have a thermometer or two inside their home for two main purposes. The first is to read the temperature of food in order to ensure that it has been safely cooked. The other use is checking body temperature, whether through contact or infrared means. Thermometers can be found at regular stores and even some grocery stores as well.