Temperature measurement is very crucial in a wide range of industrial applications, so continuous temperature measurement is highly significant. Temperature can be measured with various sorts of sensors; which all work according to a similar principle of temperature output as per the changes whatsoever caused by their physical properties. According to the type of application, this can be divided into the following parts.
Contact Method
This particular method is used when the body and the sensor remain in contact with each other. 3 different thermometers are used in the contact method, as follows:
- Expansion thermometers: They use bimetallic devices that have 2 different materials. So, these devices have strips of 2 metals, bonded together. When heated, one side expands more than the other, so the resulting expansion is converted into a temperature reading by a mechanical connection to a pointer. The advantage is that they are portable and do not require a power source. And the disadvantage of these types of instruments is that they are not as accurate as other devices and cannot be used for direct control or recording.
- Filling system thermometers: They are filled with any substitute. They generally fall into 2 main categories: mercury type and organic liquid. Because mercury is considered an environmental hazard, regulations apply to the transportation of equipment containing mercury. Today, there are filled system thermometers that use gas instead of liquids. The advantage of such devices is that they do not require electricity, do not present an explosion hazard, and are stable even after repeated cycling. And the disadvantage of these types of devices is that they do not produce data that can be easily stored or transmitted, and they do not make point or point measurements.
- Electric thermometers: As its name proposes, this type of instrument detects temperature through electrical quantities (like the voltage, & resistance, etc.). So, we can say that this won’t be controlling indicator thermometers, for instance, mercury in glassware. In most industrial & laboratory processes, the measuring point is usually far from the indicator or control device. This may be due to necessity (like in an adverse environment) or convenience (as in centralized data collection). Devices that convert temperature into another signal, usually electrical quantities, are necessary. The most common devices in this type of thermometer are as follows:
- Thermocouples : They consist primarily of a thermocouple & a suitable two-wire extension lead, working based on a junction in the process, creating a small voltage that increases with temperature. It is done on a relatively stable & repeatable basis.
- Resistance thermometers : This makes use of a precision resistor whose resistance value (ohms) increases with temperature. The RTD had a positive temperature coefficient. Such sort of variation(s) is quite stable & indeed repeatable.
- Thermistors (the similarity is that they all require) : This is a semiconductor used as a temperature sensor. It is made from a mixture of metal oxides pressed into a bead, disc, or other shapes. The pearl is heated under pressure at a high temperature and then encapsulated in epoxy or glass. Beads can be very small, in some cases less than 1 mm.
Non-Contact Method
This method is used if the body and the sensor are not allowed to contact each other. The most common non-contact thermometers are the easy-to-be-operated infrared sensor & pyrometer, which is now the most common non-contact temperature measuring instrument in industrial applications!
Heatcon Sensors
If you’re looking for accurate temperature measurement, you can’t go wrong with Heatcon Sensors. These sensors use the latest in heat-sensing technology to provide reliable readings. Whether you’re measuring the temperature of a room, an object, or even the air, Heatcon sensors are up to the task.
