Thermocouples are devices that measure the temperature of a system. These are made of two different metals, which are electrically connected together on one end with the other end open. The basic principle is that when the connected ends change their temperature, a voltage difference is generated on the other end. By monitoring the voltage difference at the open end, you get an accurate value for the temperature. Here are the benefits of using thermocouples over other measurement instruments:
Wider Temperature Sensing Range
Out of all the temperature measurement designs available, the thermocouple has the widest range of temperature measurement for a single device. Some thermocouples can measure from -200 degrees Celsius up to around 350 degrees Celsius. For other instruments, you may have to purchase multiple instruments in order to cover the same temperature range. Having a wide range like this one may mean a slightly lower level of precision. However, modern thermocouple designs such as those at Pyrosales Thermocouples have tolerances that are within the requirements of most industrial applications.
Higher Heat Measuring Limits
For measurement of temperatures in high heat setups such as furnaces and ovens, nothing can beat the capabilities of thermocouples. For one, thermocouples are the only common instruments that can measure temperatures that can reach up to 2,500 degrees Celsius. Other modern designs have been manufactured that can withstand temperatures of up to around 400 degrees. Beyond that, however, thermocouples are the only devices that can reliably function at much harsher environments.
While other designs can produce better precision of measurement, thermocouples are still faster and more sensitive in terms of measurement. For applications wherein you need to monitor quick changes in temperature, the thermocouple design is still the best design that can deliver real-time results. On some occasions, thermocouples have been known to respond almost three times faster than other designs.
Due to its simplicity of design and installation, thermocouples are the least expensive options even for sophisticated machines. Manufacturing of thermocouples is relatively simple compared to other designs. Thermistor and RTD designs will have a lot of catching up to do in terms of manufacturing and design in order to become more cost-effective when very high precision is not required.
Due to its operating principle, thermocouples don’t need an external power source to deliver measurements. The voltage difference is measured and is converted to temperature values. Whereas for thermistor instruments, which are based on resistance measurements, the machine would still have to deliver electrical current to be able to measure the resistance change. This measurement, in turn, would have to be converted into temperature values.
Another result of its very simple concept and construction, thermocouples are virtually indestructible compared to other measuring devices. For aggressive environments such as steel foundries and factories, the excessive vibration and abuse will quickly deteriorate other instruments, while thermocouples can withstand years of vibration and abuse with minimal damage and change in accuracy.
If your company is currently on the lookout for the best temperature measuring devices, purchasing thermocouples will save you more money in the long run because thermocouples cost less to manufacture. Depending on how many probes you’ll be needing for your operation, the cost of thermocouples is a major factor to consider. Even if thermistors may be able to give you more accurate readings, thermocouples will be able to address most of your basic temperature reading needs.