automation systems and temperature sensors for industrial ovens
applications

Automation systems and temperature sensors for furnance – types, applications

Temperature is the most important measurable quantity for industrial ovens, as it has a direct impact on the quality of the final product. Because of this, it must be accurately measured and monitored using temperature sensors and automation systems. The following article is an overview of the best solutions for this application. Check it out!

Furnace temperature sensor – types

When it comes to temperature sensors used in industrial furnaces, there are no one-size-fits-all solutions. The right sensor must be selected depending on the application and the anticipated budget. The three most common types of temperature probes used in heating equipment are:

  • thermocouples

  • resistance temperature detectors (burns RTDs)

  • thermistors

Temperature measurement in industrial ovens with furnace temperature sensor

Thermocouple for industrial furnace – principle of operation

Thermocouples are measuring devices that determine temperature based on differences in the voltage created by two conductors, made of different metals, connected at the end.

These thermoelectric sensors are often used to measure the temperature inside furnaces and boilers, due to their accuracy and versatility and wide temperature range.

Type K thermocouple for furnace

K-type thermocouples, consisting of nickel combined with alumel or chromium, are very popular temperature sensors for furnaces. This is influenced by their relatively low price and their ability to be used over a wide temperature range, even from -200 to 1250°C.

High oven temperatures are also well tolerated by L, J, S, B and N type thermocouples.

Thermocouple thermowells

When using thermocouples, suitable thermowells must not be forgotten. Temperature shocks and destructive properties of the medium under test, such as corrosive vapours, have a bad effect on the delicate wires. In order to prevent this, we recommend the use of thermowells made of, among other things, ceramic or corrosion-resistant steel.

Range of thermocouples for JUMO industrial furnaces f.e gas furnace and air conditioning

Resistance temperature sensor for industrial furnaces

RTD temperature sensors operate on the principle that the resistance (resistivity) of the metal from which the conductors are made changes under the influence of the temperature being measured.

The temperature dependence of the resistance of some metals is repeatable and relatively linear, making RTD sensors highly desirable for applications requiring a high level of accuracy. Like thermocouples, these sensors can detect a wide temperature range. These features make them a very good choice for industrial furnaces.

Cost reduction with the right furnace heat sensor

Choosing the right temperature sensors for a particular furnace application can lead to significant savings and increased process efficiency, including reduced system uptime. Simply put, when the furnace system has better data, it will be able to make better decisions. In addition, the right temperature sensor can help:

  • detect potential hot spots, faults, leaks and temperature imbalances

  • increase the quality of the end product

  • reduce fuel costs

  • reduce electricity costs

Properly measured and monitored oven temperature improves the quality of the final product

PID controllers for process control in the heating unit

The highest quality of industrial furnace operation can only be achieved if not only the measuring sensors, but also the regulation of the measured parameters, are highly accurate.

Control of temperature curves

Precise temperature curves are indispensable in complex processes, which include, for example, the firing and annealing of various materials. This objective, in both through- and batch-fired furnaces and irrespective of the type of heating, is effectively met by PID controllers.

They enable:

  • accurate depiction of firing curves and display of process screens

  • recording and analysing of measurement data for each batch

  • communication via fieldbus interfaces using the JUMO visualisation software.

PID controllers, such as the JUMO ditraTRON and dTRON , are recommended for less complex processes. These units have modules prepared by us that you can use for your heating process.

Certification

Manufacturers of industrial furnaces for the aerospace and automotive industries will find JUMO equipment compliant with the requirements of the AMS2750/ CQI-9 directives. On request, components can be supplied with a certificate of conformity.

JUMO controller range for energy-efficient control in industrial furnaces

Logging, visualisation and control with JUMO variTRON PLCs

PID controllers may not be sufficient for more complex processes, e.g. when the furnace has two zones or multiple measuring points. In such cases, we recommend the JUMO variTRON 500 PLC controller, which allows you to create any programme individually tailored to your process in the Codesys programming environment.

In combination with monitoring control and process management software, these controllers offer almost unlimited possibilities for automation.

JUMO offers for industrial furnace manufacturers

JUMO offers the complete equipment needed to build and operate a furnace, from sensors and safety temperature limiters, to control devices and automation systems. In addition, we offer test and SAT and TUS test equipment to meet the requirements of AMS2750 and CQI-9. Contact us and equip your furnace with reliable and versatile components!