Over the past 50 years, industrial temperature controller technology has undergone tremendous changes and made a series of advancements. This article aims to introduce how industrial temperature controller technology helps users create new solutions with superior performance to meet the ever-changing application needs of customers.
In the 1960s, DIN (192 x 192 mm) moving-coil temperature controllers were standard equipment in industrial applications. However, advancements in electronics quickly changed the design and manufacturing of temperature controllers, leading to the first appearance of open printed circuit board (PCB) controllers with switching functions or proportional control via a dial. Proportional control offered lower power output near the setpoint, minimizing temperature overshoot and was the most precise control method at the time. However, proportional control still had its drawbacks: the system temperature might be slightly higher or lower than the setpoint, a phenomenon known as offset error.
In the 1970s, thanks to analog controller technology, the size of temperature controllers decreased from 1/4 DIN (96 x 96 mm) to 1/16 DIN (48 x 48 mm) without significantly affecting functionality. However, from the late 1970s to the present, analog controller technology has made almost no progress. In the 1980s, the advent of digital controllers propelled temperature control technology forward significantly: push-button and digital display technology replaced dials, better solving the problem of controller settings; simultaneously, the development of microprocessor technology made PID (Proportional-Integral-Derivative) control a reality, further improving control accuracy. Compared to proportional control, integral control eliminates offset errors, while derivative control reduces temperature overshoot and disturbances.
PID control technology offers numerous advantages for temperature control applications, but it still requires manual setting by professional engineers, a time-consuming process. Now, however, PID auto-tuning is widely used, allowing controllers to automatically calculate the optimal PID value, thus eliminating the aforementioned problem.
West Control Solutions' CAL 3300 temperature controller features complete PID auto-tuning, eliminating the need for manual parameter setting (which requires a skilled technician) and saving several minutes. Additionally, its unique dAC function prevents temperature overshoot during the preheating phase by adjusting the proportional band value, thus improving PID controller performance.
Another advantage brought about by the development of modern electronic technology is the reduction of manual operation in the application process, thus lowering the probability of errors. Temperature controllers with temperature profile functionality can configure temperature ramp rate, insulation, stepping, and loop to accurately achieve the required temperature profile and enable automatic temperature changes. This saves equipment setup time, and operators can store configuration data and freely recall it in different process flows.
In applications such as extruders, the temperature does not drop rapidly after power is cut off, thus requiring a cooling system for better temperature control. Temperature controllers have integrated heating-cooling control functions, enabling simultaneous control of both the heater and cooling system for improved application control.
In recent years, to simplify wiring and shorten installation time, it has become increasingly common to integrate other functions into temperature controllers. Some mid-range and high-end controllers support logic programming in their core process control components, integrating common control elements. The entire system is equipped with only one human-machine interface, improving end-user efficiency and simplifying process control.
For example, a German component manufacturer needs to design a temperature control solution for a furnace for heating graphite electrodes. This requires a standard controller, and any upgrades to the application require the controller to have advanced functions such as sequence management, as well as high ease of use.
The challenge lies in the fact that graphite electrodes need to be heated uniformly, but the burner heats different areas of the furnace at different rates and intensities. This can easily lead to damage to the electrodes due to overheating or uneven heating, resulting in production waste and serious economic losses.
The final solution employed an enhanced oxygen control unit to achieve pure gas heating. Our KS98-1 temperature controller is a compact micro PLC (Programmable Logic Controller) and DIN controller, perfectly conforming to existing 1/4 DIN enclosure requirements and equipped with all necessary I/O options. Compared to other DIN controllers, the KS98-1 controller, with its PLC and mathematical functions, offers more comprehensive functionality.
Standard DIN controllers typically have one or two control loops but lack sequential control or PLC logic functions. While PLC controllers can solve this problem, high-end PLC programmers are expensive to maintain and require specialized knowledge. The KS98-1 controller not only has these two functions but also retains the DIN enclosure, yet it remains a DIN controller rather than a PLC controller, making setup highly cost-effective.
Like many devices, advancements in communication technology have facilitated the integration of controllers and systems. Typically, temperature and process controllers are applied to systems as discrete devices. With communication options, users can now directly monitor and manage controls via PC or PLC systems. Furthermore, various general-purpose SCADA (Monitoring, Control, and Data Acquisition) packages or specialized control software support data logging, plotting, configuration, and management functions. Finally, the increasing demand from companies over the past few decades for high-quality control has, in turn, driven the development and advancement of PC-based data logging technologies.
For example, our customer Solent Scientific manufactures 37° culture chambers with built-in advanced microscopes for long-term human live cell research. These chambers are also equipped with timed image capture capabilities.
The CAL controller's process monitoring software supports real-time data logging, enabling Solent Scientific to ensure that the incubation chamber temperature remains within + or -0.1°C over extended periods, meeting application tolerance requirements. Furthermore, SCADA packaging significantly reduces costs and simplifies development. While temperature controllers have made substantial progress in functionality and accuracy, the setup process has remained largely automated. Now, controllers are more compact, allowing for easier integration into equipment.
How will temperature control technology develop in the future?
The need to expand controller functionality to collect process information, simplify operation, and integrate working control components has driven the development of solutions with single displays (such as HMIs and control panels) and information routing to PCs. This means that in the future, controllers will further evolve into standalone products rather than individual devices, bringing users more application advantages and control functions, and enabling more efficient and accurate monitoring of system data.
Another major trend in future controller development is customization, which involves creating custom controllers tailored to specific application needs. The latest display and programming technologies also simplify controller operation, allowing staff to easily access data, ensuring further optimization of process changes, and improving production efficiency.
Network connectivity is also a future direction for controller development: Ethernet communication technology simplifies integration under standard cabling and non-engineering connectivity conditions, further enhancing ease of use and control functionality, and optimizing temperature control. One thing is undeniable: industrial temperature controller technology will continue to evolve to meet the ever-changing application needs of customers, creating more advanced solutions and improving production efficiency and control quality.
About WEST
As a global expert in process and temperature control, WEST Control Solution products comprise four main brands: WEST, PMA, Partlow, and Cal. For over 90 years, WEST has provided high-performance, high-quality products to industries such as plastics, heat treatment, packaging, food and beverage, and life sciences.
WEST is committed to developing close partnerships with its customers. The company regularly engages in discussions and research with clients, fully considering their requirements in new product development to ensure their needs are met. WEST provides reliable, easy-to-use products with dedicated support staff offering unparalleled service. While offering standard products, we are also committed to continuous innovation, providing customized products to our customers, earning the support and trust of customers worldwide.
