Science of Temperature Accuracy

The video discusses the science of achieving accurate temperature readings, particularly in industrial and scientific settings where precision is crucial. A small error in temperature measurement can lead to disaster in fields like manufacturing, aerospace, or food production.

Key points for achieving temperature accuracy:

Understanding Accuracy and Tolerance Accuracy is how close a number on a screen is to the actual physical temperature of the thing being measured.

Why Engineers Choose RTDs for Precision Temperature Measurement

Resistance temperature detectors, commonly called RTDs, are among the most trusted sensors for accurate and repeatable temperature measurement in industrial, commercial, and scientific applications. Engineers and technicians rely on RTDs because they deliver stable readings over long periods, perform well across their operating range, and respond predictably to real-world process conditions.

An RTD works by taking advantage of a simple physical principle: the electrical resistance of certain metals changes in a repeatable way as temperature changes. Most RTDs use platinum as the sensing element because it offers excellent chemical stability and a nearly linear resistance-to-temperature relationship. As temperature rises, the platinum's electrical resistance increases; as temperature falls, resistance decreases. Measurement electronics monitor this resistance change and convert it into an accurate temperature reading.

The basic design of an RTD centers on the sensing element, which is either a fine platinum wire wound around a ceramic or glass core, or a thin platinum film deposited on a flat substrate. Wire-wound RTDs tend to offer the highest accuracy and long-term stability, while thin-film RTDs provide faster response times and greater mechanical robustness. The element connects to lead wires, which carry the resistance signal back to the transmitter or control system. To protect the element from moisture, vibration, and corrosive environments, manufacturers typically encase RTDs in metal sheaths made from stainless steel or other specialized alloys.

RTDs are commonly configured in two-wire, three-wire, or four-wire designs, depending on how much measurement accuracy the application demands. In simpler setups, lead wire resistance can influence the reading, especially over long cable runs. More advanced configurations compensate for that resistance, ensuring the temperature reading reflects the sensor element itself rather than the wiring. This flexibility makes RTDs suitable for everything from short laboratory connections to long-distance industrial installations.

Standard platinum RTDs are available in multiple accuracy classes, with Class B offering ±(0.3°C + 0.005|t|), Class A offering ±(0.15°C + 0.002|t|), and higher precision versions such as 1/10 DIN providing even tighter tolerances. This level of accuracy, combined with excellent long-term stability, makes RTDs particularly valuable in applications where precision matters more than extreme temperature range. While typical RTDs operate from -200°C to 850°C depending on construction, they often outperform thermocouples in low- to mid-temperature applications, especially when tight control and minimal drift are critical.

Process industries such as chemical processing, food and beverage production, pharmaceuticals, power generation, and water treatment all use RTDs to maintain consistent product quality and system performance. Engineers widely specify RTDs because their behavior is easy to explain, easy to model, and easy to trust. When accuracy, stability, and predictable performance define the application, RTDs remain a practical and proven choice for temperature measurement.

Happy Holidays from Duro-Sense

 

ICS Acquisition Positions Duro-Sense for Accelerated Innovation and Growth

Industrial Control Solutions (ICS) has acquired Duro-Sense Corporation, combining Duro-Sense's four decades of precision temperature-sensor expertise with ICS's broad portfolio of sensing and control technologies. This creates a stronger organization capable of delivering more integrated solutions.

Duro-Sense customers will continue to receive the same high-quality thermocouples and RTDs they've trusted for over forty years, while gaining access to significantly expanded resources. Duro-Sense now joins ICS's family of instrumentation brands—including Thomas Products, Whitman Controls, and Load Controls—giving customers convenient access to temperature, pressure, level, flow, and power-monitoring products from a single supplier. This simplifies procurement, reduces administrative burden, and supports more efficient project planning.

Financial backing from LDR Partners LP provides growth capital for continued innovation in temperature measurement technology, offering long-term stability to customers in demanding industries such as aerospace, industrial processing, and energy. Manufacturing partners and suppliers benefit from ICS's established supply chain relationships and purchasing power, with potential opportunities extending beyond traditional temperature sensor applications.

The Carson, California, facility continues to operate with the same experienced engineering and manufacturing teams, maintaining existing customer relationships and service processes. Over time, customers will have access to ICS's broader technical resources, striking a balance between continuity and enhanced capability.

This integration particularly benefits industries where Duro-Sense excels, such as aerospace companies requiring extreme-precision measurements, complex industrial processes, and power-generation facilities. CEO Matt Powers emphasized the strategic value of pairing Duro-Sense's specialized expertise with ICS's broader product lines, enabling multidisciplinary teams to optimize entire control systems.

With ICS's financial and technical backing, Duro-Sense can accelerate the development of new products and advance next-generation sensing solutions. As industrial systems become increasingly integrated and data-driven, having a supplier offering multiple sensing technologies with unified engineering support and long-term stability becomes increasingly valuable. The acquisition represents a strategic investment that affirms the importance of precision temperature measurement, while also adding new capabilities and opportunities for innovation.

Industrial Control Solutions Acquires Duro-Sense Corporation, Expanding Leadership in Precision Temperature Measurement

Industrial Control Solutions (ICS), a leading provider of engineered sensing and control products, is proud to announce the acquisition of Duro-Sense Corporation, a premier manufacturer of high-quality temperature sensors based in Carson, California.

Matt Powers, CEO of Industrial Control Solutions, commented:

“We are incredibly excited to welcome Duro-Sense to the ICS family. Supported by our partners at LDR Partners LP, this strategic acquisition adds world-class thermocouple and RTD manufacturing capabilities to our growing portfolio of industrial sensing technologies.”

For more than four decades, Duro-Sense has been recognized for precision-engineered temperature measurement solutions serving the industrial, aerospace, power generation, and process industries. The company’s expertise in designing and manufacturing custom thermocouples, RTDs, and temperature sensor assemblies strengthens ICS’s commitment to providing mission-critical instrumentation for demanding applications.

With this acquisition, Industrial Control Solutions now offers an expanded range of temperature, pressure, level, flow, and power sensing products—positioning ICS as a true one-stop partner for integrated control and monitoring systems. The Duro-Sense brand joins a respected group that includes Thomas Products LLC, Whitman Controls, and Load Controls.

“By integrating Duro-Sense’s temperature expertise with our trusted product lines,” Powers added, “we’re enhancing our ability to deliver comprehensive and reliable control solutions that help our customers achieve higher performance, safety, and efficiency.”

Industrial Control Solutions looks forward to accelerating innovation and growth through this partnership, continuing to serve customers with the highest standards of quality, responsiveness, and engineering excellence.

About Industrial Control Solutions

Based in Bristol, Connecticut, Industrial Control Solutions (ICS) delivers innovative sensing and control products for industrial automation, aerospace, and power generation markets. Backed by LDR Partners LP, ICS unites a family of leading instrumentation brands including Thomas Products, Whitman Controls, Load Controls, and now Duro-Sense.

About Duro-Sense Corporation

Founded in Carson, California, Duro-Sense Corporation specializes in the design and manufacture of precision temperature sensors, including thermocouples and RTDs, for critical industrial and OEM applications. With a reputation for quality and engineering expertise, Duro-Sense serves customers across North America and internationally.

Key Principles to Accuracy in Temperature Measurement

Accurate temperature measurement is critical across industries, and thermocouples remain the most widely used sensors for this purpose. Their accuracy depends not just on their inherent design, but on how they are selected, manufactured, installed, and maintained. Thermocouples come in two tolerance classes—Standard Limits of Error and Special Limits of Error—with the latter offering tighter accuracy for applications where precision is essential. ASTM E230 is the governing standard in the United States, and examples show how even small differences in tolerance can translate into several degrees of accuracy at high operating temperatures.

Different thermocouple types (K, J, T, E, N, S, R, B, and C) serve different needs. Base metal types like K, J, T, and E are common for general applications, while noble and exotic metal types such as S, R, B, and C are used for very high-temperature or specialized environments. Each has its own strengths, weaknesses, and atmospheric requirements, making proper selection a critical first step toward reliable measurement.

Beyond selection, accuracy is shaped by immersion depth, response time, cold junction compensation, and protection against interference or “noise.” Errors can also arise from poor manufacturing, material degradation, oxidation, or contamination. Best practices include using quality materials, ensuring correct installation, shielding against electrical interference, and performing regular calibration. Importantly, calibration does not “fix” a sensor but reveals its error, allowing process instruments to adjust accordingly.

In short, precision temperature measurement is achievable with the right thermocouple, properly specified tolerances, careful installation, and ongoing calibration. By following these principles, companies can ensure repeatability, stability, and credibility in their processes—turning what may seem like a simple sensor into a critical component of process accuracy and reliability.

Duro-Sense Corporation
Address: 869 Sandhill Avenue Carson, California 90746
Phone: (310) 533-6877
Fax: (310) 533-0330
E-mail: sales@duro-sense.com

Understanding the Seebeck Effect and Its Role in Thermocouple Technology

The Seebeck Effect describes the direct conversion of heat into electricity through the interaction of two different conductive materials. In 1821, German physicist Thomas Johann Seebeck discovered that when he joined two dissimilar metals at two junctions and exposed the junctions to various temperatures, an electric current flowed through the circuit. This discovery formed the foundation of thermoelectric science and remains at the heart of modern thermocouple technology.

When two metals touch, the energy levels of their electrons differ; heating one junction excites the electrons in that region, causing them to migrate toward the cooler side. This electron movement produces a measurable voltage, often referred to as the thermoelectric voltage or electromotive force (EMF). The size of this voltage depends on the type of metals used and the temperature difference between the hot and cold junctions.

Thermocouples utilize this principle in practical, industrial, and scientific measurements. A thermocouple consists of two wires made of different alloys joined together at one end, which forms the measuring junction. This junction contacts the surface, fluid, or gas where the temperature needs to be determined. The other ends of the wires connect to a reference junction maintained at a known temperature or electronically compensated. Because the thermoelectric voltage directly relates to the temperature difference, instruments can convert this voltage into an accurate temperature reading.

Engineers, researchers, and technicians use thermocouples across a wide range of applications. Power plants rely on them to monitor steam lines and turbine temperatures. Manufacturers use them to control furnaces, ovens, and heat treatment processes. The oil and gas industry relies on the durability of its equipment in extreme conditions. Medical devices, aerospace equipment, and food processing systems also rely on thermocouples for reliable, real-time monitoring.

The simplicity of thermocouple design makes them durable and versatile. They contain no moving parts, require no external power, and tolerate high vibration, pressure, and temperature. Different combinations of alloys, such as chromel-alumel (Type K) or copper-constantan (Type T), provide engineers with thermocouples optimized for various ranges and environments. The choice of alloy pair determines sensitivity, stability, and accuracy.

The Seebeck Effect, while nearly two centuries old as a scientific discovery, continues to drive innovation. Modern thermocouples pair the principle with digital electronics for faster response times, automated compensation, and integration with data acquisition systems. This ensures industries can maintain safety, efficiency, and product quality in demanding processes.

Understanding the Seebeck Effect provides clarity on why thermocouples remain the most widely used temperature measurement device in the world. The direct link between heat and voltage delivers both simplicity and reliability. From research laboratories to industrial plants, this principle continues to support critical operations where accurate and reliable temperature measurement is crucial.