Showing posts with label temperature sensor. Show all posts
Showing posts with label temperature sensor. Show all posts

Tuesday, April 30, 2024

The Future of Temperature Sensors in Manufacturing: Innovations in RTDs and Thermocouples

The Future of Temperature Sensors in Manufacturing

Over the next five years, manufacturing will witness significant advancements in temperature sensing technologies, particularly in resistance temperature detectors (RTDs) and thermocouples. These advancements will be driven by material science, wireless networking, and artificial intelligence breakthroughs, revolutionizing how temperature is monitored and controlled in manufacturing processes.

Material Science Innovations:

Material science will play a crucial role in enhancing the performance and durability of RTDs and thermocouples. Researchers are developing novel materials with higher temperature stability, improved accuracy, and faster response times. For instance, using graphene-based materials in RTDs has shown promising results, offering exceptional thermal sensitivity and conductivity. Similarly, advancements in ceramic materials for thermocouples will enable them to withstand even harsher industrial environments while maintaining accuracy.

Wireless Networking Integration:

Integrating wireless networking technologies like the Industrial Internet of Things (IIoT) and 5G will transform how temperature sensors are deployed and managed in manufacturing settings. Wireless RTDs and thermocouples will become increasingly prevalent, eliminating the need for extensive wiring and enabling real-time data transmission. This will significantly simplify installation, reduce maintenance costs, and improve the flexibility of temperature monitoring systems. Furthermore, the low latency and high bandwidth of 5G networks will enable faster data processing and more responsive control systems.

Artificial Intelligence-Driven Analytics:

Artificial intelligence (AI) will revolutionize how temperature data is analyzed and utilized in manufacturing processes. Machine learning algorithms will process temperature data collected by RTDs and thermocouples, identifying patterns, anomalies, and potential issues in real-time. Predictive AI-powered maintenance models will anticipate temperature-related equipment failures, allowing for proactive maintenance and minimizing downtime. Additionally, AI-driven optimization algorithms continuously adjust process parameters based on temperature data, ensuring optimal performance and energy efficiency.

Self-Calibrating and Self-Healing Sensors:

The next generation of RTDs and thermocouples will incorporate self-calibrating and self-healing capabilities. Advances in sensor design and materials will enable these devices to automatically calibrate themselves, eliminating the need for frequent manual calibration. Furthermore, self-healing mechanisms will allow the sensors to detect and recover from minor damage or degradation, extending their lifespan and reducing maintenance requirements.

Miniaturization and Integration:

Miniaturization of temperature sensors will continue progressing, enabling the development of compact and highly integrated sensing solutions. Micro-electromechanical systems (MEMS) technology will be leveraged to create miniaturized RTDs and thermocouples seamlessly integrated into various manufacturing equipment and processes. This miniaturization will allow for more precise temperature measurements in confined spaces and enable the deployment of dense sensor networks for comprehensive temperature monitoring.


The future of temperature sensors in manufacturing industries looks promising, with RTDs and thermocouples set to undergo significant advancements over the next five years. Material science innovations will enhance performance and durability, while wireless networking integration will streamline deployment and data transmission. AI-driven analytics will unlock new insights and optimization opportunities, and self-calibrating and self-healing capabilities will reduce maintenance requirements. Miniaturization and integration will enable more precise and comprehensive temperature monitoring. These advancements will ultimately improve manufacturing industries' process control, efficiency, and product quality.


Saturday, March 23, 2024

Duro-Sense, Inc. - Precision in Temperature Sensing Technology

Precision in Temperature Sensing Technology

Duro-Sense, Inc. stands as a beacon of excellence and reliability in the intricate world of temperature measurement and control. Established as one of the top providers in the USA, this prestigious company has carved out a significant niche in the market for thermocouples and RTD (Resistance Temperature Detector) temperature assemblies. Their success lies in meticulous materials selection, unmatched craftsmanship, rigorous quality procedures, and widespread acceptance by leading companies across demanding sectors such as aerospace, medical equipment, and industrial process control.

At the heart of Duro-Sense's philosophy lies a commitment to quality that starts with selecting materials. Understanding that the foundation of any superior temperature sensing solution is in the raw materials used, Duro-Sense employs an extensive selection process. This process involves sourcing from only the highest-grade suppliers and conducting extensive testing to ensure that all materials meet their stringent standards. This meticulous approach ensures that every component, from the smallest wire to the housing of the thermocouple itself, contributes to the overall integrity and reliability of the finished product.

Craftsmanship at Duro-Sense is another pillar of its success. Here, the fusion of traditional skills and modern innovation takes center stage. Skilled artisans with years of experience work in tandem with cutting-edge manufacturing techniques to create products that are not only precise but also durable. Every thermocouple and RTD temperature assembly that leaves the Duro-Sense facility is a testament to the company's dedication to precision engineering and quality. This unique blend of craftsmanship and contemporary technology sets Duro-Sense apart in a crowded market.

Moreover, its rigorous quality procedures show the company's commitment to excellence. Duro-Sense does not merely aim to meet industry standards; it strives to exceed them. Every product undergoes exhaustive tests to ensure flawless performance under even extreme conditions. This relentless pursuit of quality means that Duro-Sense products are not just reliable but consistently outstanding. This commitment has earned the company certifications and the trust and loyalty of customers across various industries.

The acceptance of Duro-Sense's thermocouples and RTD assemblies by leading companies in aerospace, medical equipment, and industrial process control speaks volumes about its quality and reliability. These industries, known for their uncompromising standards and rigorous demands, trust Duro-Sense for their temperature sensing needs. Duro-Sense earns its trust by consistently delivering high-quality, reliable, and accurate temperature-sensing solutions that perform under the most challenging conditions.

Duro-Sense, Inc. has established itself as a temperature measurement and control leader. The company consistently delivers products that set the standard for reliability and precision through its meticulous materials selection, unparalleled craftsmanship, and rigorous quality procedures. The widespread acceptance of Duro-Sense's products by industry leaders across aerospace, medical equipment, and industrial process control is a testament to their unmatched quality and performance. In the demanding world of temperature sensing, Duro-Sense, Inc. is not just a provider but a trusted partner in precision and reliability.


Wednesday, February 7, 2024

A Benchmark of Excellence: Duro-Sense An Accredited ISO/IEC 17025:2017 Testing and Calibration Laboratory

Duro-Sense An Accredited ISO/IEC 17025:2017 Testing and Calibration Laboratory

An accredited ISO/IEC Testing and Calibration Laboratory represents a hallmark of excellence and reliability in manufacturing, especially for temperature sensor manufacturers. This accreditation, based on the ISO/IEC 17025 standard, signifies that a laboratory has met rigorous international standards for testing and calibration. It ensures the laboratory's competence, impartiality, and consistent operation, offering manufacturers and their clients a solid foundation of trust and quality assurance.

For temperature sensor manufacturers, achieving accreditation under ISO/IEC 17025 is not just a matter of prestige but a critical business necessity. Temperature sensors are crucial in various industries, including aerospace, healthcare, manufacturing, food safety, and environmental monitoring. In these sectors, the accuracy, reliability, and precision of temperature readings can significantly affect safety, security, regulatory compliance, and product quality. Therefore, manufacturers must ensure their sensors operate within the specified parameters under all conditions.

Becoming an accredited ISO/IEC Testing and Calibration Laboratory involves a thorough evaluation by an authoritative body. This evaluation assesses the laboratory's ability to produce precise, accurate, and repeatable testing and calibration results. The assessment covers every aspect of the laboratory's operations, from its staff's qualifications and ongoing training to the maintenance and calibration of its equipment and the validity and appropriateness of its testing methods.

Achieving this accreditation signifies that a temperature sensor manufacturer maintains the highest quality control and assurance standards. It ensures that the sensors they produce undergo rigorous testing and calibration, validated against international benchmarks. This level of validation is invaluable, as it gives customers confidence in the sensors' accuracy and reliability, which is paramount for critical applications.

Moreover, the importance of this credentialing extends beyond customer assurance to compliance with global regulations and standards. Many industries require accredited laboratories for testing and calibration to meet regulatory and compliance needs. For temperature sensor manufacturers, having an in-house accredited laboratory or partnering with an accredited facility means they can navigate these regulatory landscapes more smoothly. It facilitates more accessible access to international markets, as the accreditation is widely recognized and respected across borders.

Furthermore, maintaining ISO/IEC 17025 accreditation fosters a culture of continuous improvement within the laboratory. It requires regular audits and assessments, which encourage laboratories to constantly refine their processes, upgrade equipment, and enhance the skills of their personnel. This drive for excellence improves the quality of the testing and calibration services and pushes the entire manufacturing process toward higher standards.

For temperature sensor manufacturers, credentialing an ISO/IEC Testing and Calibration Laboratory is a critical asset. It represents a commitment to quality, accuracy, and reliability that resonates throughout the industry and with the end-users. This accreditation provides a competitive edge, opening doors to global markets and ensuring compliance with industry regulations. It embodies a manufacturer's dedication to excellence and their responsibility towards ensuring the safety and satisfaction of their customers.

Duro-Sense has achieved accreditation under ISO/IEC 17025:2017 and fulfills R205-Calibration, distinguishing itself as a premier testing and calibration facility committed to global standards. By satisfying the rigorous criteria outlined in ISO/IEC 17025:2017, Duro-Sense has proven its expertise, fairness, and dependable performance. The international standard for calibration and testing laboratories acknowledges Duro-Sense's dedication to excellence.


Tuesday, May 16, 2023

Looking for High Accuracy in Temperature Measurement?

Looking for High Accuracy in Temperature Measurement?

Industrial temperature measurement is a critical aspect of many processes, including manufacturing, processing, and energy production. The choice of temperature sensor is vital to ensure accuracy, reliability, and durability. Several types of temperature sensors are available, including Resistance Temperature Detectors (RTDs), Thermocouples, Thermistors, and Infrared Sensors. Each sensor type has its unique strengths and weaknesses. However, after a thorough analysis, RTDs generally offer the highest level of accuracy in industrial settings.

RTDs (Resistance Temperature Detectors) are temperature sensors that use the predictable increase or decrease in electrical resistance of some materials with rising or falling temperatures. The most common RTD type is platinum (Pt100 or Pt1000) due to its stability, repeatability, and nearly linear temperature-resistance relationship. RTDs have a typical accuracy within ±0.1°C, making them among the most accurate temperature sensors available.

Thermocouples are a type of temperature sensor made from two dissimilar metals joined together at one end, and changes in temperature cause a small voltage, which can be measured and interpreted. While they are robust and can handle extreme temperatures, their accuracy is lower than that of RTDs, generally within ±0.5°C to ±2°C.

Thermistors are temperature-sensitive resistors, typically made from ceramic or polymer. While they can offer high accuracy, they have a non-linear response and a limited temperature range, making them less suitable for broad industrial applications.

Infrared sensors measure temperature by capturing the infrared energy emitted by an object. They are non-contact sensors, which can be advantageous in certain situations, but they also require a clear line of sight and can be affected by dust, fog, or other environmental factors.

RTDs are the primary choice for high-accuracy industrial temperature sensing for several reasons:

  1. Their accuracy is superior to most other types, typically within ±0.1°C.
  2. They exhibit good long-term stability, making them reliable over the lifespan of many industrial processes.
  3. Platinum RTDs are highly repeatable and have a nearly linear temperature-resistance relationship, making them easy to interpret and integrate into control systems.

However, it's important to note that the choice of the sensor should ultimately depend on the specifics of the application, including the temperature range, required accuracy, environmental conditions, and budget. Thermocouples, for instance, might be more suitable for high-temperature applications, and infrared sensors may be necessary when a non-contact measurement is required.

In conclusion, RTDs are recommended for a broad range of industrial applications requiring high accuracy, stability, and repeatability. Nevertheless, a careful evaluation of the specific requirements of each application should always be carried out before making a final decision.

Direct: 310-533-6877

Fax: 310-533-0330

869 Sandhill Avenue

Carson, California 90746

Wednesday, April 6, 2022

Duro-Sense 100 OHM Platinum RTD Temperature Sensors

Duro-Sense RTD Sensors

RTDs (Resistance Temperature Detectors) are temperature detecting devices that vary their resistance value when surrounding temperature changes. RTD sensing elements use well-known materials that change resistance in a predictable and repeatable manner. Their popularity and general use are outcomes of the RTD's predictability and stability. 

The most common type and material of RTD is the 100-ohm platinum sensor. Its use is ubiquitous in the laboratory and industrial process applications going back many decades. The precision, reproducibility, and stability of 100-ohm platinum RTDs (PT100) are well known. 

For the most part, resistance temperature detectors (RTDs) fall into two main categories. Thin-film elements are one form of RTD, and wire-wound elements are the other. Each type provides advantages in certain situations and purposes. The more common design, wire-wound, is a length of tightly coiled wire wrapped around a ceramic or glass bobbin. Because the wire and wrapping are delicate, it is usually enclosed in an encased metallic tube to protect them from stress and vibration. 

The 100-ohm platinum RTD provides accurate temperature readings with excellent stability and repeatability. They are also very resistant to electrical noise, making them ideal for temperature monitoring in industrial facilities near motors, generators, and high voltage equipment. 

The American and European (known as the DIN or IEC standard) 100-ohm platinum RTD standards are the same, with the IEC standard considered the default for PT100. According to the IEC751 standard, the RTD must have:

  •  The electrical resistance of 100.00 O at 0°C 
  • A TCR (temperature coefficient of resistance) of 0.00385 O/O/°C between 0 and 100°C. 

Because resistance is used to measure temperature in 100-ohm platinum RTDs, the lead wires, connections, and measurement devices contribute extra resistance, requiring external compensation to offset the error. A solution is found by inserting a third or fourth lead wire inversely proportional to the external resistances.

Duro-Sense Corporation

Thursday, February 17, 2022

Thermocouples Used in The Plastics Molding and Forming Industry

Thermocouples Used in The Plastics Molding and Forming Industry

The term "plastics thermocouple" refers to a thermocouple used in the plastics, packaging, and rubber industries. Plastic thermocouple installations include injection molding, thermoforming, vacuum forming, and extruding machines to precisely measure the temperature of the plastic molds and nozzles. While plastic thermocouples come in various configurations such as bayonet, washer style, shim style, nozzle, and right angle, their essential components remain the same. 

Plastic thermocouples are typically calibrated to ANSI types J or K. Thermocouples lead wire comes in a variety of insulation and protection options, including high-temperature fiberglass, PVC, stainless steel braided fiberglass, and stainless steel flexible armor cable. Bare leads, male thermocouple jacks, female thermocouple plugs, or spade lugs are the most common electrical connections. 

Bayonet designs are straight or right-angle configurations, with industry-standard bayonet fittings easily retrofitted to most injection molding and plastics processing equipment. These fittings have adjustable depth and are spring-loaded to contact the media. The thermocouple sensing junction is welded or crimped directly to the washer or shim in washer and shim thermocouples. 

Bayonet thermocouples have a tube and wire design with stranded thermocouple cable running the length of the probe, and a metallic sensor is a stainless steel from the 301, 304, or 316 series. The thermocouple has either a grounded or an ungrounded junction. While the probe has a speedy response, a grounded T/C junction welded to the probe's tip can conduct electrical noise back to the instrumentation. An ungrounded junction is isolated from the metallic sensor and prevents the transmission of electrical noise. On the other hand, Ungrounded T/C junctions are slightly slower to respond to temperature changes.

Saturday, May 15, 2021

The "Big Eight" Thermocouple Types

Thermocouple Types

In the United States, each thermocouple class carries a notation defined by a single letter. The Instrument Society of America (ISA) pioneered this method, which was introduced as an American Standard in 1964 to avoid proprietary names. The American National Standards Institute (ANSI-MC96.1, 1982) and the American Society for Testing and Materials (ASTM 230-87) use the National Institute of Standards and Technology Monograph 125 reference tables as the basis for standardization. As noted in the ANSI and ASTM standards, the letter designations define the tables. Thus, they may be applied to any thermocouple with a temperature-EMF relationship that agrees within the tolerances defined in the standards, irrespective of the thermocouple's composition. 

Only a few of the approximately 300 different temperature measuring thermocouples defined and tested have achieved mass acceptance because they exhibit more desirable electrical and physical characteristics. Resultantly, these eight preferred thermocouple types are the most widely used in industrial, commercial, medical, and aerospace applications. 

  1. Type B = platinum- 30% rhodium/platinum-6% rhodium - 0 to 1820°C *
  2. Type E = nickel-chromium alloy/a copper-nickel alloy -270 to 1000°C*
  3. Type J = iron/another slightly different copper-nickel alloy -210 to 1200°C*
  4. Type K = nickel - chromium alloy/nickel - aluminum alloy -270 to 1260°C
  5. Type N = nickel-chromium-silicon alloy nickel-silicon alloy -270 to 1300°C*
  6. Type R = platinum- 13% rhodium/platinum -50 to 1768°C*
  7. Type S = platinum- 10% rhodium/platinum -50 to 1768°C*
  8. Type T = copper/a copper-nickel alloy -270 to 400°C*

* temperature range as per NIST Table I: Thermocouple Types Definitions.

Certain combinations of alloys, such as Type J and K, have become popular as industry standards.  Cost, availability, melting point, chemical properties, stability, and output are all drivers for thermocouple application. Different types of thermocouples are best suited for different uses/applications. Thermocouple selection also depends on the temperature range and accuracy needed. Other selection criteria include the chemical inertness of the thermocouple material and whether it is magnetic or not. 

For more information about thermocouples, contact Duro-Sense by calling 310-533-6877 or visiting

Wednesday, April 21, 2021

Shorter Lead Times Make Happier Customers

Shorter Lead Times Make Happier Customers

Customer satisfaction and loyalty can be closely tied to how quickly customers receive their orders. In terms of supply chain, lead time is a big part of any successful business. Reducing lead times as much as possible is vital to a company’s success.

Manufacturing lead time is the total time required to manufacture an item. From an operational standpoint, One should be aware that there are many different types of lead times:

  • Material lead time is the amount of time it takes a customer to place an order with a supplier and receive it; from when the order was confirmed to when they have it on hand.
  • Pre-production lead time is the amount of time required for the supplier to create a work order. This is sometimes called planning time. It primarily takes the form of paperwork.
  • Production or Factory lead time is the actual amount of time the supplier needs to manufacture the product.
  • Post-production lead time is the time required for a customer to receive an item from dock to inventory. Depending on the product, it could entail anything from inspection to quarantine time.
  • Fixed lead time refers to a part of production or factory lead time that is not dependent on the order quantity.
  • Variable lead time, is the part of production or factory lead time that is dependent on the order quantity.
  • Cumulative lead time is the term used to describe the entire amount of time required, from order confirmation to the delivery of the product. It is the aggregate of material lead time and production or factory lead time

Accurately forecasting and reducing lead time is a vital element of any manufacturing operation. The need for a timely and accurate response to inquiries, on-time order completion, and the ability to respond quickly in an emergency must be at the core of a manufacturer’s ideals. They are keys to maintaining customer satisfaction, a competitive advantage, and a definitive reputation in the marketplace.

Duro-Sense has spent years researching, analyzing and implementing methods and procedures to continually improve our ability to work efficiently in pre-production and production, and to enable us to respond quickly and seamlessly to a customer’s requirements and unexpected emergencies.

Strategies including:

  • Supply chain re-evaluation
  • Domestic material sourcing
  • Warehouse reorganization
  • Creative inventory control
  • Re-training and cross-training personnel
  • Improved information flow and accuracy

This approach, has given us the ability to have more efficient and streamlined production and customer interaction, which leads to faster response time and shorter lead times. Duro-Sense has moved to the forefront of on-time delivery and the ability to seamlessly adapt to any urgent customer need.

Customers don’t like waiting. Production lead time can be the critical component in the success of your business. Like a bad movie, or a dull and tedious speech, shorter is always better. Choosing the right manufacturer is essential when trying to calculate lead time. After over four decades in manufacturing, Duro-Sense has developed valuable strategies regarding the most effective ways to reduce lead times without compromising quality. Let us prove it to you.

Duro-Sense Corporation

Sunday, March 21, 2021

Thermocouple Stability - Understanding Drift

Understanding Drift

Base-metal thermocouples, ANSI standard Types J, K, T, E, have innate thermoelectric instability related to time or temperature-dependent instabilities in many of their chemical, physical,  and electronic properties. 

When a thermocouple is used to measure the temperature of a particular environment, it can be expected that the measured voltage does not change if the temperature of that environment remains constant.  Actually, the voltage can change over time, even though the temperature of the environment remains constant:  this phenomenon is called DRIFT.  Drift is a source of error in thermocouple measurement. 

Drift occurs because of metallurgical changes in the conductors during the operation of the thermocouple.  Because these changes are time dependent, the voltage change from the expected value, called drift, is also time dependent.  An example of drift is shown below, in Figure 10, for a 1.5mm bare wire Type ‘K’ thermocouple exposed at 500ÂșC.  The change in voltage is reported as a function of the exposure time. 

Metallurgically, drift can be distinguished in the following:

  • Surface modifications, which are related to changes in the conductors because of interactions between the conductors and the environment around the them.
  • Bulk modifications, which are related to changes in the volume of the conductors.

Some examples of surface modifications can be identified below: 

  • Oxidation (bare wire configurations)
  • Depletion of elements from the conductors [bare wire/mineral insulated metal sheathed(MIMS)]
  • Contamination from the environment (bare wire/MIMS configuration)
  • Interaction with the insulator (MIMS configuration)
  • Interaction with the sheath (MIMS configuration)

In relation to bulk modifications, the following phenomena can occur: 

  • Phase transformations
  • Short/long range ordering transformations
  • Grain growth
  • Residual strain and dislocations annihilation
  • Recrystallization

Duro-Sense Corporation


{1} R.E. Bentley, “Long-term drift in mineral-insulated Nicrosil-sheath type K thermocouple”. Sensor and Actuators A, 24(1990) 21-26

Saturday, October 24, 2020

Temperature Sensors for Aerospace and Space Exploration

Temperature Sensors for Aerospace and Space Exploration

Duro-Sense Corporation provides the precision temperature sensors to the aerospace, aviation, and space industries and has a reputation for manufacturing the finest quality temperature sensors available. 
Robert J. Collier Trophy
Robert J. Collier Trophy

Duro-Sense engineers bring proven solutions to your most difficult problems. The company has a long history of supplying thermocouples and RTDs to the top manufacturers in the aerospace industry. The Duro-Sense R&D department is staffed with some of the industry's most qualified people, working in the most modern facilities to help advance the state of the art in temperature measurement. 

Duro-Sense products are time-tested and proven to be ultra-reliable, accurate, and of extremely high value. 

Contact Duro-Sense Corp. today with you aerospace or space exploration temperature sensing requirement. Call them at 310-533-6877 or visit their website at

Friday, September 25, 2020

Engine-Compressor Thermocouples for Offshore Platform Generators

Engine-Compressor Thermocouple

Providing power to a broad range of sophisticated equipment on offshore oil and gas platforms requires a large amount of uninterrupted electricity. Pumps, valve operators, essential communications, turntables, engines, and safety devices are just a subset of the environment of drilling and processing that needs a reliable power source. A large amount of electrical power, not unlike a small town, is required. Electric generators provide comfort heating, cooling, water desalination, food storage, and even waste processing. 

On offshore platforms, conditions are harsh. Equipment and components must be robust to function correctly and decrease the need for regular maintenance. 

Temperature is one of the compressor's most critical measurement parameters and its accuracy can directly affect compressor efficiency. Analysis reveals that errors in temperature calculation account for over 80% of efficiency errors. More aspects of compressor temperature measurement and improved methods of temperature measurement are required.  Thermocouples are used to measure inter-stage gas compressor temperature and outlet gas temperature.  

A specialized temperature sensor known as an 'engine-compressor thermocouple' measures temperature in these applications. These are heavy-duty, specially built temperature sensors that monitor a variety of parameters including exhaust gases and lubricant temperatures. Such sensors are time-tested and designed to withstand the harsh mechanical and environmental conditions of offshore marine conditions. The thermocouple's prime requirement is to be robust enough to withstand a high vibration and corrosive environment and still be accurate and fast responding.

The engine-compressor thermocouple provides oil and gas platform technicians with precise measurements, excellent accuracy, and rapid response times. These thermocouples are also easily checked for calibration, removed, and replaced if necessary.

Duro-Sense Corporation

Saturday, May 23, 2020

Resistance Temperature Detector (RTD) Catalog

Resistance Temperature Detectors (RTD’s) operate under the principle that the electrical resistance of certain metals increases or decreases in a repeatable and predictable manner with a temperature change. RTD’s may have a lower temperature range than some thermocouples and a slower response time, however, they are more stable and repeatable over long periods of time. RTD’s higher signal output makes them easier to interface with computers and data loggers and reduces the effects of radio frequency interference. RTD’s are used in the plastic processing industry, environmental test chambers, motor windings, pumps and bearings, ovens, kilns, waste treatment and the pulp and paper industry, as well as many other applications.


Thursday, January 30, 2020

Full Duro-Sense Product Catalog Now Available

Duro-Sense Corporation designs and manufactures the finest quality thermocouples, RTDs, and custom temperature assemblies used in a wide variety of industries including aerospace, medical, power generation, food and beverage, pulp & paper, chemical processing, plastics, pharmaceutical, and life science. Duro-Sense products are known throughout these industries for their quality and reliability.

From simple wire and tube assemblies for the plastics industry, to mineral insulated and multipoint thermocouples, to custom sensors for specific applications, Duro-Sense can design, manufacture, and deliver solutions to virtually any temperature related application.

Wednesday, August 21, 2019

What Kind of Thermocouple Should I Use?

Temperature measurementWhat kind of thermocouple should I use? Depends on several variables related to the system to be tracked, such as its media / process environment compatibility, the frequency and precision of the necessary measurements, and the regulatory climate in your sector.

Temperature measurement in many industries, from refining to pharmaceuticals to aerospace, is a key parameter in manufacturing and processing operations. Precise temperature monitoring helps to ensure safe, efficient and optimal results.

A thermocouple is invariably the measuring tool of choice for applications above 1400° F, but the selection of the ideal industrial thermocouple also requires knowledge of the process where the device will be used.


First, consider whether the thermocouple is itself in direct contact with the process media or whether it is incorporated into a thermocouple assembly that includes a thermowell. Thermowells are metal, glass, or ceramic tubes that protect the thermocouple against corrosive, fast-flowing or highly hot process media. About 75% of heavy industry thermocouples use thermowell assemblies; these industries include refining, petrochemical, the pulp and paper industry, and power generation.


The thermocouple junction design depends on the applications requirements for response speed and the likelihood of electrical noise being conducted through the process. A thermocouple has three variations of sensing tip (or junction): Exposed junction, where the exposed wire tips and welded bead have no covering or protection; Grounded junction, where the welded bead is in physical contact with the thermocouple's sheath; Ungrounded junction, where the tip is inside the thermocouple sheath, but is electrical (and somewhat thermally) insulated from the sheath (no sheath contact).


Material selection is the second criteria to choose. A vast majority of industrial thermocouples are made from stainless steel, but specialized alloys such as Inconel 600, Hastelloy X, Monel,  and other unique metals are required in certain applications.


Next, you have to consider the mounting arrangement. You need to determine whether a more traditional industrial thermocouple/well/head design is required, or if some sort of flexible or remote thermocouple sensor is required for use in a hard to access area.


Last, you have to decide the "type" of industrial thermocouple you need. In the case of thermocouples, "type" refers to the composition of metal wires in the instrument whose physical properties respond to changes in temperature. Different metal compositions have different temperature ranges and other properties that make them suitable for use in special applications, or inappropriate for use.

  • Type J thermocouples use iron for the positive leg and copper-nickel (constantin) alloys for the negative leg. They may be used unprotected where there is an oxygen-deficient atmosphere, but a thermowell is recommended for cleanliness and generally longer life. Because the iron (positive leg) wire oxidizes rapidly at temperatures over 1000 deg.F, manufacturers recommend using larger gauge wires to extend the life of the thermocouple when temperatures approach the maximum operating temperature.
  • Type K thermocouples use chromium-nickel alloys for the positive leg and copper alloys for the negative leg. They are reliable and relatively accurate over a wide temperature range. It is a good practice to protect Type K thermocouples with a suitable ceramic tube, especially in reducing atmospheres. In oxidizing atmospheres, such as electric arc furnaces, tube protection may not be necessary as long as other conditions are suitable; however, manufacturers still recommend protection for cleanliness and prevention of mechanical damage. Type K thermocouples generally outlast Type J, because the iron wire in a Type J thermocouple oxidizes rapidly at higher temperatures.
  • Type N thermocouples use nickel alloys for both the positive and negative legs to achieve operation at higher temperatures, especially where sulfur compounds are present. They provide better resistance to oxidation, leading to longer service life overall.
  • Type T thermocouples use copper for the positive leg and copper-nickel alloys for the negative leg. They can be used in either oxidizing or reducing atmospheres, but, again, manufacturers recommend the use of thermowells. These are good stable thermocouples for lower temperatures.
  • Types S, R, and B thermocouples use noble metals for the leg wires and are able to perform at higher temperatures than the common Types J and K. They are, however, easily contaminated, and reducing atmospheres are particularly detrimental to their accuracy. Manufacturers of such thermocouples recommend gas-tight ceramic tubes, secondary porcelain protective tubes, and a silicon carbide or metal outer protective tube depending on service locations.
For more information about industrial thermocouples, contact Duro-Sense Corporation. Call them at 310-533-6877 or visit their web site at

Friday, July 26, 2019

Duro-Sense Corporation: Celebrating Our 40th Year in Business

Duro-Sense designs and manufactures temperature sensors and assemblies used in power generation, plastics production, semiconductor processing, environmental control, packaging, aerospace, medical equipment, foodservice equipment and a myriad of other industries. Duro-Sense partners with customers to optimize their temperature sensing processes, thereby assisting in improving their customers efficiency and profitability.

Since 1979, Duro-Sense has grown exponentially in product capability and market experience. The company today continues to succeed by operating under a simple core value – providing customers with superior products, meticulously engineered for their individual requirements.

Thursday, July 11, 2019

Duro-Sense: A Long History of Solving Tough Temperature Sensing Problems

Duro-Sense Temperature SensorsWith engineering, design, and support resources available at their headquarters in Southern California, Duro-Sense delivers value-added temperature sensing solutions that improve operations and increase profitability for customers in the power generation, alternative energy, plastics, medical, gas & oil, chemical, refining, mining, agricultural, food service, pharmaceutical, and aerospace industries.

Duro-Sense offers their customers products and services designed to provide outstanding value and cost savings throughout the customer's equipment life span. By integrating the highest quality standards, state-of-the-art machinery, and decades of application experience, Duro-Sense assists customers through:
  • Improved product quality
  • Optimize asset uptime and performance 
  • Lower total cost of operation and maintenance
  • Increase equipment reliability
  • Improve plant and personnel safety


Technical Analysis — Duro-Sense can identify temperature sensor operational issues that may be constraining output or elevating operating costs, and then recommend laser-focused solutions.

Reliability and Efficiency Services — Duro-Sense lends their decades of hands-on experience to offer practical temperature sensing solutions that improve the performance, efficiency, and reliability of your process control equipment - all while lowering your total cost of ownership.

Loop Design, Integration and Engineering Support — Duro-Sense engineers engage with their customers, providing support for grassroots project planning, system design, or project management requirements.

Equipment Life Cycle Optimization — Through a combination of assessments and technology, Duro-Sense experts help customers benchmark operational performance, define key metrics, and implement precise sensor solutions to achieve long-term operational goals.

Intelligent Product Design — By employing an array of sophisticated products, services, and software that collects, examines and understands data, Duro-Sense helps customers use predictive analytics to take action and improve asset reliability and reduce downtime.

Have a challenging temperature sensing requirement? Call Duro-Sense.

Duro-Sense Corporation

Friday, May 24, 2019

Quick Comparison of Temperature Sensors

Thermocouples are commonly used because of their simplicity, reliability, and relative low cost. They are self-powered and eliminate the need for a separate sensor power supply. Thermocouples are quite durable when selected for a given application appropriately. Thermocouples can also be used for applications with high temperatures.

Resistance temperature detectors (RTDs) are attractive alternatives to thermocouples when the output is desired to be highly accurate, stable and linear (i.e. just how close the calibration curve looks a straight line). The superior linearity of relative temperature resistance enables simpler signal processing devices for RTDs than thermocouples.

Thermistors are similar to RTD because they're a resistance measurement device, but thermistors use a very cheap polymer or ceramic material as the element in lieu of the use of pure metal.

For more information on any type of industrial or OEM temperature sensor, contact Duro-Sense by calling 310-533-6877 or by visiting

Tuesday, March 12, 2019

Theory of RTD Operation

Theory of RTD OperationAn RTD is a temperature measuring device that changes resistance with temperature change, rather than changing voltage, as with a thermocouple.

Most commonly used is the platinum 100 ohm RTD because of their stability in air and linearity. Their resistance is 100 ohms @ 0 Deg.C and increases with temperature.

Theory of RTD OperationCommon terms associated with RTD’s are temperature coefficient or alpha, and tolerance class.

Alpha is ohms per ohm per Deg.C.
The average resistance change per unit of temperature from boiling point to ice point of water:

  • Rboiling – Rice point/100deg/100ohms
  • 138.5 – 100.0/100/100 = .00385

Tolerance class is the amount an RTD will differ from the standard resistance curve per Deg.C.

  • Class A (+/- .15 + .002*t)
  • @ temp of 100DegC = +/- .35DegC

When ordering an RTD, a tolerance class will be part of the order, dependent on the application. IEC 751 stipulates that the RTD be marked with their nominal R0 value, their tolerance class, the wiring configuration and the temperature range.
Theory of RTD Operation
3-wire configuration

  • Pt100 / A / 3 / -100/+200  = Platinum 100 Ohm / Class A / 3-Wire / -100 to +200 Deg.C
The most common RTD configuration is the 3-wire type. This configuration is more than adequate for 99.9% of applications. If absolute accuracy is needed, a fourth wire can be introduced, but rarely is it worth the added cost.
Theory of RTD Operation
2-wire configuration

Another configuration is a two wire RTD with a stand-alone loop. (Probably rarely used today).

Since the RTD is a resistance device, the resistance of the wires used to connect the RTD to the measurement meter introduces errors and must be known. This is the reason a third (or fourth), wire is used.

Theory of RTD Operation
3rd wire used to cancel wire error
First the meter reads the resistance of the two common wires to determine the value of Rwire. For a three wire RTD, it is assumed that this resistance is the same as that of one common and one non-common wire.

Then the meter reads the resistance of one of the common wires, the RTD, and the non-common wire to determine Rtotal

Theory of RTD Operation
Meter reading 2 common wires
Meter electronics and software then subtract Rwire from Rtotal to get Rt which is then converted to a temperature.

Theory of RTD Operation

Rt = Rtotal – Rwire

Friday, February 15, 2019

Temperature Sensing IS Rocket Science

Duro-Sense Corporation provides the precision temperature sensors to the aerospace, aviation, and space industries. Duro-Sense engineers bring proven solutions to your most difficult problems. Their R&D department is staffed with some of the industry's most qualified people, working in the most modern facilities to help advance the state of the art in temperature measurement.