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Technical Resources

Articles, tools, and product documentation for specifying platinum resistance temperature detectors.

Technical Articles

IEC 60751 Explained

What IEC 60751:2022 actually specifies for Pt100 sensors: the Callendar-Van Dusen equation, tolerance classes AA to C with their ranges of validity for wire-wound and film elements, the new "-sp" marking system, and what a fractional "1/10 DIN" tolerance really promises.

Article · 8 min read Read the Article

What is Alpha (α)?

The temperature coefficient of platinum resistance sensors: how α = 3.851 × 10⁻³ °C⁻¹ is defined and calculated under IEC 60751, why the industrial value is deliberately lower than pure platinum, and the legacy curves — including the JPt100 — still encountered in the field.

Article · 6 min read Read the Article

Why Wire Wound?

Wire-wound and film platinum sensors compared honestly: the partially supported coil construction used in standard thermometers, the wider IEC 60751 validity ranges wound elements carry in every tolerance class, a fair account of what film sensors do well, and where each technology is the right choice.

Article · 6 min read Read the Article

Tools

RTD Element Tolerance Calculator

Calculate the nominal resistance of a Pt25, Pt100 or Pt1000 element at any temperature, check the permitted tolerance for each IEC 60751:2022 element class (W 0.1 to W 0.6, F 0.1 to F 0.6), and grade a measured resistance against the classes and their ranges of validity.

Interactive tool Open the Calculator

Product Support

Frequently Asked Questions

Answers about what TDI manufactures, detector tolerances, finished-thermometer responsibilities, prototype quantities, production orders and delivery planning.

Product and ordering guidance Read the FAQs

Catalogue and Brochure

Catalogue

Explore Thermal Developments International's full range of high-performance platinum resistance thermometers and sensors, including detailed specifications, construction options, and tolerance classes for industrial and laboratory applications.

PDF · 1.7 MB Download

Brochure

A practical reference to Thermal Developments International's resistance thermometer assemblies — covering construction types, lead options, tolerance classes, and application guidance for high-accuracy industrial and laboratory use.

PDF · 700 KB Download

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