4.1 This specification is written to provide common terminology, resistance versus temperature characteristics, accuracy classification, and inspection requirements for a specified configuration of a typical industrial platinum resistance thermometer (PRT).

4.2 This specification may be used as part of the documentation to support negotiations for the purchase and discussion of such thermometers.

This specification establishes the physical, performance, and testing requirements, as well as resistance-temperature relationship and tolerances for metal-sheathed industrial platinum resistance thermometers (PRT) suitable for direct immersion temperature measurement. All materials including the sheath materials, sensing elements, insulation, connecting wire end closure materials, epoxy materials, and connecting wires shall be in accordance with specified requirements. The PRT shall be subjected to corresponding qualification tests to demonstrate conformance to the acceptance criteria of the following properties: insulation resistance; resistance versus temperature; minimum immersion length; pressure; thermal response time; vibration; self-heating; stability; thermoelectric effect; mechanical shock; and dimensions.

1.1 This specification covers the requirements for metal-sheathed industrial platinum resistance thermometers (PRT's) suitable for direct immersion temperature measurement. It applies to PRT's with an average temperature coefficient of resistance between 0 and 100 °C of 0.385 %/°C and nominal resistance at 0 °C of 100 Ω or other specified value. This specification covers PRT's suitable for all or part of the temperature range −200 to 650 °C. The resistance-temperature relationship and tolerances are specified as well as physical, performance, and testing requirements.

1.2 The values of temperature in this specification are based on the International Temperature Scale of 1990 (ITS-90).2

1.3 The values stated in inch-pound units or SI (metric) units may be regarded separately as standard. The values stated in each system are not exact equivalents, and each system shall be independent of the other.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.