ASTM E780-92(1998)
Historical Standard: ASTM E780-92(1998) Standard Test Method for Measuring the Insulation Resistance of Sheathed Thermocouple Material at Room Temperature
SUPERSEDED (see Active link, below)
ASTM E780
1. Scope
1.1 This test method covers the techniques and requirements for measuring the electrical insulation resistance at room temperature between the thermoelements and between each of the thermoelements and the metal sheath of compacted ceramic-insulated, sheathed thermocouple material. It may be used to measure the insulation resistance of bulk lengths of sheathed thermocouple material environmentally sealed at the time of manufacture. It may also be used for testing sheathed thermocouples with a Type U junction. This test method cannot be used for sheathed thermocouples with a Type G junction unless the junction is removed, prior to testing.
1.2 This test method applies to the testing of sheathed thermocouple materials that are suitable for use in air. It is also applicable for sheathed thermocouple materials whose sheath or thermoelements are composed of refractory metals and are tested in a dry and nonreactive environment.
1.3 This test method may be used for sheathed thermocouple material having an outside diameter of 1.0 mm or larger.
1.4 Since the insulation resistance at room temperature of sheathed thermocouple materials may change during shipment, storage and use, the results obtained by this test method may not be the same as insulation resistance values determined at some later time.
1.5 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
ASTM Standards
E235 Specification for Thermocouples, Sheathed, Type K and Type N, for Nuclear or for Other High-Reliability Applications
E344 Terminology Relating to Thermometry and Hydrometry
E585/E585M Specification for Compacted Mineral-Insulated, Metal-Sheathed, Base Metal Thermocouple Cable
E608/E608M Specification for Mineral-Insulated, Metal-Sheathed Base Metal Thermocouples
E1652 Specification for Magnesium Oxide and Aluminum Oxide Powder and Crushable Insulators Used in the Manufacture of Metal-Sheathed Platinum Resistance Thermometers, Base Metal Thermocouples, and Noble Metal Thermocouples
E2181/E2181M Specification for Compacted Mineral-Insulated, Metal-Sheathed, Noble Metal Thermocouples and Thermocouple Cable
Keywords
insulation resistance; mineral-insulated, metal-sheathed thermocouple cable insulation resistance; mineral-insulated, metal-sheathed thermocouple insulation resistance; Megohmeter test; Sheathed thermocouples; Electrical resistance/resistivity--electrical contact materials; Insulation resistance; Thermocouples; Visual examination ;
ICS Code
ICS Number Code 17.200.20 (Temperature-measuring instruments)
DOI: 10.1520/E0780-92R98
ASTM International is a member of CrossRef.