ASTM E780

Standard Test Method for Measuring the Insulation Resistance of Mineral-Insulated, Metal-Sheathed Thermocouples and Mineral-Insulated, Metal-Sheathed Cable at Room Temperature

Published by	Publication Date	Number of Pages
ASTM	11/01/2021	5

Category: ASTM

ASTM E780 – Standard Test Method for Measuring the Insulation Resistance of Mineral-Insulated, Metal-Sheathed Thermocouples and Mineral-Insulated, Metal-Sheathed Cable at Room Temperature

1.1”This test method provides the procedures for measuring the room temperature electrical insulation resistance between the thermoelements and between the thermoelements and the sheath, of a mineral-insulated, metal-sheathed (MIMS) thermocouple or mineral-insulated, metal-sheathed (MIMS) thermocouple cable or between the conductors and between the conductors and the sheath, of mineral-insulated, metal-sheathed (MIMS) cable used for industrial resistance thermometers. It may be used to measure the insulation resistance of bulk lengths of mineral-insulated, metal-sheathed MIMS cable previously sealed against moisture intrusion or to test a thermocouple having an ungrounded measuring junction. This method cannot be used to test a thermocouple having a grounded measuring junction unless the measuring junction is removed prior to testing, after which the thermocouple may be dealt with in the same manner as a mineral-insulated, metal-sheathed (MIMS) cable.