The bimetallic thermometer detection rules

1, scope of application: applicable to the measurement range in ‐ 80 ten 500 ℃, composed of double metal components and sheath temperature detecting element and a circular dial bimetallic thermometer ( Hereinafter referred to as the thermometer) The inspection. 2, the rules: references JJG 226 - The bimetallic thermometer verification regulation of 2001. 3, concept: bimetallic thermometer with different expansion coefficient of two kinds of metals ( Or alloy) Piece together form a thermal components, generally made spiral wound, its one end fixed and the other end ( The free end) Equipped with a pointer. When the temperature changes, the thermal component of curvature change, free end rotation, drive the pointer indicates the temperature value on the dial. 4, level and the maximum permissible error: accuracy level of the accuracy of the thermometer and the maximum permissible error ( Allowed error limits) Should comply with the provisions of the table 1. Allowable error (accuracy degree, Range of %) ℃ accuracy degree maximum allowable error ( Range of %) ℃1. 01. 52. 0± 1. 0± 1. 5± 2. 02. 54. 0± 2. 5± 4. Poor 0 table 15, back to the back of the thermometer should not be greater than the maximum permissible error of the absolute value. 6, repeatability: the repeatability of the thermometer should be not more than half of the maximum permissible error absolute value. July 7, general technical requirements. 1 7 appearance. 1. 1 thermometer components assembly wants firm, shall not be loose, can not have corrosion, cases should be strong, uniform and smooth. 7. 1. 2 thermometer used in the header should be transparent glass or other transparent material, can not have interfere with the correct reading of 7 defects or damage. 1. 3 thermometer scribed line on the dial, Numbers, and other marks shall be complete, clear and correct. 7. 1. 4 pointer thermometer should cover ( Stretch) A quarter - the shortest dividing line Three quarters. Pointer indicating the width should not be more than the shortest dividing line width. 7. 1. 5 pointer thermometer and the distance between the dial surface should be not more than 5 m, but should not touch the dial. 8, measuring instruments, control: 8. Standard 1: check the standard according to the measuring range of the thermometer can choose second-class standard mercury temperature 8, respectively. 2 testing equipment: as shown in table 2 thermostat name using temperature range cryogenic tank - alcohol 30 - 20 ℃ constant temperature water trough at room temperature 100-95 ℃ constant temperature tank 200-200 ℃ temperature salt bath 300 ℃ table 29, testing record: fill in the inspection records.