【国外标准】 Standard Test Method for Thermal Shock Resistance of Porcelain-Enameled Utensils

This test method covers the determination of the resistance of porcelain-enameled utensils to thermal shock. A hot plate, timing device, container, and sponge shall be used. The surface temperature of the hot plate, determined by any suitable surface temperature measuring device, may be varied by changing the wattage input to the hot plate. If the hot plate surface temperature be calibrated to wattage input, the desired temperature may then be set by adjusting wattage input. The wattage input or similar calibration shall be made for each surface temperature. In preparation for the test, the hot plate shall be leveled and the surface temperature shall be adjusted to a certain level. Quenching water shall be placed in a large container and its temperature shall be adjusted to a certain level. The amount of water required to fill a test utensil to a certain depth shall be measured. A dry utensil shall be centered directly on the preheated hot plate. After a certain time, the utensil shall be removed from the hot plate and the utensil immediately shall be filled to some depth with quenching water. After a few seconds, the quenching water shall be poured out and the inside of the utensil shall be wiped with a wrung-out damp sponge. After some time, the utensil on the hot plate shall be replaced. Immediately after centering the utensil on the hot plate, the input to the hot plate shall be adjusted so that the hot plate surface temperature will reach a certain level. The utensil shall be allowed to heat dry for a few minutes with the hot plate adjusted so the new surface temperature will be reached. After a certain heating period, the utensil shall be removed. This procedure shall be repeated according to the schedule given. The test shall be continued until the utensil fails or has withstood quenching after a certain heating temperature.1.1 This test method covers the determination of the resistance of porcelain-enameled utensils to thermal shock. This test method is adaptable to any porcelain-enamel utensil that can be filled with water to a depth of 1 in. (25 mm).1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.3 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.1.4 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.