Once warmed up above the response temperature again, the bulb changes irreversibly to a uniform violet color. ColdMark is a tamperproof method of verifying when freeze damage has occurred during shipping, storage or handling, providing a permanent record for quality assurance purposes.
　　该温度标贴能反映出被测物体的温度是否过低,当温度过低时,温度标贴的颜色会改变,即使温度重新升高颜色不会在复原。