When the non-contact infrared thermometer is measuring, Why can't there be obstructions on the forehead ?
The main reason is that if you have obstruction, when you measure the forehead you're measuring the temperature of it, which makes the measurement inaccurate. But as the technology improves, the infrared thermometer will display a red screen that tells you to clean the obstructions.
The temperature error measured by the infrared thermometer is usually about 0.1-0.2℃.
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