1 Normal Human Body Temperature Medical research hasn't determined an exact correlation between oral, rectal, ear, armpit, and forehead temperature measurements. Generally, the correlation of temperature results are as follows: The average normal oral temperature is 98.6°F (37°C).A rectal temperature is 0.5°F (0.3°C) to 1°F (0.6°C) higher than an oral temperature.An ear (tympanic) temperature is 0.5°F (0.3°C) to 1°F (0.6°C) higher than an oral temperature.An armpit (axillary) temperature is usually 0.5°F (0.3°C) to 1°F (0.6°C) lower than an oral temperature.A forehead (temporal) scanner is usually 0.5°F (0.3°C) to 1°F (0.6°C) lower than an oral temperature.
2 Solution for Infrared Forhead Thermometer
3 Thermopile Sensor
The thermo sensor is the core of the Infrared forhead thermometer scheme. The principle is to utilize the Seebeck effect (also known as the first thermo effect).Generally, the operating temperature and sensitivity of thermopile sensors ranges from 5 ~ 90mV/℃.
4 MCU Processors
Since the sensitivity of thermopile sensor is 5 ~ 90mV/℃, the signal can be detected by MCU's AD and the corresponding temperature can be calculated.(if the sensitivity of the sensor is less than 1mV, it is can be amplified by the precision operational amplifier before being detected by the MCU).
When the human body temperature tested exceeds the normal value (37.3℃), the buzzar will beep indicating that the tested one's temperature is higher than the normal value
6 LED Display
When the temperature data of human body is collected by the sensor, it is transmitted to the MCU for calculation to remove environmental interference, and the collected temperature of human body needs to be displayed through the LCD screen.
7 Solution for PCB Design
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