The Role Of NTC Thermistor Inside Temperature Gun Thermopile
March 12, 2020
The pneumonia epidemic caused by the new coronavirus overshadows the Spring Festival of the Gengzi year. In the process of preventing and controlling the new coronavirus epidemic, medical products such as ventilators, monitors, oxygen generators, negative pressure ambulances, and forehead guns have played a significant role. The non-contact temperature measurement method of the forehead gun can avoid contact cross infection and play a convenient and quick role in preventing and controlling the epidemic of the general public.
Forehead guns and ear thermometers use thermopile probe infrared thermometers to measure the radiant energy emitted by an object. According to Boltzmann's law (E = σεTⁿ), the greater the radiant energy, the higher the temperature After transforming the infrared radiation signal into an electrical signal, it can be finally converted into the temperature value of the measured target after being corrected by an amplifier and a signal processing circuit and corrected according to a certain algorithm and target emissivity.
The main device for temperature measurement is the thermopile. A thermopile infrared probe is a temperature sensor consisting of a series of thermocouples connected in series. The two ends of a thermocouple are composed of two different materials. When one end contacts the hot end and the other end contacts the cold end, a potential difference will occur between the two different materials due to the see-beck effect. The magnitude of the potential difference is between the two different materials. The temperature difference is related. A thermopile sensor connects a series of thermocouples in series to increase the detection sensitivity of the sensor.
In order to be able to calculate correctly at different ambient temperatures, a high-precision NTC thermistor is used to measure the ambient temperature of the thermopile. According to some standard temperature conditions written in advance, for example: the temperature of the measured object is 37 ° C, The output temperature of the thermopile is 25 ℃, and the measured temperature is calculated by the output voltage of the thermopile and the absolute temperature of the environment of the thermopile. Uchi MF58 temperature-measuring NTC thermistor 100KΩ3950 is a commonly used specification. There are also use schemes in which chips of this type are used directly and combined with thermopile using a bonding packaging process.
Uchi MF58 temperature-measuring NTC thermistor series products have good stability and high reliability; a wide range of resistance values and high accuracy; small size, light weight, sturdy structure, convenient for automatic installation; fast thermal induction, high sensitivity and other characteristics. MF58 products are widely used in home appliances, office automation equipment temperature detection or temperature compensation, mobile phone batteries, battery packs, instrument coils, integrated circuits, quartz crystal oscillations and thermocouples / thermopiles. Uchi's MF58 products have obtained CQC mark certification, UL, C-UL safety certification, passed the harshest 100,000 durability tests in the UL standard, and passed AEC-Q200 testing, which is unique and reliable in China. Performance, superior quality, trustworthy.