How to conduct research on medical infrared thermometers and temperature compensation technology
Infrared temperature measurement is currently one of the most important non-contact temperature measurement methods. It has the advantages of fast response speed, wide measurement range and high sensitivity, so it is widely used in various industries. When the infrared thermometer is used for body temperature detection, its measurement temperature range should be between 24.0℃ and 45.0℃, and the accuracy requirement is ±0. 1℃. However, even if the currently used infrared thermometer has an accuracy index of 1%, it is far from meeting the accuracy requirements for measuring body temperature. In addition, within the temperature range of 24.0°C to 45.0°C, the measurement accuracy of the infrared thermometer is easily affected by the external ambient temperature, causing its measurement error to increase. At the same time, the accuracy and stability of infrared thermometers are easily affected by the external ambient temperature. Therefore, it is of great significance to reduce the impact of external environmental factors on infrared thermometers.
This topic aims at the current status of medical infrared thermometers and proposes a new ambient temperature compensation method based on a review of a large number of domestic and foreign literature. This method is based on the working principle of the pyroelectric detector, using the difference between the measured object and the ambient temperature as a reference quantity, and determining the amount of compensation based on the difference. Through digital temperature measurement: the ambient temperature is measured using a chip and software compensation is used to avoid the shortcomings of the thermistor used in the past.
In the infrared temperature measurement system, the infrared signal is converted into a pulse signal with a frequency of 20 Hz after being converged by the optical system, modulated by the chopper, and received by the pyroelectric detector. This signal is amplified, filtered, shaped and A/D converted into a digital signal, and then sent to the microcontroller for data processing, compensation and display.
In the system design process, the Wave6000 microcontroller simulation system is used to debug the microcontroller. In order to maintain the correct timing relationship between various parts, the software is all written in assembly language. Calibration and testing of the system show that the system has improved measurement accuracy and stability.
