Several methods of preliminary judging the performance of temperature and humidity sensors can be used to judge and check the performance of humidity sensors through some simple methods when the calibration of humidity sensors is difficult.
Before we know the performance of temperature and humidity sensors, let's review them briefly.
The concept of temperature and humidity:
Temperature is the physical quantity of heat and cold. In production and scientific research, many physical phenomena and chemical processes are carried out at a certain temperature. The less water vapor in a certain volume of air at a certain temperature, the drier the air; the more moisture the air is, the more humid the air is. The degree of dryness of the air is called "humidity." there are relative humidity, absolute humidity, and dew point in the expression of humidity. The ratio of moisture to dry gas (weight or volume) and so on. The most commonly used physical quantity of humidity in daily life is the relative humidity of air. Expressed in RH, the relative humidity and temperature are closely related to the derivation of physical quantities. A certain volume of airtight gas, The higher the temperature, the lower the relative humidity, the lower the temperature, the higher the relative humidity.
With the rapid development of economy, aerospace, agriculture, machine room, textile, HVAC, scientific research, electric power and other fields, the demand for temperature and humidity sensors is increasing, and the quality requirements for temperature and humidity sensors are becoming higher and higher. The control of environmental temperature and humidity and the monitoring and analysis of moisture content of industrial materials have become one of the most common technical conditions. So how to judge the performance of temperature and humidity sensor and how to select the high quality temperature and humidity sensor?
The following Guangzhou Aosong Electronics Co., Ltd. for you a brief introduction, the content is for reference only.
1. Switch comparison. Test the temperature and humidity sensors in open and closed case, observe their thermal effects and see if they are consistent
2. Comparison of the same kind. It is best to buy two or more sensors of the same type, the same manufacturer's temperature and humidity sensors, and put them together to test the output values under relatively stable conditions. Observe and test their consistency. If you want more accurate answers, you can further test, record the test results at intervals of 24 hours, generally have high, medium and low temperature and humidity conditions within a day. The consistency and stability of the product, including temperature compensation characteristics, can be observed comprehensively.
3. The "dummy method". Humidifying the temperature and humidity sensor with mouth gas or other humidification methods, observing its sensitivity, repeatability, humidity and dehumidification performance, resolution, maximum range of the product, etc.
4. High and low comparison. The product is tested in high and low temperature state (according to the standard in the manual), and is returned to normal condition to compare with the record before the test, to examine the temperature adaptability of the product, Finally, the performance of the product should be based on the standard and complete testing methods of the quality inspection department. The product nameplate can also be used for comparison and inspection by using saturated salt solution as calibration.
Of course, the temperature and humidity sensor we purchased should be calibrated for a long time in order to judge the quality of the humidity sensor more comprehensively. The above is the method of judging the performance of temperature and humidity sensor provided by Guangzhou Aosong Electronics Co., Ltd.