Views: 30 Author: Site Editor Publish Time: 2020-08-06 Origin: Site
The difference between temperature humidity calibration test chamber and others
LIB calibration test chamber is very similar to the conventional benchtop temperature and humidity test chamber. The biggest difference is that the humidity sensor uses a capacitive sensor, which has higher accuracy than conventional sensors. The variation of the capacitance sensor is: T: 0~120°C, RH: 0~100% RH. If the test of a test chamber requires temperature and humidity within this range, the test chamber only needs a capacitance sensor, which detects both temperature and humidity. If the test temperature and humidity requirements exceed this ratio, the calibration test chamber needs to be equipped with a PT-100A to detect temperature and a capacitance sensor to detect humidity.
The importance of calibration
The test products are samples of instruments, such as thermometers and hygrometers, and meters need to be calibrated and tested to fully ensure their accuracy. Laboratory accreditations like ISO 17025 have very specific requirements, one of which is that anything expressed as “calibration” must strictly adhere to the definition of calibration, that is, comparison with known reference standards. In addition, this comparison must usually be "metrically traceable." In the United States, this traceability can usually be traced back to the National Institute of Standards and Technology (NIST) measurement standards, called "NIST traceability."
Calibration involves comparing the measurement system with known measurement standards. There is a certain difference between calibration and adjustment. When the appropriate term is "adjustment", please be careful to use the term "calibration" because the difference between the terms is important for auditing and traceability.
What parameters need to be calibrated?
The temperature and humidity series of environmental test chambers mainly calibrate the uniformity, deviation, fluctuation, heating rate and cooling rate of temperature and humidity;
The salt spray corrosion test chambers need to calibrate the amount of salt spray deposition, as well as the uniformity, fluctuation and deviation of temperature and humidity;
The xenon lamp aging test chambers need to calibrate the size of the radiation, the blackboard temperature and the deviation of the indoor temperature, and the relative humidity;
The sand and dust test chambers need to calibrate the deviation of temperature and humidity.
Measurement items of temperature and humidity calibration
The measurement items of the temperature and humidity calibration test chamber generally include temperature, humidity, volatility, temperature uniformity, humidity uniformity, temperature, and humidity deviation. Volatility refers to the change of the central parameter of the working space with time under the steady state of the environmental test equipment. Uniformity refers to the difference (temperature and humidity) between a certain point in the working space and the test point when the environmental test equipment is in a stable state. Deviation refers to the measured peak value and the upper and lower nominal value and the smallest deviation of the environmental test equipment in the steady state of the working space.
According to the actual needs of the measurement range, select the appropriate instrument to measure the temperature and humidity of each item. The arrangement of the measuring test points of the instrument Whether the arrangement of the measuring test points of the temperature and humidity test chamber is correct, directly affects the accuracy of the measuring results of the instrument. The temperature and humidity test chamber shall at least include temperature and humidity measurement items. The layout of temperature measurement test points and humidity measurement test points is also very particular.