Calibration and testing of humidity in temperature and humidity sensors - News - Global IC Trade Starts Here Free

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There are two methods for calibrating and testing the humidity in a temperature and humidity sensor, using a humidity reference or comparing it to a known performance instrument. The humidity reference can be established using a thione or potassium hydride solution, or using a saturated salt solution. set up. In the case of control technology, in any case, it must be noted that the selected container printing solution containing the air sample should have a good seal. It is not allowed to change its temperature, and it takes enough time to reach equilibrium. In some cases, the actual balancing time is very long, however, the use of an air pump to draw air from the container portion and cause air to bubble through the solution can significantly shorten the balancing process.
Regardless of the method used, it is always good to have a separate method of measuring these reference humidity, ie, using this single method with only moderate accuracy, it also indicates when equilibrium has been reached and more serious errors are avoided. . Or the main limitation of using this form of humidity reference is that they cannot be used to test or calibrate these sensors without causing serious errors. These sensors can change the local environment by absorbing moisture or evaporating moisture (such as a dew point meter or wet and dry meter) or by introducing a temperature gradient (such as a chloride button or dew point meter). For accurate measurement, this method requires an appropriate amount of air flow.
The most reliable way to calibrate any type of sensor is to compare it to a known good instrument under actual humidity conditions. The relative humidity in the range of 50 to 90% is usually found between noon and midnight in summer, while another method For example, water spray continuously flowing in a bathroom can be used in a high temperature range, and a relative humidity of 50% or less may be obtained in a central heating chamber or may be manually manufactured indoors using an electric heater. The relative humidity in the room is usually 60% at 20 ° C, the temperature is raised to 32 ° C, and the relative humidity can be reduced to 3096. The best instruments used as moisture reference are wet and dry meters and dew point meters. The dew point meter has an accurately calibrated thermometer that is as accurate as the air temperature measurement, so it gives a reliable humidity value, at the expense of high prices. Asman ventilated wet and dry watch is the ideal instrument, and for most purposes, the rotary wet and dry watch is also an accurate enough instrument. Many people agree to use a simple rotary wet and dry watch as a basic standard humidity instrument. Test and calibrate other more specialized instruments against it.