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On the Measurement Scheme of humidity Sensor

Release Time:2018-01-29 Reading Volume:3

There are two main kinds of modern humidity measurement schemes: wet and dry ball method and electronic humidity sensor method. The following two methods are compared so that the customer can choose their own humidity measurement method.

Characteristics of wet and dry bulb hygrometers:

As early as the 18th century, people invented the wet and dry bulb hygrometer, the accuracy of the wet and dry bulb hygrometer also depends on the accuracy of the dry ball, the wet bulb two thermometers themselves; the hygrometer must be ventilated: only the gauze water jacket, the water quality, The accuracy of the wet and dry bulb hygrometer is only 5% and 7RH. The humidity value is obtained by measuring the dry bulb temperature by the indirect measurement method. Therefore, there are no strict restrictions on the use of temperature, and humidity measurement in high temperature environment will not cause damage to the sensor. The maintenance of the wet and dry ball method is quite simple, and in practical use, All you have to do is regularly add water to the wet bulb and replace the wet ball gauze. Compared with the electronic humidity sensor, the wet and dry ball method does not produce aging. So the wet and dry ball method is more suitable for high temperature and bad environment.

Illumination meter
Noise meter
Radiation meter
Sound level meter
Temperature and humidity meter
Infrared thermometer

Features of electronic humidity sensors:

Electronic humidity sensors have developed rapidly in recent decades, especially in the past 20 years. The accuracy of the electronic humidity sensor can reach 2% ~ 3% RH. in practical use, because of the influence of dust, oil and harmful gas, the aging will occur and the precision will decrease after a long time. The annual drift of the humidity sensor is generally ±2%. In general, the manufacturer indicates that the effective service time for one calibration is one or two years, and the expiration period needs to be re-calibrated. The annual drift of the Othson humidity sensor is within ±1%. Olson Electronics products are calibrated every year. The quality of each product has been guaranteed, and the accuracy level of the electronic humidity sensor must be judged in terms of its long-term stability, generally speaking, The long-term stability and service life of the electronic humidity sensor are not as long as those of the wet and dry bulb humidity sensor. If the product is calibrated and tested every year, the service life and stability of the product can be effectively prolonged.