Humidity measurement

Instruments for monitoring environmental humidity include: temperature and humidity measuring meters, surface pyrometers or optical high temperature, dry hygrometers for measuring dry and wet immersion temperatures, electronic temperature and humidity continuous Recorders, etc. When measuring, the instrument should be installed in the place where the data of hot, cold and average areas are collected, but it should not be installed in direct sunlight, wind, heat radiation, heating or blowing wind pipes or other places that affect the average count.

At present, there are measuring tables for measuring ambient temperature and relative humidity on the market, which can directly measure humidity, and check the intersection point of temperature and humidity in Table 4_5_17 to find out the dew point temperature. The surface temperature of the coated object should be higher than the "dew point" 3 °C before painting.

In the past, wet and dry bulb thermometers were commonly used to measure its temperature and relative humidity. It was composed of two identical thermometers, one of which was wrapped with two layers of gauze (or cotton ball), and the lower end of the gauze was immersed in a small bottle filled with water. The reading of the thermometer was wet. The other thermometer reads the dry bulb temperature. According to the temperature difference between the dry bulb and the wet bulb, find out the relative humidity in the air in the special table.

The temperature and humidity meter adopts the principle of resistance measurement. Although it can read directly, it needs to be placed in the environment to be tested for more than 1 hour. Coatest1600 type dry humidity measuring instrument can read quickly within 1 minute at the construction site, which is suitable for on-site inspection and survey.

When the ambient temperature is 35°C, the steel surface temperature can reach 60~70°C. The surface temperature of the object to be measured is generally measured by a direct-reading thermocouple digital thermometer, and the sensitive probe can be placed directly on the surface for a few minutes. reading.