Wood Moisture Meter Other Methods of Determining Moisture
1. Chemical drying method
The chemical drying method is to put a chemical that has a strong adsorption effect on water vapor and a water sample into a desiccator (glass or vacuum desiccator), and make the sample reach a dry constant weight through isothermal diffusion and adsorption, and then according to The moisture content can be calculated from the weight loss of the sample before and after drying. This method takes a long time to dry at room temperature, several days, dozens of days or even months.
Desiccants include phosphorus pentoxide, barium oxide, magnesium perchlorate, zinc hydroxide, silica gel, chlorine oxide, etc.
2. Microwave method
Microwave refers to electromagnetic waves with a frequency range of 103 to 3×105 MHZ. When microwave passes through a water-containing sample, the energy loss caused by moisture is far greater than the loss caused by dry matter, so the water content of the sample can be obtained by measuring the loss of microwave energy.
3. Infrared absorption spectroscopy
Infrared rays belong to electromagnetic waves, light with a wavelength of 0.75 to 1000 μm. The infrared band can be divided into three parts:
① near infrared region 0.75 ~ 2.5μm;
②Mid-infrared region 2.5～25μm;
③Far infrared region 25～1000μm.
According to the fact that there is a certain relationship between the degree of moisture absorption of infrared light of a certain wavelength and its content in the sample, a method for determining moisture by infrared spectroscopy is established.
