The water content in pulverized coal is generally evaluated by using water content with air drying basis Mad.In view of the water content varies as the air temperature and humidity being changed in the case of coal sample preparation

leading to comparative large difference existing in evaluation of water content of pulverized coal

thereby affecting accurate calculation of the dry output capcity for the coal mill.Through changing the test condition

i.e.temperature and humidity of air

a part of fuel coal used in domestic power plants has been tested and studied

the regularity of Mad variation for different coal sorts under different test condition being obtained.The preparation of coal sample with air drying basis under specially defined temperature and humidity condition has been put forward

so as to obtain the accurate water content.