C. Analysis of Bulk Density Affection Test
Fig.9 shows the data of peat and vinegar residue under
different bulk density. All data were processed by least square
method to fit parameter β, where U2 was taken as average
output voltage when the water content was 0, then draw the
fitting curve and move it up and down with 0.025 units,
respectively. Fig.9 shows all data fall between the up and down
translation curve, it indicates that the bulk density affection on
moisture measurement is less than 0.025.