This method is suitable for the determination of the fineness for dustable and wettable powders of pesticides.
2 Determination method
2.1 Dry sieving method (applicable to dustable powders)
2.1.1 Method summary: dry the sample to constant weight in an oven, naturally cool it to room temperature, weigh the sample after it reaches the humidity balance with the atmosphere, sieve the sample to the end point with a test sieve with appropriate pore diameter, weigh the residue in the sieve, and calculate the fineness (if the dried sample is easy to absorb moisture, the sample shall be cooled in a desiccator and not be exposed in atmospheric environment as possible, then complete sieving of the sample).
2.1.2 Apparatus
Test sieve: with appropriate pore diameter and self-contained receiving plate and cover;
Glass dish: the mass is known;
Brush: 2.5cm soft flat brush;
Constant temperature oven: with temperature control accuracy of ± 2℃ when lower than 100℃;
Desiccator.
2.1.3 Determination procedures
2.1.3.1 Sample preparation
According to the characteristics of the sample, adjust the oven to an appropriate temperature, put enough samples in the oven and dry to constant weight, then naturally cool the samples to room temperature and reach balance with atmospheric humidity for standby.
1 Application scope
This method is suitable for the determination of the fineness for dustable and wettable powders of pesticides.
2 Determination method
2.1 Dry sieving method (applicable to dustable powders)
2.1.1 Method summary: dry the sample to constant weight in an oven, naturally cool it to room temperature, weigh the sample after it reaches the humidity balance with the atmosphere, sieve the sample to the end point with a test sieve with appropriate pore diameter, weigh the residue in the sieve, and calculate the fineness (if the dried sample is easy to absorb moisture, the sample shall be cooled in a desiccator and not be exposed in atmospheric environment as possible, then complete sieving of the sample).
2.1.2 Apparatus
Test sieve: with appropriate pore diameter and self-contained receiving plate and cover;
Glass dish: the mass is known;
Brush: 2.5cm soft flat brush;
Constant temperature oven: with temperature control accuracy of ± 2℃ when lower than 100℃;
Desiccator.
2.1.3 Determination procedures
2.1.3.1 Sample preparation
According to the characteristics of the sample, adjust the oven to an appropriate temperature, put enough samples in the oven and dry to constant weight, then naturally cool the samples to room temperature and reach balance with atmospheric humidity for standby.
