Definition
ISO scraper fineness meter is a physical measuring instrument designed according to the relevant standards of the International Organization for Standardization, which is mainly used to evaluate the dispersion degree or particle size distribution of solid particles in liquid systems. It indirectly characterizes the fineness level of a sample by measuring the depth of particle appearance in the scraper groove under specific conditions. The instrument has a wide range of application bases in quality control in industrial fields such as coatings, inks, chemical raw materials and ceramic pastes.
Principle
The working principle of ISO scraper fineness meter is based on the geometric structure and optical judgment of scraper and groove. The body of the instrument is a finished stainless steel plate with one or several precision grooves with a specific depth gradient engraved on it. During the test, an appropriate amount of sample is placed at the deeper end of the trench and scraped along the length of the trench at a constant speed and pressure using a matching scraper. After scraping, due to the influence of solid particle size, the particles will show obvious traces at the groove depth comparable to their size. The observer identifies the scale position where the particles appear uniformly by the naked eye or auxiliary optical equipment, and the groove depth value corresponding to this position is the fineness reading of the sample, usually expressed in microns.
Measurement method
The measurement process follows standardized operating procedures to ensure comparable results. First, the instrument and the sample to be tested are placed in a standard test temperature environment. Before sampling, the sample should be thoroughly stirred well, and then a small amount of sample drops should be added to the starting end of the scraper groove. Subsequently, hold the scraper perpendicular to the plate surface and scrape the sample across the entire trench area at a steady speed within 1 to 2 seconds. After the scraping action, the position of the particles in the groove should be checked within a few seconds under standard light source conditions at a certain observation angle. The scale value corresponding to this position is the measurement result. Multiple parallel measurements are recommended for each sample to obtain representative data.
Influencing factors
The accuracy of measurement results is affected by a combination of factors. The rheological properties of the sample, such as viscosity and thixotropy, can affect the distribution and arrangement of particles during scraping. Environmental conditions, particularly temperature and humidity, can alter the physical state of the sample. Consistency in operation is crucial, including the speed, angle, and pressure applied to the scraping. The wear of the scraper and plate can also directly affect the actual depth and profile of the trench. In addition, the subjective judgment of the observer, especially in the determination of the particle appearance point, can introduce bias. Therefore, strict environmental control, standardized operation training and regular calibration of instruments are important links to ensure measurement reliability.
Application:
The application of ISO scraper fineness meter runs through the R&D and production quality control links of multiple industries. In the coatings industry, it is used to evaluate the dispersion quality of pigments and fillers in paints, which has a direct impact on the gloss, color, and durability of coatings. The ink industry relies on it to control pigment particle fineness to ensure clarity and color saturation in prints. In fields such as electronic pastes, ceramic glazes, and cosmetic raw materials, this instrument is used to monitor the particle size distribution of solid particles in slurries or pastes to ensure the stability of product performance and smooth processing processes. As a fast and easy means of offline inspection, it provides instant feedback for parameter adjustment during production.
Selection
When choosing a suitable scraper fineness meter, it is necessary to take into account the measurement range, accuracy requirements and standards to be followed. First, a suitable trench depth range should be selected according to the expected fineness range of the sample to be tested, and the common range covers 0 to 25 microns, 0 to 50 microns, 0 to 100 microns and wider ranges. Secondly, it is necessary to confirm whether the instrument meets the specific standard version recognized by the target market or industry, for example, different revisions of ISO standards may have subtle regulations on groove size and scraper material. The material and manufacturing process of the instrument affect its durability and measurement stability, with high-hardness stainless steel bodies and precision-ground grooves being common requirements. In addition, consider whether it is necessary to match auxiliary equipment such as standard light sources or reading magnifying glasses to reduce human observation errors. The final selection should be based on the actual testing needs, standard compliance and long-term reliability.