Abstract
The findings have been expounded of the theoretical research aimed at the disclosure of the precise impact of the wear of the mechanical classifier spiral's working parts on the measurement accuracy of the amount of sand in the inter-turn space based on the sand body height. It has been demonstrated that the wear of the spiral's working parts affects both the amount of sand at a certain value of the height of its body and the measurement accuracy of the height itself, with the measurement conducted by the locating method. At a certain constant height of the sand body, less sand is accommodated in the spiral inter-turn space when the operational wear of the working parts is observed, and that “less” can amount to up to 30%. As a result of the working parts' allowable operational wear, the sand body height measurement vertical line coordinates change leading to a relative systemic error, which can reach 20%. That does not make it possible to directly measure the amount of sand in the inter-turn space based on the height of the sand body. The approaches developed make it possible to neutralize the relative sand body height measurement error and to ensure the determination of the amount of sand based on the height of its body with an error not exceeding the process requirements for that parameter's monitoring accuracy.