Air survey

AIR SURVEY (EN: air distribution measurements; DE: Messungen der Wetterverteilung; FR: mesures de la distribution d'air; ES: mediciones de la distribucion del aire; RU: воздушная съемка) is the complex of the works for the determination of the character of the distribution of the air within the mine workings of the underground mine (or of the part of this underground mine). The air survey comprises the measurements of the speed of the air, and of the area of the cross-section of the mine workings, with the subsequent computation of the expenditure of the air, and with the compilation of the balance for this expenditure of the air. For the increasing of the accuracy of the air survey, they additionally measure the pressure of the air, and the temperature of the air. They choose the points for the measurements during the air survey with such intention, as to determine the expenditures of the incoming and outgoing air for the underground mine as a whole, and for the individual objects of the airing (places, cleaning and preparatory mine workings, chambers, layers, wings, and so on), and also to determine the leakages of the air.

During the compilation of the balance, the total expenditure of the air, which is incoming into the underground mine, must coincide with the sum of the expenditures of the air within the individual ventilation streams. Practically, there emerges the difference between these expenditures, the magnitude of which may be decreased on the account of the decreasing of the duration of the air survey, on the account of the performance of the simultaneous measurements, and on the account of the normalization of the expenditures of the air to the unified conditions of the temperature and pressure. The total magnitude of the difference is distributed throughout all the individual ventilation streams proportionally to the expenditure of the air, which is passing within these streams. The air survey is the constituting part of the depression survey, and of the gas survey.