Method Factors for Anemometer Measurement At Pipe Outlets.
Proc Longwall U S A Conf Pittsburgh, Pennsylvania, 6/2-4/87 PP 125-134 :125-134
This paper discusses vertical gob holes routinely used to control methane in gobs. In most cases, vane anemometers are used to measure the velocity of gas flowing from the gob holes and subsequently to calculate the volume flow of gas. Generally, the anemometer is centered on the end of the pipe during the measurement. If the cross section of the anemometer is appreciably larger than one-sixth of the pipe diameter, then erroneous velocity readings occur, owing to the blocking effect of the instrument.
Proc. Longwall U.S.A. Conf. (Pittsburgh, Pennsylvania, 6/2-4/87) PP. 125-134