NIOSH Mining Laboratory

NIOSH researcher conducting gas content test using the Modified Direct Method apparatus

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The Gas Content Testing Laboratory is designed to conduct in-house gas content testing of coal cores in accordance with NIOSH´s Modified Direct Method (MDM) testing procedure. The portable modified direct method testing apparatus is designed for both laboratory and field use. The Laboratory meets or exceeds the minimum testing requirements of the NIOSH patented MDM testing apparatus and procedure. After coal samples are collected in the field, they are returned to the gas content testing laboratory where sample containers are stored in a stable, temperature controlled environment for the duration of the test. The laboratory includes test benches and storage space for the MDM apparatus and associated equipment and supplies needed to conduct the gas content tests. Two activities related to gas desorption volume monitoring are also performed in the gas content testing laboratory. Coal core sample containers are leak tested in the lab using pressurized gas prior to the sample container going into the field. Pressurized gas is also used in the canister free space determination procedure that is a component of the total gas content calculation method. After the gas desorption volume monitoring of the samples is completed, the coal core samples are crushed in a Siebtechnik puck and ring mill to determine the residual gas content left in the sample. The Siebtechnik puck and ring mill is housed in a separate room within the Gas Content Testing Laboratory.

Site:  Pittsburgh Research Laboratory