- Industry: Mining
- Number of terms: 33118
- Number of blossaries: 0
- Company Profile:
The U.S. Bureau of Mines (USBM) was the primary United States Government agency conducting scientific research and disseminating information on the extraction, processing, use, and conservation of mineral resources.
Founded on May 16, 1910, through the Organic Act (Public Law 179), USBM's missions ...
An instrument for observing the behavior of roof strata and supports. The device is inserted in 4-ft (1.2-m) long 1-1/2-in (3.8-cm) diameter holes, drilled at selected points, for listening to subaudible vibrations which are known to precede rock failure.
Industry:Mining
An instrument for obtaining information regarding the number of particles present in unit volume of a dust cloud, together with their size distribution. This is probably the most efficient instrument used for dust counts since its efficiency is practically 100% for all particles from 0.2 to 10 mu m in diameter.
Industry:Mining
An instrument for plotting the perimeter profile of an airway on a reduced scale, and primarily used when taking air measurements underground.
Industry:Mining
An instrument for producing and measuring, usually by electrical means, a mass spectrum. It is esp. useful for determining molecular weights and relative abundances of isotopes within a compound.
Industry:Mining
An instrument for recording the ground vibrations caused by heavy quarry blasts. The relationship between the amount of vibration, the distance from the blast, and the weight of explosive fired may be expressed thus: A = (KE)/D, where A = maximum amplitude in thousandths of an inch; K = constant depending on the quarry site; E = weight of explosive in pounds; and D = distance in feet. The constant K can be determined by firing a specimen blast of a given size at a given distance and measuring the amplitude of the record obtained. Amplitudes in excess of 0.04 in (1 mm) may give rise to damage. A movement of 0.008 in (0.2 mm) can be felt, and if used an excessive number of times may give rise to complaints of nuisance and damage. Short-delay blasting methods with small diameter holes reduce vibration hazards.
Industry:Mining
An instrument for registering the maximum pressure occurring during an explosion at the point where the instrument is located.
Industry:Mining
An instrument for regulating the time of burning of a fuse by removing a certain portion of the composition. It has a movable graduated scale that regulates the depth to which the auger should penetrate.
Industry:Mining
An instrument for sampling airborne dust consisting of a wide horizontal duct through which mine air enters in a streamline flow, so that dust particles will be deposited on the duct floor according to their falling speeds as derived from Stokes' law. The instrument combines the duties of monitoring and measuring airborne dust concentrations in mine roadways.
Industry:Mining
An instrument for showing visual representations of electrical outputs from measuring devices.
Industry:Mining
An instrument for testing the density of gases. It consists of a thin glass globe, which is weighed in the gas or gases under observation, and then in an atmosphere of known density.
Industry:Mining
