MICROWEIGHING GOES ON LINE IN REAL TIME.

The standard technique for measuring particulate concentrations in industrial processing or field monitoring is based on filter sampling, and the information obtained does not show short-term variations in particulate concentrations. The new balance designed monitors particulates as they are sampled, in real time, on site, and on line. What evolved was a hollow, tapered element with the wide end fixed and the narrow end holding a disc-like filter cartridge. For mass determination, the device makes use of the resonant frequency of the hollow, tapered element in a clamped-free mode. The filter collects particulates from the gas drawn through it, and the filtered gas proceeds through the hollow element. Since the mass of the filter increases as the deposited mass increases, the vibrational frequency of the tapered element decreases according to a formula.