This report describes the design, development, and manufacture of a monitoring system to continuously monitor the buildup of float coal dust and rock dusting materials in coal mine workings. A readout and special switch module can monitor up to 10 coal dust sensors, displaying the dust load directly in milligrams per square centimeter with a sensitivity of 0.5 Mg/cm2. The readout is a microprocessor-based unit, MSHA approved, and is rugged, portable, accurate, and easy to use and read. The sensors collect dust on a disk and measure the dust loading using vibrating wire technology. Ten dust sensors and two readout and switch station units were built, performance tested, and calibrated. The hardware was delivered to the Bureau of Mines for further evaluation and in-mine testing.