Badge-Type Noise Dosimeters Used in the Mining Industry

Currently, a number of manufacturers have developed and made commercially available badge-type (cordless) noise dosimeters. Previous studies conducted by the Mine Safety and Health Administration (MSHA) revealed that microphone size and placement/orientation significantly influence measurement error. The badge-type design houses the microphone within a significantly larger casing than does the traditional corded-type dosimeter. This presents concern that badge-type designs may significantly inhibit measurement accuracy. The purpose of this study is to evaluate the casing of various badge-type dosimeters in order to discern conditions and assess the extent to which the badge-type design contributes toward measurement error in comparison with the traditionally used corded dosimeter. For this, a series of laboratory measurements were conducted employing various commercially available badge-type casings and corded counterparts. Corresponding results are summarized and extended to conclusions regarding the effect of microphone casing design, badge-type versus corded, on measurement accuracy for personal noise dosimetry.