Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Visual performance for incandescent and solid-state cap lamps in an underground mining environment.

Sammarco-JJ; Lutz-T
IAS '07: Conference Record of the 2007 IEEE Industry Applications Conference: Forty-second IAS Annual Meeting, September 23-27, 2007, New Orleans, Louisiana. Piscataway, NJ: Institute of Electrical and Electronics Engineers, 2007 Sep; 4:2090-2095
Miners depend most heavily on visual cues to recognize underground mining hazards; consequently, illumination plays a critical role in miners' safety. Some hazards are located in the miners' peripheral field-of-view (10 degrees to about 60 degrees off-axis) or on-axis (0 degrees). The objective of this research was to determine if there were visual performance improvements when using solid-state cap lamps with light emitting diodes (LEDs) as compared to incandescent light bulbs commonly used in miner cap lamps. Recent research has indicated that an increased short-wavelength content of the spectral power distribution of LEDs relative to incandescent lamps improves peripheral visual performance for low-light (mesopic) conditions. The visual performances of nine subjects were quantified by measuring the subjects' speed and accuracy in detecting floor objects located on axis and at 20 degrees off axis. The objects were located near field (1.83 meters) and far field (3.66 meters). Upon presentation of the objects, subjects would count and point to each object using a red-laser pointer. The object detection response time and number of missed objects were recorded. The results of the visual performance comparison for an LED, a prototype LED, and an incandescent cap lamp are presented. There were no missed objects when subjects used the LED-based cap lamps but, there were three missed object occurrences when subjects used the incandescent cap lamp. The mean detection time when using the incandescent cap lamp was 55.3% greater than the prototype LED cap lamp and 43.5% greater than the LED cap lamp. It can be inferred from this data that the spectral distribution of LED-based cap lamps could enable significant visual performance improvements as compared to incandescent cap lamps.
Mining-industry; Mining-equipment; Light-source; Lighting-systems; Underground-mining; Visual-fields
National Institute for Occupational Safety and Health, 626 Cochrans Mill Road, PO Box 18070, Pittsburgh, PA 15236
Publication Date
Document Type
Conference/Symposia Proceedings
Email Address;
Fiscal Year
NTIS Accession No.
NTIS Price
NIOSH Division
Source Name
IAS '07: Conference Record of the 2007 IEEE Industry Applications Conference: Forty-second IAS Annual Meeting, September 23-27, 2007, New Orleans, Louisiana