Last data update: Jun 17, 2024. (Total: 47034 publications since 2009)
Records 1-3 (of 3 Records) |
Query Trace: Martell MJ [original query] |
---|
Effects of light spectrum on luminance measurements in underground coal mines
Martell MJ , Sammarco J , Macdonald B . IEEE Trans Ind Appl 2019 55 (6) Lighting regulations for luminance in U. S. coal mines are verified in the field by using a luminance photometer calibrated to the Standard Illuminant A light source. Significant measurement errors can exist when measuring light sources that are dissimilar to light sources used to calibrate the photometer. This paper quantifies the measurement errors when measuring these dissimilar light sources commonly used in U.S. underground coal mines-an LED, a CFL with a clear cover, a CFL with an amber cover, and a tungsten halogen. The impact of photometer quality was also evaluated. Three different luminance measuring instruments of high, medium, and low quality were compared-a PR-650, LS-100, and PMEX, respectively. The PMEX was under evaluation for measuring luminance compliance in U.S. underground coal mines. The PR-650 was used as the referent to which the other photometers were compared. The PMEX error ranged from -17.0% to -26.5% with the highest error for the amber CFL. The LS-100 closely matched the luminance measurement for the LED and halogen; however, it had a percent error of -10.4% for the amber CFL. After the initial experiment, MSHA made improvements to the PMEX resulting in the PMEX-MSHA. The experiment was replicated using the new photometer and the newer PR-670. After repeating the experiment, the measurement errors ranged from -16% to -19% for the PMEX-MSHA, thus indicating an improvement over the PMEX. These results show that the spectral content of a light source and the photometer quality can greatly impact the accuracy of luminance measurement. |
Detectability of a self-illuminating lifeline for self-escape in smoke conditions of an underground mine
Martell MJ , Sammarco JJ , Macdonald B , Rubinstein E . Light Res Technol 2019 52 (1) 64-78 Lifelines are used to aid self-escape of underground miners, but they are difficult to find in low-visibility conditions of smoke, therefore a self-illuminating lifeline could facilitate miners in locating the lifeline. The detection distance, colour recognition, and miss rate for 10 subjects were determined for red-, green- and blue-lighted diffuse fibre-optic cables, used to create a lighted lifeline, and a traditional rope lifeline in a smoked-filled environment. The testing was conducted with and without a cap lamp. The use of a cap lamp resulted in all cases being undetected in 98.3% of trials. With the cap lamp off, there was no significant difference in the detection distance for blue- and green-lighted fibres; however, the miss rate for the green-lighted fibre was slightly higher. The red-lighted fibre was not detected in 93.3% of trials. The green- and blue-lighted fibres enabled the best visual performance, but subjects had difficulty correctly identifying the colour of the fibre. The lighted fibre-optic cable appears to have merit for improving self-escape from underground mines, and may have other mining and non-mining applications that include improving self-escape visibility. |
LED lighting for improving trip object detection for a walk-thru roof bolter
Sammarco JJ , Macdonald BD , Demich B , Rubinstein EN , Martell MJ . Light Res Technol 2018 51 (5) 725-741 Proper lighting plays a critical role in enabling miners to detect hazards when operating a roof bolter, one of the most dangerous mining machines to operate; however, there has not been any lighting research to address the walk-thru type of roof bolter commonly used today. To address this, the Saturn light was designed to directly address walk-thru roof bolter safety by improving trip hazard illumination. The visual performances of 30 participants that comprised three age groups were quantified by measuring each participant's visual performance in detecting trip objects positioned on the two floor locations within the machine's interior working space. The lighting conditions were the existing compact fluorescent lights (CFLs) and the Saturn LED area light developed by NIOSH researchers. Three intensities of the Saturn lights were used, 100%, 75%, and 50%, all of which resulted in better visual performance, and up to a 48% reduction in average trip detection time compared to the CFL. For the Saturn trip object miss rates were <0.5% for all age groups in contrast to the CFL, which ranged between 32.5% for the youngest group and 50.4% for the oldest group. |
- Page last reviewed:Feb 1, 2024
- Page last updated:Jun 17, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure