Measurement of Airborne Diesel Particulate in a Coal Mine Using Laser Raman Spectroscopy.
Cornilsen-BC; Johnson-JH; Loyselle-PL; Carlson-DH
NIOSH 1990 Sep:656-662
Laser Raman Quantitative Analysis (LRQA) was evaluated as a method for measuring diesel particulates in the air of underground coal mines. This method could employ the same sampling equipment and techniques used for respirable dust level measurement, did not require transfer of samples between collection and analysis substrates and allowed for further analyses on a sample. Samples were obtained near the feeder breaker, in the return and within 2 feet of the operator on the ram car, using a personal sampler operated at 2 liters per minute flow rate. Filter loadings were aimed at 0.15 milligram per square centimeter (mg/cm2) and actually ranged from 0.07 to 0.4mg/cm2. Diesel only and coal only samples were obtained from tailpipe emissions and the continuous miner scrubber, respectively. LRQA results were compared with estimates from percent carbon-dioxide levels and with results from Micro- Orifice Uniform Deposit Impactor size selective sampling. Coal only and diesel only samples provided identifying intensity ratios for two Raman spectrum bands. Five of 11 filter sets collected at the three sampling locations revealed inhomogeneous deposition of diesel and coal particulates. The larger coal particles tended to deposit toward inner radii of filters. Relative amounts of diesel particulate ranged from 37 to 83%, with respirable levels of 0.18 to 1.61mg/m3. LRQA and size selective sampling demonstrated excellent agreement for two of three duplicate samples; the third set differed by 25% and may have been due to different conditions over the sampling time. The authors conclude that diesel particulate monitoring techniques are important and that increased precision and accuracy of the LRQA method can be achieved by optimization of procedures.
Underground-mining; Analytical-methods; Coal-mining; Analytical-instruments; Diesel-exhausts; Diesel-emissions; Airborne-particles; Spectrographic-analysis;
Proceedings of the VIIth International Pneumoconioses Conference