MSHA Approved Coal Dust Explosibility Meter for Rock Dusting Applications
Measures percent rock dust in coal mine dust samples
Portable direct-reading instrument
Instantaneous explosibility indication
Easy-to-read digital display
MSHA approved (18-A 110002-0)
- Tested and Validated by NIOSH
The Sensidyne CDEM-1000 Coal Dust Explosibility Meter is a portable, handheld, easy-to-use instrument, which is designed to provide a direct indication of the potential explosibility of a coal and rock dust mixture in accordance with Title 30, Code of Federal Regulations, Part 75.403.
The CDEM was tested and validated at the NIOSH Office of Mine Safety and Health Research Laboratory in Pittsburgh. It has an MSHA approval (18-A 110002-0) for use in underground coal mines. The CDEM-1000 meets the needs of mining operators and safety inspectors when following the coal dust sample collection guidelines as described in Bureau of Mines Information Circular I.C. 7113 or MSHA Handbook, Number PH-08-V-1.
Current regulations require the application of inert rock dust in all underground areas of a bituminous coal mine to mitigate the propagation of a coal dust explosion. The CDEM-1000 is intended to be used by mine operators, safety officials and regulators as a screening tool to help manage daily rock dusting operations and to help mitigate the explosion hazard potential by identifying inadequate rock dusting applications. The CDEM-1000 can also be used as an effective tool by mine operators to help determine a more efficient balance between coal dust and rock dust levels.
The operation of the CDEM-1000 is based on the difference in optical reflectance between the darker coal dust and the lighter inert rock dust in band samples taken from the mine surface. The mixture of coal dust and the lighter inert rock dust becomes lighter in color as the concentration of rock dust increases. The higher the concentration of rock dust, the lower the explosion potential of the coal dust mixture. The instrument is intended to be a "go", "no-go" device which displays a ***RED*** indication for insufficient rock dust levels and a ***GREEN*** indication when the minimum safe level of rock dust is reached. The CDEM-1000 sets the minimum safe level of rock dust at not less than 80 percent in the absence of methane and increases the minimum safe level of rock dust by 0.4 percent for each 0.1 percent of background methane at the sample site.
Ordering information for the CDEM-1000 Kit:
For NIOSH/CDC CDEM-1000 evaluation and application info, click here for IC 9529.
The CDEM-1000 Starter Kit ships complete with everything required to create and dry calibration samples, along with the supplies to dry and perform fractional rock dust mine sampling.
The following accessories are standard in every kit:
- CDEM-1000 Coal Dust Explosibility Meter
- Carrying Case (includes shoulder strap)
- Calibration Preparation Supplies:
- 2ea. Funnels with 20-mesh (850 μm screen) to fit 4oz. calibration vials.
- 2ea. 50(g) PPC calibration coal dust standards in 4oz. vials.
- 1ea. 4oz. vial filled with Activated Molecular Sieves.
- 1ea. 4oz. vial labeled for 100% PPC coal dust standard.
- 1ea. 4oz. vial labeled for 100% RD rock dust standard.
- 1ea. 4oz. vial labeled for 80% Green/Red Boundary sample standard.
- Sample Preparation Supplies:
- 6ea. 2oz. Plastic Vials with Activated Molecular Sieves.
- 2ea. Funnels with 20-mesh (850 μm screen) to fit 2oz. calibration vials.
- 5ea. Sample Cups with minimum fill line indicated.
- 1ea. Spatula
- 1ea. Lens Brush
The part number for the CDEM-1000 Deluxe Kit is 810-1101-01.
Ordering information for the CDEM-1000 Kit:
CDEM-1000 Deluxe Kit......................810-1101-01
View the circular:
The instructional videos below were developed by NIOSH, CDC, and OMSHR using the Sensidyne CDEM-1000 and demonstrate how to measure coal dust explosibility during rock dusting.
5.4 x 2.4 x 1.2 inches
(13.7 x 6.2 x 3.2 cm)
70 – 100% rock dust by weight
Every 200 tests or with a change in rock dust supply
Reflectance Standard Check
Every 1000 tests
9 volt alkaline battery
Low battery indicator and auto power down
Range 10 to 40 degrees C
(50 to 104 degrees F)
+/- 2% rock dust for dust mixtures above 70% rock dust when proper sample preparation and unit calibration is performed
Extended Red Display
Displays a % rock dust range for ***RED*** indications at or above 70% rock dust