11
displacement and stress-measuring instrumentation.
Specific products mentioned in this paper are in use by
NIOSH, but this is not intended to provide an all-inclusive
list of instrumentation and data acquisition systems on the
market. There are multiple variations of these products,
particularly in the area of displacement measurement, avail-
able to the consumer. These include various extensometers
often referred to as telltales, miner’s helpers, or guardian
angels. Additionally, there are many other devices capable
of measuring strain, pressure, and deformation of boreholes
at consumers’ disposal.
Other limitations to implementing a ground-control
monitoring program include accessibility to MSHA-
approved/permissible dataloggers, availability of certain
instrumentation, and NIOSH’s interpretation and adap-
tation of installation procedures. The most challenging
constraint to overcome pertains to MSHA-approved data
monitoring systems.
Currently, there are no currently available permis-
sible monitoring systems like the Campbell and MIDAS
systems discussed previously. Nonpermissible monitoring
systems can currently be purchased for use in nongassy
mines. Because of this, there is gap in underground coal
instrumentation needs related to a commercially available
permissible datalogger that meets MSHA requirements. To
bridge this gap, periodic readings can be taken with the
use of handheld readout devices provided by instrument
manufacturers.
The availability of instrumentation poses a challenge,
particularly for the in-house production of the multipoint
roof extensometer. Similarly, the standing support load cell
has availability constraints, as the steel bladders are cur-
rently contracted for manufacturing in accordance with
NIOSH specifications. The components of both items are
available commercially for operators willing to do some
light fabrication or have custom orders made. Additionally,
multiple alternatives for roof extensometers are available on
the market but will require modification to the installation
procedures based on the manufacturer’s recommendations.
Some of the installation procedures provided in this
guideline have been modestly adjusted from manufacturer
specifications to accommodate the limitations of the mine
environment and equipment capabilities. These guidelines
represent NIOSH’s best practices, aiming to minimize
impact to mine production yet maintain data reliability
and quality.
CONCLUSION
In conclusion, this paper presented the available ground-
control instrumentation and data acquisition used by
NIOSH researchers. Mine operators and engineers who
intend to start or enhance a ground-control monitoring
program can use this information as a reference guide to
better understand what instrumentation is available, what
it is capable of measuring, and how NIOSH researchers
utilize this data to further the NIOSH mission of reduc-
ing groundfall-related injuries and fatalities. Through high-
lighting the application and installation procedures of each
instrument, data monitoring, and possible limitations,
this guideline equips mine operators with the necessary
resources to conduct their own comprehensive studies.
DISCLAIMER
The findings and conclusions in this report are those of
the authors and do not necessarily represent the official
position of the National Institute for Occupational Safety
and Health, Centers for Disease Control and Prevention.
Mention of any company or product does not constitute
endorsement by NIOSH.
REFERENCES
Campbell Scientific, Inc. (1995). 21XQM Micrologger
User Manual. Retrieved from s.campbellsci.com
/documents/au/manuals/21xmicrologger.pdf.
Figure 18. Campbell Scientific’s 21XQM model is currently
configured for monitoring Hollow Inclusion (HI) Cells
displacement and stress-measuring instrumentation.
Specific products mentioned in this paper are in use by
NIOSH, but this is not intended to provide an all-inclusive
list of instrumentation and data acquisition systems on the
market. There are multiple variations of these products,
particularly in the area of displacement measurement, avail-
able to the consumer. These include various extensometers
often referred to as telltales, miner’s helpers, or guardian
angels. Additionally, there are many other devices capable
of measuring strain, pressure, and deformation of boreholes
at consumers’ disposal.
Other limitations to implementing a ground-control
monitoring program include accessibility to MSHA-
approved/permissible dataloggers, availability of certain
instrumentation, and NIOSH’s interpretation and adap-
tation of installation procedures. The most challenging
constraint to overcome pertains to MSHA-approved data
monitoring systems.
Currently, there are no currently available permis-
sible monitoring systems like the Campbell and MIDAS
systems discussed previously. Nonpermissible monitoring
systems can currently be purchased for use in nongassy
mines. Because of this, there is gap in underground coal
instrumentation needs related to a commercially available
permissible datalogger that meets MSHA requirements. To
bridge this gap, periodic readings can be taken with the
use of handheld readout devices provided by instrument
manufacturers.
The availability of instrumentation poses a challenge,
particularly for the in-house production of the multipoint
roof extensometer. Similarly, the standing support load cell
has availability constraints, as the steel bladders are cur-
rently contracted for manufacturing in accordance with
NIOSH specifications. The components of both items are
available commercially for operators willing to do some
light fabrication or have custom orders made. Additionally,
multiple alternatives for roof extensometers are available on
the market but will require modification to the installation
procedures based on the manufacturer’s recommendations.
Some of the installation procedures provided in this
guideline have been modestly adjusted from manufacturer
specifications to accommodate the limitations of the mine
environment and equipment capabilities. These guidelines
represent NIOSH’s best practices, aiming to minimize
impact to mine production yet maintain data reliability
and quality.
CONCLUSION
In conclusion, this paper presented the available ground-
control instrumentation and data acquisition used by
NIOSH researchers. Mine operators and engineers who
intend to start or enhance a ground-control monitoring
program can use this information as a reference guide to
better understand what instrumentation is available, what
it is capable of measuring, and how NIOSH researchers
utilize this data to further the NIOSH mission of reduc-
ing groundfall-related injuries and fatalities. Through high-
lighting the application and installation procedures of each
instrument, data monitoring, and possible limitations,
this guideline equips mine operators with the necessary
resources to conduct their own comprehensive studies.
DISCLAIMER
The findings and conclusions in this report are those of
the authors and do not necessarily represent the official
position of the National Institute for Occupational Safety
and Health, Centers for Disease Control and Prevention.
Mention of any company or product does not constitute
endorsement by NIOSH.
REFERENCES
Campbell Scientific, Inc. (1995). 21XQM Micrologger
User Manual. Retrieved from s.campbellsci.com
/documents/au/manuals/21xmicrologger.pdf.
Figure 18. Campbell Scientific’s 21XQM model is currently
configured for monitoring Hollow Inclusion (HI) Cells