Gas monitors for refuge chambers allow occupants to inspect gas levels inside and outside the chamber closely. Also, when needed, take corrective actions to maintain a safe and inhabitable environment during an emergency.
Due to certain conditions, some gases can occur in a chamber. During entrapment, occupants consume oxygen and exhale carbon dioxide and carbon monoxide as part of their normal respiration. CO and other gases can also enter the chamber during occupant entry and if the compressed air intake is compromised. As a result, internal gases need to be monitored by a digital gas monitoring system or manual gas sampling.
Digital Gas Monitors for a Mine Refuge Chamber
Portable or fixed Digital Gas Monitors (DGMs) automatically detect the presence of gases within an area. The monitors contain specific sensors used to identify hazardous levels of combustible, flammable and toxic gases as we as oxygen depletion within the confines of a refuge chamber.
DGM’s must be calibrated, with portable devices requiring more frequent scheduling. Calibration involves measuring the readable output of the sensor against a known standard to determine accuracy.
Bump tests allow for more frequent examination. These tests expose the gas sensor to a known concentration of the gas, ensuring any audible or visual alerts are activated.
Manual Gas Monitors for a Mine Refuge Chamber
As a fail-safe, manual gas sampling tube should be in every refuge chamber, along with tracking equipment. Manual Gas Sampling uses single-use, pre-filled chemical tubes that react to air being drawn through the hand-held pump device to test the levels of O2, CO and CO2. A calibrated scale printed on the tubes indicates gas concentrations.
Occupants within a chamber are required to take a sample of air, every hour, and measure gas levels using the instruction on the sampling pump.
External Gas Monitors for a Refuge Chamber
In some circumstances, it may be beneficial to place gas monitors of the exterior of the chamber to notify occupants of external hazards. Customised manifolds enable the measurement of external gases while maintaining a seal against the outside environment. The manifold is placed over a pair of display board modules, sealing directly over the intended sensors. A switch is mounted on the front face to turn on a sampling pump to pull external air over the sensors; the pump then exhausts to the exterior.
Aura-FX Sensor Technology
MineARC Systems utilise a fixed gas detector, specially designed for use in refuge chambers and safe havens, called the Aura-FX Digital Gas Monitoring System (Aura-FX).
Aura-FX provides a more advanced solution to internal and external gas monitors for a refuge chamber. Capable of individually monitor anywhere up to 11 gases, plus ambient temperature, via a series of user-friendly, digital screens. Available in fixed, compact, and external designs Aura-FX can be retrofitted onto existing chambers and is included in all new models.
Audible voice alarms will prompt occupants to replace scrubbing chemicals or adjust oxygen supply levels into the refuge chamber as required.
When utilised as a part of the GuardIAN Intelligence Network, Aura-FX provides real-time gas monitoring data and analysis to the surface. There are several MineARC products that feature Aura-FX sensor technology to detect, alert, and transmit information on particular gas levels within a mine. Currently, the range includes:
- Aura-FX Digital Gas Monitoring System: A fixed or compact digital gas monitor observes gas levels within a MineARC Refuge Chamber. It is also capable of sending information to the surface via the GuardIAN Refuge Chamber Monitoring dashboard.
- Aura-FX External Gas Monitor: Designed to measure gas levels outside of the refuge chamber, the external Aura-FX sensors will detect gases while maintaining a seal against the outside environment.
- GuardIAN Nodes: Monitor gas levels in surrounding areas, through an expandable network, allowing increased coverage and accuracy of data transmitted between MineARC Refuge Chambers, underground personnel, and above-ground control.
- Aura-PT: A handheld gas detector has been designed to provide underground personnel with the ability to monitor up to six gases within their immediate surroundings. Aura-PT automatically communicates dangerous gas levels back to the GuardIAN Server via the GuardIAN Nodes.