FUNDAMENTALS

MINE SERVICES

 

Monitoring and Remote Control

  
 

Monitoring and Remote Control

General

These two functions are included together as the need for and the ability to safely use remote control frequently depends on monitoring and both systems use the same method of transmission.

Monitoring can be split into 4 general areas:

Each of these include:

  • Personal or manual monitoring using hand held instruments or installed gauges, etc

  • Automatic or remote monitoring.

Note that in addition to the above everybody monitors a multitude of items continually, often unconsciously, using their senses. While this is seldom acknowledged formally its importance cannot be over stressed as this can be the first indication of problems, often before instrumentation can detect potential changes. It is also the main type of monitoring required by the majority of inspection regimes which only specify instrument readings in a few areas.

Manual monitoring is usually carried out as part of these inspection regimes on a reasonably regular though intermittent basis. In almost all cases automatic monitoring should be considered as a desirable extension of the information gathering process and very seldom as a replacement for personal inspection. Both manual and automatic monitoring have advantages and limitations.

In order to ensure safety and avoid needless lost time, it is important that personnel using any type of monitoring fully understand the system, how it works, its accuracy, its limitations and how it will react to given situations. It is frequently the case that monitors (hand held and automatic) give misleading information, particularly with regard to accuracy, and trends may be more informative than absolute values. As a general principle immediate action should be taken to ensure the safety of personnel and the mine assuming monitoring readings are correct and to then check the accuracy of the monitor by other means, if safely possible.

All systems require a high standard of maintenance to be effective; note that a system which gives many false alarms becomes a hazard in itself as alarms will be ignored or treated with little urgency and it could be a genuine one.

Results of manual monitoring are usually recorded in written reports (often statutory reports). Automatic monitoring results are typically transmitted to a remote location, usually to surface to a control room or similar, and increasingly to a data processing system which will record trends, initiate audible and/or visual alarms at pre-set levels and possibly calculate useful values (explosibility of gas mixtures, Graham's ratio, CO make, oxygen deficiency ratios, etc).

Some monitors are used to raise alarms at a local level and possibly trip power to machines at that location, whilst other alarms can initiate mine-wide responses.

Remote control of some items of machinery can be very useful, especially such items as pumps which may well be in locations remote from personnel. Remote control will require machinery and possibly the environment to be monitored to ensure the machine can be started safely and with limitations on the ability to restart depending on the reason it had stopped. Adequate guarding and pre-start warnings would also be a requirement in some cases.