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Confined Space Gas Monitors
Confined Space Gas Monitors
Confined spaces are potentially dangerous places that should be avoided at all costs. Whether we like it or not, sometimes confined space entry is essential and cannot be avoided. If this is the case then there are several steps that should be taken to ensure the safety of personnel entering confined spaces and of those in the vicinity. In this paper we deal with the confined space gas monitor selection for pre-entry checks and for use during the time spent in the confined space .
Choosing a confined space gas detector for pre-entry checks and continuous monitoring whilst in the space may sound easy, but there does need to be some thought put into the decision. For example are we going to need a pump to draw a sample prior to entry, what are the gases I need to detect, how many people will I have in the confined space and what are the potential gas hazards once the space has been entered.
All these questions can be answered with a confined space risk assessment that should be done be qualified personnel. The most common form of gas monitor is the 4- gas version that is fitted with an explosive sensor (LEL) usually calibrated to Methane (CH4), Oxygen (O2), Carbon Monoxide (CO) and Hydrogen Sulphide (H2S). However this can change subject to the findings of your risk assessment. Some people prefer the use of pumps to draw a sample and others will go for the old-fashioned method of dropping the gas monitor into the space attached to a line. Both methods are acceptable and work. The recommendation would be to ensure that there are latching alarms set on the unit as with the MSA Solaris, to ensure notification is given to the user and manual reset of the alarm is mandatory. This will guarantee the user knows that an alarm has been triggered and consequently is aware of the dangers.
Once pre-entry checks are complete and the Team Leader is happy that all precautions are in place, entry into the confined space shall be undertaken by trained personnel. These persons should have a gas monitor each so as to guarantee protection at all times. It is therefore important that each person wears the gas monitor around the breathing zone. The gas monitor therefore, should be small, light and easy to wear. The BW Gas Alert Micro Clip is ideal for this as it fits the criteria. When worn around the breathing zone, it is very important that the user is aware of any alarms that the gas detector emits, so as many methods of warning as possible should be employed. Both the MSA Solaris and the BW Gas Alert Micro Clip have 3 methods. There are audible alarms that trigger a sounder, a bank of flashing LED’s and an internal vibrating alarm. This ensures that any other Personal Protective Equipment does, and can’t, mask all the alarms.
The cost of the unit is a very important factor. Just because a unit is cheap to buy doesn’t mean ongoing costs will be low. Checks should be made into calibration cost, sensor warranty periods and whether there is a local calibration outlet that is able to perform a quick turnaround.
Overall the requirements for the “confined space monitor” should be considered prior to purchase and not just buying the cheapest. It should be a 4-gas (at least), easy to use, easy to maintain, well guaranteed and light in weight.
This page was created on: 10/09/2007
Last modified: 10/27/2007
