Did you know that workers are needlessly injured every year as a result of leaking toxic or combustible substances? Such incidents are known to involve a wide range of hazardous gases (including ammonia, carbon monoxide, chlorine, hydrogen sulfide, hydrocarbon vapors and so on). The sad reality is that most of these accidents are avoidable if only the workplace is adequately monitored. This leads to the question of whether fixed or portable gas detection is the most appropriate for your needs – here is a comparison.
The Difference – Fixed
A fixed detection system typically consists of one or more electrochemical cell (EC), metal oxide semiconductor (MOS), catalytic-bead (CB) or infrared (IR) sensors placed in key locations around the workplace. When a combustible or toxic gas is present in these areas outside of acceptable limits, an alarm will sound that indicates to nearby workers that they need to evacuate. Exposure data will also be sent to a main control station.
The Difference – Portable
A portable detection system typically relies on electrochemical cells (EC) and are utilised in confined spaces or large areas where fixed systems are impractical or cost-prohibitive. Besides, entry to confined spaces is often infrequent and the danger is related more to oxygen deficiency than a hazardous substance. When the sensor detects a toxic or combustible gas or a lack of oxygen, it will alarm and warn the worker that they need to get out.
When organising a hazardous substance safety program for your workplace, there are a number of important factors to consider. No matter what type of detector your require, you will need to undertake the following:
- Walk the plant to check potential leak sources, think over the placement of any fixed detectors and identify any confined spaces that would require portable devices.
- Review the workplace’s ambient operating environment; make sure you watch out for temperature and humidity extremes, as these may affect the accuracy of readings.
- Consider the various fixed and portable gas detectors technologies currently available, as these will ensure exceptional performance and reliability for your workers.
- When choosing fixed devices, consider ease of installation, calibration and maintenance as the main points (they should certainly be considered above the price).
- When choosing portable devices, consider ease of use, training, battery life and service life as the main points (they should certainly be considered about the price).
Protecting a chemical plant against combustible vapors, for example, is often best achieved through the use of catalytic-bead technology. This involves fixed detectors being placed throughout the facility. Whilst you could provide every single worker with a portable device, how can you guarantee that they would always wear the sensor and maintain them? If they aren’t in good working order, the detectors are essentially useless.
In a confined space, on the other hand, the technology of choice is typically electrochemical sensors as a portable device. Tanks need to be cleaned, pumps will require maintenance and oxygen efficiency can occur (and is deadly in such environments). Placing fixed detectors in these locations is both impractical and costly (given that they aren’t entered very often). In these cases, it is best to equip workers with a portable unit.
Unfortunately, no single device will be able to provide the sensitivity and response time required for every toxic or combustible substance that could be present. You will need to start by indentifying the gas hazards, then move onto the available fixed or portable gas detection technologies. Finally, you will need to analyse the features of each of the devices themselves. Combined, these factors will ensure that you have made the right selection for your workplace, whatever this may be, keeping your workers safe.