Businesses and professionals need to choose a gas monitor based on where they are working. Gas monitors should detect gases that are likely to be present in the space. Fixed monitors are used for ongoing monitoring, while portable gas detectors are used by workers in the field.
Protecting your workforce from hazardous gases starts with choosing the right gas detection devices based on the task at hand. Several important factors should be considered when selecting this equipment for your team: the nature of the worksite, the target gases present in the atmosphere, and how long your workers plan to occupy the space.
Choosing the right type of equipment isn’t always clear. PK Safety is here to help you understand the options available on our website, so your team can do the job at hand without putting their health and safety at risk. Use our comprehensive gas detection selector guide to find the right device for your chosen application.
Types of Gas Detection
Not all gas detectors work the same way. They generally fall into one of three categories: portable gas detectors, fixed gas detectors, and gas detection tubes (or colorimetric detection devices).
Portable Gas Detectors
Portable gas detection devices are made for workers who need to monitor air quality on the go. They are used by first responders, utility repair crews, and those working on location or in the field. Portable gas detection devices are worn by the person in their breathing zone, the area near the person’s nose and mouth, to ensure the device monitors the same air the person breathes in. Additionally, these devices are lightweight, portable, and easy to carry around. Most options come with a clip that attaches to the worker’s collar, bag, or lapel, ensuring it remains firmly in place regardless of the task performed.
All portable systems run on batteries that typically last several hours to days at a time. Some, like the popular BW Clip 2 Year H2S Single Gas Detector, may run continuously for its entire lifespan (2 years). No need for calibration, sensor replacement, battery replacement or battery charging. Verify that the estimated battery life accommodates the worker during their entire shift. After use, the person can store the detector in a gas detector docking station which will automatically charge the battery, perform a bump test, and recalibrate the device as needed. The station also keeps a digital log of the results for automated reporting.
Some options are also waterproof to protect against spills and leaks. Choose a more durable model that is easy to clean when working in unsanitary areas or during natural disasters.
Portable gas detectors can detect many types of hazardous gases, including the four main target gases. You can choose between a single and multi-gas monitor. Single-gas monitors only detect one hazardous gas at a time, while multi-gas monitors can typically detect four or more hazardous gases at once. An electrochemical sensor is used to measure the amount of toxic gas in the air as a percentage of the total air supply in relation to the permissible exposure limit (PEL) and the lower explosive levels (LEL), or the point at which combustible gases are likely to explode.
These gas monitors are typically used in confined spaces with limited ventilation, such as manholes, utility tunnels, mines, and certain businesses and facilities. Hazardous gases are commonly found in these environments, gradually settling in the air. The most common gases include hydrogen sulfide (H2S), methane (CH4), carbon monoxide (CO). Exposure to these gases can be extremely dangerous as they are highly flammable and can significantly increase the risk of flash fire.
When the hazardous gas (or gases) surpasses the PEL, LEL, or customized threshold, the device promptly alerts the user through an audible, vibrating, visual alarm. The alert can reach the user even in loud or low-visibility environments.
Fixed Gas Detectors
Unlike portable detectors, fixed gas detection systems stay in one location. They are installed or mounted in fixed positions in areas where hazardous gases are likely to gather and are not meant to be moved once they are put into place. They are used in recurring work environments where workers may spend their time, including certain confined spaces, warehouses, and any common area with limited ventilation.
You can use fixed gas detectors to monitor your workspace continuously or for long periods without interacting with the device. Fixed monitors require regular access to electricity. It’s usually best to have a trained professional install the monitor onsite.
Like any gas monitor, it uses an electrochemical sensor to measure the amount of gas or gases in the air based on the PEL, LEL, and other customized thresholds. You can use a single or multi-gas fixed gas monitor based on the target gas. In many cases, fixed gas monitors automatically record their findings, which can be accessed on the complimentary app or software system.
When the monitor detects a high level of hazardous gases based on the threshold, it emits an audible, flashing alarm to get the attention of everyone within a set range. Install the device where workers can easily see or hear the alarm when it goes off. If you are trying to cover a large space or occupy a loud space with poor visibility, use as many fixed gas detectors as needed to keep everyone within range.
Gas Detection Tubes
Gas detection tubes are small glass tubes that use colorimetric chemicals to detect the presence of hazardous gases. They are inexpensive and easy to use on location when first surveying your workspace, also known as spot testing. The chemicals in the glass tube change color when hazardous gases are present in the atmosphere. The results are usually available in seconds, so you can quickly determine whether respirators or additional gas detection equipment is required.
All gas detection tubes are single-gas monitors and can only detect one gas at a time. They are available for a wide range of target gases, including the four main gases. The tubes are also wireless and do not run on electricity. They don’t need to be charged, but each tube has a set expiration date. After the expiration date, the results are no longer reliable.
Tips to Keep in Mind: Gas Detectors vs. Gas Monitors
As you begin the equipment selection process, you must understand the difference between the terms “gas detector” and “gas monitor.” They are often used interchangeably but don’t always mean the same thing.
A gas detector is a portable device worn on the user’s person. They are typically used by crews working on location or responding to emergencies.
A gas monitor is usually a fixed device that works with a larger gas detection system. They often communicate wirelessly with one another as part of a network, so all the alarms go off at once when hazardous gases are present in the space. For example, each room or hallway may have its own gas monitor that reports to the central monitoring station.
Care and Maintenance
Both fixed and portable gas detectors require regular care and maintenance. It is crucial to bump test all monitors before the start of every shift. If the test results are off, the sensor needs to be recalibrated. Bump testing checks if the device is working properly, calibration checks on the accuracy. The sensors on the device lose their effectiveness and reliability as they age. Follow the replacement recommendation of the manufacturer (typically 3 to 5 years), to extend the life of your device.
Many of the gas detectors on our website have a three or four-year warranty that covers the cost of repairs. Keep the device clean and in good condition by storing it in a dry, room-temperature location.
Not all gas detectors are made alike. Each device has pros and cons. Consider the nature of the job and how your workers interact with the space to find the best device for your team. Help is just a call or click away. Contact the professionals at PK Safety to speak to a professional when choosing a gas detector or monitor for your business.