Portable Gas Detectors: Types, Features & Alarms

According to Honeywell, portable gas detectors make up nearly half of the total of modern, electronic gas detectors in use today. How do you know you’re using the right one for your environment, and have the right features to keep you protected against all potential gas hazards in your workplace?

Recent Innovations

The beauty of modern society is that technology is constantly evolving; this includes advances to portable gas detection. Some of the advances that have been made to portable gas detectors include:

• More robust and lightweight materials for construction.
• Higher power microprocessors for enabling enhanced data logging and self-checking.
• Use of modular designs that allow simplified routine servicing and maintenance.
• Improvements to batteries, extending the operating time between charges and a smaller battery pack.

Why Portable Gas Detectors are Important PPE

Although fixed gas detection is vital in most environments where gas hazards are present, there are situations where portable gas detectors really come into their own.

Portable gas detectors are the only way a worker can monitor their breathing zone continuously, regardless of whether they’re stationary or moving around an area. This removes the possibility that personnel could move into an area where they cannot identify any potential gas hazards.

If an area within the working environment is not entered very often, it is likely that installing fixed gas detectors is not cost-effective. The area may also be small or hard to reach, making fixed detector placement impossible. In these cases, portable gas detection is essential.

Types of Portable Gas Detection

All portable gas detectors will fall into one of two groups, depending on the gas they detect:

• Single gas: Detectors that monitor only one type of gas.
• Multi-gas: Devices that can detect multiple gases. These usually range between 4 and 6 different gases.

Portable gas detectors also fall into two separate categories when looking at maintenance and longevity:

• Serviceable: Long-term detecting device, requiring ongoing maintenance that can be carried out by the user or a third party service provider.
• Disposable: Short-term detecting device that operates for around 2-3 years and does not require any maintenance during its life. These types of detectors are usually operational from when they are first activated until they expire.

Operation Modes of Portable Gas Detectors

Portable gas detectors usually have two operation modes for monitoring the atmosphere:

• Diffusion: Operation mode that allows air to diffuse into the sensor. This is used for breathing zone monitoring and will be the primary operation mode for most portable devices.
• Sampling: During sampling, air is drawn into the sensor via a motorised pump or sample kit (including a hand aspirator). Sampling the atmosphere is essential in an area that contains potential hazards, as it allows the user to sample the air before entering the area and putting themselves at risk.

Features of a Portable Gas Detector

Portable gas detectors can vary widely due to the huge scope of functions and applications that they are required for.

• Visual Display: Many devices feature a real-time display to show gas levels and other operational icons. This gives the operator extra peace of mind as they can see a real-time value of gas levels before an alarm sounds, and can also see that the detector is operating correctly under the right mode.
• Ingress Protection: This indicates the detector’s suitability to the environment where it will be used, factoring in impact and water resistance as well as dust and dirt. Using a detector with the right ingress protection for your application will ensure the longevity of the device.
• Button Operation: Some devices have one single, large button whereas others will feature multiple buttons. Using buttons means that users can operate the device more easily and without having to take off other PPE such as gloves.
• Integrated Datalogging: Any event, such as a gas alarm, will be stored in the device to be downloaded later and reported on by a manager. This automated process simplifies event reporting, an essential protocol for many insurers.
• Battery Performance: A high performance, quick-charge battery is essential for covering long shifts without needing to be recharged.
• Sensor Integration Types: Some devices allow individual sensors to be added or removed, while others use an integrated sensor cartridge. Individual sensors mean that the device is flexible to being updated while keeping other sensors intact; whereas integrated sensor cartridges provide a quick and simple means of replacement, reducing time and cost of maintenance.
• Motorised Sampling Pump: Devices that can switch between diffusion and sampling mode can save time from using a manual sampling kit, which would need to be fitted to the device. Air flow is also regulated more effectively when a motorised sampling pump is used.
• Alarms: Most devices will feature visible, audible and vibrational alarms, to ensure they grab the attention of the user, even in high-noise locations.
• Visual Compliance Indicators: Some devices feature visual indication LEDs that are automatically deactivated when the device is overdue for essential calibration or bump testing. This makes non-compliant devices easier to spot, ensuring that all detectors are working as they should be.

Alarms & Status Indication on Portable Detectors

The main purpose of a portable detector is to alert the user to potential gas hazards, making the alarm one of, if not the most important feature of the device.

Alarms can be configured for various conditions ensuring that the alarm always indicates impending danger before it becomes a dangerous situation:

• Short term exposure limit (STEL): 15-minute duration.
• Long-term exposure limit (LTEL): 8-hour duration.
• Low level alarm: Defining the low alarm set point.
• High level alarm: Defining the high alarm set point.

Portable detectors really come into their own when a user is working in an area with potential toxic gas hazards, where they cannot be exposed for long periods of time or high concentrations without serious danger. STEL and LTEL alarm types provide this protection and alert the operator when maximum exposure levels are reached.

Portable gas detectors are essential in areas where fixed gas detection falls short, ensuring that your workforce is comprehensively protected from any and all danger that gas presents. For more help and guidance on creating a gas detection system that is right for your environment, get in touch with us.