Gas Meters 101
Gas Detection Equipment can be broken down into two categories:
- Fixed Detectors - hard wired instruments typically installed in areas where flammable or toxic vapors are likely to be. When gases are detected audible and visible alarms are activated.
- Portable Gas Monitors - small monitors designed to be mobile. Often they are the size of a paper, radio or lunch box. They include;
- Single Gas Detectors - designed to detect one particular gas. They can be a passive detector like a badge, a spot, method of detection as with sample draw tubes, or a real time gas monitor that continually updates readings.
- Multi Gas Meters - monitors several gases simultaneously and are usually configured for Oxygen, Combustible Gases, and two toxic gases. These are primarily used as confined space monitors. There are also instruments capable of 5 different sensors in varying configurations.
Note: Some sensor technologies allow monitoring of an entire group of gases such as flammable or volatile organic compounds,
Sampling Methods:
- Diffusion - these instruments simply monitor the atmosphere in your personal space. These are often referred to as personal monitor and can be as small as a pager or credit card.
- Sample Draw - these pump modules draw the gas to the sensors for measurement. Gas monitors with a sample draw pump are preferred when pulling samples from confined spaces, continuously monitoring, or measuring for small trace amounts like in soil head space measurements.
Note: Since a pumped meter can be used in a variety of situations including a personal monitor, it's typically a good idea to look at gas monitors equipped with a pump. Adding tubing to a pumped gas monitor is helpful in drawing the sample from deep confined space. See our ATD note for more information.
Run Time
When you buy a gas meter, you're purchasing the ability to safely do your job. The gas monitor should be able to work for at least as long as you. With today's technology, rechargeable batteries run longer, recharge quicker and don't need replacing as often. Consider an alkaline batter pack as a back-up. Avoid NiCad packs which are prone to developing a "memory" and often require meticulous discharge cycles . The latest technology available is Lithium Ion batteries like the one in cell phones.
Ease-of-Use
Ease-of-use is the most important aspect of them all. People simply won't use a piece of equipment that they don't know how to operate. Be sure that the operation of the gas meter is easy to figure out. Look for features such as training videos, live training sessions with the vendor and quick reference cards. If the operation of the meter can be boiled down to a laminated card, most likely it will be easy to use.
Datalogging
Datalogging is a feature that will allow you to store the data captured during your gas monitoring sessions. This can be very helpful in proving that your doing your job safely and correctly.
Back to Gas Detection Instruments