How to Make the Right Decision When Making Your Gas Monitoring Purchase

Do you know the total cost of your gas monitoring program? From initial purchase, testing, maintenance, repair, training and finally replacement, it’s probably much more than you think! Most people immediately think of just the purchase price, but that’s not the whole picture when it comes to keeping your monitor in working order over the life of the device. Purchase price typically accounts for only one third to half of the total cost of ownership for a gas monitor. If you don’t perform the needed maintenance, you could be caught on scene with a malfunctioning monitor and if it hasn’t been tested you may not even know it. It may not alarm when it should. In this article we’ll review a lot of costs associated with gas monitoring, along with some options to think about that might keep you safe at a lower cost.


When deciding what monitor to purchase, you need to determine your organization’s mission when it comes to gas monitoring.

  • What gases do you need to monitor for? This is the most basic question but most important question.
  • Do you just need to monitor for firefighter safety during or after a fire?
  • Do you respond to CO alarm calls a majority of the time?
  • What target hazards exist in your coverage area that you might need special monitoring for?
  • Are you trained for confined spaces or industrial rescues?
  • What capabilities do your mutual aid departments or other available resources have? 

By determining your scope before you purchase it will help you decide what you will need for your gas monitoring program. I call it a program because you typically aren’t just buying one piece of equipment. You also need to purchase all the supporting equipment to service and maintain the equipment.

If you are mainly concerned about firefighter safety during overhaul, you may be able to use a single gas CO or HCN monitor to determine when it’s safe to remove SCBA. This is the most basic level of monitoring and should be attainable by every fire department that operates interior. For any type of confined space or industrial rescue you must at least monitor for Carbon Monoxide (CO), Hydrogen Sulfide (H2S), and Oxygen (O2). Oftentimes, this may be a rare occurrence and may be within the scope of mutual aid or regional resources. If that’s the case, make sure you plan ahead so you know who to call when you need the resource!

The first cost that you need to account for is purchase price. Remember, the price is typically going to be an indicator of a few things. First, the quality of the device. As a rule, the more expensive the purchase price the more capability the meter will have or the longer the warranty will be. This doesn’t always hold true but is a good generalization.  A five-gas meter will typically be more expensive than one that can monitor fewer gases. On the other side of the spectrum, there are some no-name monitors being imported from overseas that may be inexpensive, and they may be great monitors, but the tradeoff will be what service you will get when the meter breaks. Typically, the lower price would result in poor service and a non-existent warranty. You may get a grant to purchase a more expensive name brand monitor that has more functionality, but you need to ask yourself if those functions will be within your organization’s capability. Remember, if you buy the fancy meter with lots of features you’re going to have to make sure everyone is trained to use those features (Hint: Hidden cost!). Don’t fall into the trap of thinking that purchase price is the only cost! As you will see, there are lots of other factors that will impact your overall cost of ownership.

Testing and calibration costs can vary depending on the complexity of the equipment you purchase.  There are usually two separate tasks. Calibration is done less often, usually once a month. Bump testing is performed more often to verify that the sensor is functioning correctly. Make sure to read the manual and follow the requirements for routine testing. For conventional electro-chemical sensors this usually means testing daily, or before each potential exposure. This can be accomplished with a bottle of test gas, regulator and some tubing. For some gases, these supplies may be cost prohibitive. For example, Hydrogen Cyanide gas is very corrosive. The regulator, tubing and test gas are much more expensive, and the shelf life of the gas is short. Prior to purchasing, you should find out the cost of the expendable supplies, as well as the cost of any testing fixtures needed. Most monitors will come with a test cap that attaches to the monitor just for this purpose. Often, manufacturers will sell automated testing stations at an additional cost that make the testing easier or expand the capabilities of the monitor through additional features, such as data logging or custom alarm programming. This additional cost needs to be researched prior to purchase to determine if additional testing capability is needed. It might be very valuable if it means the monitors will be tested on the schedule the manufacturer specifies. Beware of non-compliance with the testing regimen as that could open your organization up to liability, especially if someone gets hurt!

One hidden cost to testing is the time it takes to do the tests. If you purchase several single gas monitors and the manual requires a bump test every day, do you have the resources to accomplish the test every day? Calibration is typically done on a regular schedule, or when a few other conditions are met, such as if a daily bump test fails, when there are environmental changes, if the monitor was dropped or if it was exposed to a high concentration exposure. Another hidden cost in testing is the cost of replacement sensors when a calibration test fails. You want to find out prior to purchase if this is covered by warranty or if you’ll need to replace sensors at a significant cost over the life of your monitor. If you do need a new sensor — or some other part — where can you get your monitor repaired and how long will it take?  Your monitor won’t do you any good if it’s out of service!

Training can be a big impediment to establishing a gas monitoring program. Some monitors will be as simple as leaving them on and knowing what to do when they beep but other monitors will require knowledge of chemistry in order to interpret dangerous situations. Anyone who will be using the monitor must be trained to operate it, read alarms and troubleshoot while using it. Again, the more complex the equipment the more training will be required. This can be a daunting task just to get everyone in the same room and familiar with the same information. You should ask about any training programs available from the manufacturer as they may have something ready-made.

The final cost that needs to be considered is the replacement cost. How long will the monitor you purchase function before it needs to be replaced? How long is the warranty and what does it cover? Emerging technologies are becoming available that can lower your total costs through long warranties or longer testing cycles. Beware of some manufacturers of “sealed” monitors that may not last as long as you think. They may give a two- or three-year expected life, but the time is specified on a certain amount of alarming over the entire lifespan. What if your crew places the monitor on the ground next to a vehicle exhaust? That could use up a good portion of the lifespan in a very short amount of time, resulting in an added expense of replacing that monitor prematurely. The replacement cost may be much higher than purchasing a more expensive monitor up front that will last much longer or have a better warranty.

How can you reduce your total ownership cost over the life of your gas monitor? You must do your homework before the purchase. Make sure you don’t overbuy and over-commit your resources. Don’t buy a monitor you can’t afford to maintain, and don’t buy a monitor that is beyond your training. Make sure you know and budget for all the extra costs so you can factor the total expense from the beginning.  The least expensive option to purchase many times is not the least expensive option overall. 

Peter Mills has been a firefighter/EMT for over 20 years, currently holding the rank of lieutenant. He is the National Sales Development Coordinator for Airspace Monitoring Systems of Mequon, WI. Airspace develops gas monitoring equipment for emergency responders.

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