The 9 Best Carbon Monoxide Meters

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This wiki has been updated 25 times since it was first published in February of 2017. Carbon monoxide is an odorless, invisible, and potentially dangerous gas, so it is important to monitor for it carefully and accurately. These CO meters are easy-to-use, relatively affordable, and can help first responders, building inspectors, and cautious homeowners alike stay safe and protect others from poisoning. Conveniently, some of them also double as digital thermometers. When users buy our independently chosen editorial recommendations, we may earn commissions to help fund the Wiki.

1. Klein Tools ET110

2. Forensics Detectors CO Alarm

3. UEI Test Instruments CO71A

Editor's Notes

February 11, 2021:

Although the Fluke Networks CO-220 is still identified on the company’s website, it’s listing elsewhere seems to have disappeared altogether, so we went ahead and removed it from our rankings for the time being. We also removed the GXG-1987 Precision Gauge and Kidde Copp, due to availability issues, but we were quick to replace the latter option with the X-Sense CO03D — an at-home carbon monoxide detector that we thought was worth including at the bottom of our list, in the spirit of covering all our bases, as wa described in the October 17, 2019, editor’s note for this page.

Our other new additions this time around were the Cheffort Handheld — which is both affordable and, as the name may have suggested, compact; and the Klein Tools ET110 — a solid option built by a well-reputed company and backed by a two-year warranty.

October 17, 2019:

Our previous ranking seemed only to be interested in meters that were designed for use in industrial settings by first responders, gas company workers, and similar professionals. That's understandable when so many of the CO detectors designed for use in the home don't have an actual meter, in that they lack a readout showing a count of CO in parts per million. Usually, these cheap detectors will simply sound an alarm if dangerous levels are detected without telling you how dangerous the air actually is.

There are some good examples of meters designed for home use, however, including one designed to be used inside your vehicle. We wanted to make sure all those bases were covered, so we included that and a model by Kidde in our latest ranking.

Among the more professional meters, we've added models from well-known names in the industry like Extech, and found the Pyle meter — which had had some availability concerns — relisted elsewhere. Ultimately, our ranking was based on usefulness and user-friendliness, with simple, navigable menus being among the most important features, at times even trumping a large or fancy display.

Special Honors

Fluke CO-220 It isn't the most affordable option on the market, but if you want a quality instrument from a company with a strong reputation for building diehard metering equipment, consider the Fluke CO-220. This model features a two-year sensor life and 500-hour battery life.

4. Sensorcon Industrial INS-CO-02

5. Reed Instruments R9400

6. Extech CO15

7. Pyle Hand Held PCMM05

8. Cheffort Handheld

9. X-Sense CO03D

Tools The Professionals Use

One of the most important things for you to realize as you evaluate the carbon monoxide meters on this list is that this particular selection is geared toward professionals.

One of the most important things for you to realize as you evaluate the carbon monoxide meters on this list is that this particular selection is geared toward professionals. These are not the carbon monoxide detectors that you would want to install in your home. That said, any one of them could be used in a home to check carbon monoxide levels as needed, but they're not intended to provide the same kind of around-the-clock security against a slow build-up of carbon monoxide that you'd want in your house.

Professionals will use meters like the ones on our list to determine whether the levels of carbon monoxide in a given space are safe. In extraordinarily small concentrations, the gas is relatively harmless. It's when it exceeds a specific level that it becomes particularly toxic to human beings. These meters are excellent for determining whether the carbon monoxide levels in a given space have reached that threshold. Many are also equipped with memory functions that can identify elevating levels of carbon monoxide, which can tip professionals off to the need for serious intervention.

These carbon monoxide meters are also very useful for professionals working in spaces where a carbon monoxide leak has already been identified. For example, if you have a significant leak in your home, a professional is going to have to come in and ascertain its source as well as whatever steps are necessary to mitigate the problem. In order to safely do that, he or she needs to constantly monitor the level of carbon monoxide in the space to determine whether it's immediately safe for them to work in, or whether they will need additional equipment to protect themselves from the gas.

What Happens When You’re Exposed To Carbon Monoxide?

We all know that there are certain gases that can cause significant harm to the human body with even minor exposure. Carbon monoxide is right there at the top of the list, but why is it so specifically dangerous, and what happens to your body when you're exposed to it?

That means for every molecule of carbon monoxide attached to a red blood cell, that's one less space for oxygen to occupy.

Essentially, when you inhale carbon monoxide it binds to your red blood cells the same way that oxygen would. That means for every molecule of carbon monoxide attached to a red blood cell, that's one less space for oxygen to occupy. If enough carbon monoxide enters your system, it will supplant too much of the oxygen you need to survive, causing deficiencies in the heart, the brain, and other vital organs of the body.

At first, your symptoms may not tip you off to the presence of carbon monoxide. You may feel drowsy or lightheaded, and you may even experience some tightness in the chest or difficulty breathing. Chronic or high-level exposure can lead to more severe symptoms such as confusion, vomiting, and loss of consciousness.

Fortunately, carbon monoxide levels in the home rarely exceed safe levels. Certain culprits, such as furnaces on the fritz, can potentially cause hazardous leaks in a home, but it's far more likely for someone to come into contact with large levels of carbon monoxide in their profession. Anyone who works around vehicles, especially in an enclosed area, is particularly at risk.

If your exposure is great enough to constitute carbon monoxide poisoning, you may be at serious risk for permanent damage to the heart or brain, as well as serious risk for death. If you suspect that you or someone around you has been exposed to dangerous levels of carbon monoxide, immediately get them into fresh air and attempt to ascertain the specifics and severity of their symptoms. To be safe, call 9-1-1 so that a professional emergency service provider can evaluate their condition, and if the individual stops breathing, immediately begin CPR.

What To Look For In A Carbon Monoxide Meter

Detecting the presence of carbon monoxide and alerting you to it are the basic functions of the meters on our list. Each of the units on our list is a bit more nuanced than that, however, and those nuances will largely determine which of these models is best suited for your practice.

A carbon monoxide meter has up to three ways to alert you to the presence of carbon monoxide. It can do so visually, providing you with a flashing light or a digital readout informing you about the specific level of carbon monoxide present. It can do so audibly, sounding a beep in the presence of carbon monoxide, the intensity of which may correlate to the concentration of the gas. It can also alert you physically, vibrating against your hip or in your hand much like your cell phone would.

This can give you a sense of how the gas levels in a given area have changed over time, which allows you to adjust your action plan accordingly.

Depending on where you work and who you work around, you may want all or none of these features to be activated. Whatever the case, look for a unit who's alarms are either customizable enough for you to dial them in for the setting or task at hand, or whose features are specifically appropriate to the area in which you do most of your work.

Other important features to look for include memory recall, battery life, and durability. Memory recall will give you the ability to compare current readings to readings taken previously, whether they were taken an hour ago or a week ago. This can give you a sense of how the gas levels in a given area have changed over time, which allows you to adjust your action plan accordingly.

Battery life may speak for itself, but it's important to know whether the model you're interested in has a built-in rechargeable battery or runs on replaceable, disposable batteries. This is largely a matter of preference, but if you're the type to ignore the need to recharge your meter, it may prove useless to you when it's dead in the field.

Finally take a look at durability. If you work in a garage and you only take your carbon monoxide meter out once in awhile to check the levels in the air, you probably don't need the most durable model on the market. If, on the other hand, your job takes you to more treacherous environments that could pose a hazard, either from drops or bumps, then a model with some kind of durable housing is essential.

Will Rhoda
Last updated by Will Rhoda

After deciding that the pen was mightier than the pliers, Canadian electrical contractor William Rhoda abandoned his career and headed back to college, where he majored in marketing and advertising and won a scholarship along the way to earning a diploma in creative communications. His past career landed him a depth of knowledge in tools and hardware, while his current career schooled him in audio, video and camera equipment. During his leisure time, he’s learned lots about outdoor gear, and years of tiresome backyard maintenance have taught him all about pools and hot tubs. His recreational pursuits include rest, relaxation and revolutionary action, and his roommate’s a hairless cat.

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