Best Handheld CO Meter (under $100)

Carbon Monoxide, Carbon Monoxide Detector, CO Meter -

Best Handheld CO Meter (under $100)

Carbon monoxide (CO) is a tricky but deadly gas. It is elusive and difficult to track down as it cannot be sniffed out by the human nose. Many customers purchase CO meters to find a carbon monoxide leak or check for safe levels in the home, car, office or work and also help to determine if CO level are exceeding OSHA, WHO, NIOSH or ACGIH CO Threshold levels. Handheld portable CO meters are very popular and very affordable. Many are available on Amazon.com and Walmart.com, but it can get tricky to make a selection. Which is the best CO meter? Here we will provide some guidance and key features of what to look for when selecting a CO meter under $100. 

Pros

Cons

  • CO meters are affordable and good choices exist under $100
  • Carbon Monoxide meters are handheld units that provide users with the instantaneous CO concentrations
  • Helpful in detecting leaks, indoor air quality and possible CO leakage pathways
  • Typically more sensitive and faster than UL2034 home CO detectors and CO alarms
  • Hard to objectively compare CO meters
  • Requires expensive USA NIST Calibration gas reference to test accuracy
  • Some cheap options may be good for some applications
  • Carbon monoxide is a deadly killer and should be taken very serious

The Best Handheld CO Meter for under $100?

We have tested 5 popular CO meters from Amazon.com and Walmart.com. We undertook a systematic analysis that included:

  • traditional unboxing to see each CO meter, associated accessories and documentation
  • performed a functional test to observe the ergonomics, functionality, and intuitive operation of the CO meter
  • performed an accuracy test to NIST traceable carbon monoxide reference gas (196ppm)

Each CO Meter was highly ranked and below $100.

Our ultimate objective in doing this test is to walk you through the items to consider, questions to ask and first hand information to help with you knowledgeable selection when purchasing a handheld CO meter.

#5 DOEATOOW CO Carbon Monoxide Detector 

Price: $60-$80
Accuracy: 
⭐⭐
Functionality: ⭐⭐⭐⭐⭐

  • This is a reasonable option as a handheld CO tester. Unfortunately, in our testing, it did not maintain a steady state CO level when exposed to NIST CO reference gas - it had a slight drift towards the downside.
  • Advanced functions such as alarm setting and calibration which is a huge plus.
  • Excellent value for money, this CO meter comes with a made in UK sensor with USB recharge.
  • There is no NIST USA traceability documentation, no date of manufacture, and no test engineer QC signature.

#4 Carbon Monoxide Meter PCMM05 - Pyle USA

Price: $80-$100
Accuracy: 

Functionality: ⭐⭐⭐

  • A popular brand that has been around for many years.
  • Offers basic functionality but overly sensitive and the least accurate unit that was tested.
  • Comes with an excellent made in Japan sensor from Nemoto, but seems the detector is calibrated to read "too sensitive". 
  • Also another annoying thing was that the unit arrived with a dead battery.
  • There is no NIST USA traceability documentation, no date of manufacture and no test engineer QC signature.

#3 SMART SENSOR Handheld Carbon Monoxide Meter 

Price: $30-$40
Accuracy: 
⭐⭐⭐
Functionality: ⭐⭐⭐

  • Another famous model that is the best bang for buck when it comes to CO meters.
  • Offers basic functionality, comes with an excellent made in Japan sensor from Nemoto and is very accurate within specifications.
  • For those on the slimmest budget, this is the unit to grab and you will not be disappointed.
  • Documentation is not consistent, but may just be nuisance typos.
  • There is no NIST USA traceability documentation, no date of manufacture and no test engineer QC signature.
  • Unfortunately, the ergonomics of the unit are not the best, it does feel like a toy to the touch and did not arrive with any batteries.

#2 Klein Tools ET110 CO Meter, Carbon Monoxide Tester

Price: $90-$100
Accuracy: 
⭐⭐⭐
Functionality: ⭐⭐⭐

  • A very popular and trusted brand in the tool industry.
  • A unique model and operated within specification, but under represented when tested to the reference CO gas.
  • I personally love the feel of the unique as it has a rubberized case and comfortable feeling.
  • A bit too long in length for my preference.
  • Offers basic functionality with temperature and averaging for STEL.
  • Comes with a made in Japan sensor (largest form factor compared to the others) from Figaro (5 year sensor), which is the worlds oldest and most famous gas sensor company. 
  • There is no NIST USA traceability documentation, no date of manufacture, and no test engineer QC signature.

 

#1 Forensics Detectors Carbon Monoxide Meter

Price: $90-$100
Accuracy: 
⭐⭐⭐
Functionality: ⭐⭐⭐

  • Has all the bells and whistles features like all other tested
  • Most important comes with the USA NIST traceability documentation, and the only unit at this price point.
  • The most accurate unit tested, only off by 1ppm to the reference gas used in the testing.
  • A bit more pricey due to extra work needed to calibrate to NIST standards and produce the USA certificate, since some customers need it for OSHA or regulatory evidence of calibration.

 

 

What Is the Difference Between a CO Meter and a CO Detector?

A CO meter is a handheld portable unit that detects CO gas at lower ppm concentrations that a typical UL2034 home ceiling CO detector or CO Alarm. A CO meter is a great tool to use to locate, detect and sniff a potential CO leakage source or pathway.

CO Detectors used for home wall or ceiling mount applications that comply with UL2034 are not designed to display CO concentration less than 30ppm (that is just part of the UL2034 requirement).

In addition, a CO detector or CO alarm operates very "slowly" since its refresh rate is very low to conserve battery power. Also they may alarm slow since the first alarm threshold at 70ppm only triggers after a minimum of 60 minutes.

Who Uses a CO Meter?

Homeowners and Landlords

Many homeowners and landlords when suspecting a CO leak purchase a CO meter to test and sniff a potential carbon monoxide source. Similarly, RV, campers and transport personnel also do the same to ensure maximum safety.

Plumbers and HVAC

Plumbers and HVAC professional are also major purchasers of CO meters. They use this tool to confirm any cracked heater exchanges, correct ventilation, backdrafting or CO accumulation. Also helps to confirm correct appliance installation.

Industrial Hygienists

Industrial hygienists perform indoor air assessments and tests and when dealing with carbon monoxide cases they will use a CO meter or analyzer to gather necessary data to find a leak, analyze indoor air quality or determine accumulation dynamics and carbon monoxide movement.

Regulatory Inspectors, First Responders, EMS

City, County and State authorities including paramedics and first responders are frequent users of CO meters. They use them for various requirements. For example, EMS personnel use them to protect themselves to ensure they are not entering a "self harm" toxic environment. City inspectors use them to ensure public facilities are safe to occupy.

Building Maintenance Technicians

CO meters are also often used by building maintenance crews. They can track accumulation of carbon monoxide in garages, facilities, pool heater rooms and other "common" CO leakage sites to ensure maximum safety of workers and occupants. 

Work Safety Officers

Many companies employ dedicate safety teams, health safety and environment officers and safety specialists that are responsible to ensure all workers in an industrial, manufacturing or occupational space are safe. Regular inspections are required that include rudimentary Carbon Monoxide measurements with CO meters. Such work is particularly important in industries where combustion is occurring, manufacturing or carbon monoxide is a known affluent or by-product. Another important part is using gasoline power tools on construction sites such as saw, generators, mixers, forklifts and many other machinery that emit exhaust carbon monoxide.

Recreation, Camping, Ice Fishing

Situations where recreational activities call for propane or butane heating and cooking appliances to be used in a confined space such as camping, ice fishing and many others pose a serious threat. Use of a CO detector and a CO Meter, to determine dangerous CO indoor air quality levels is very helpful.

Do I Need a Carbon Monoxide Detector or a CO Meter?

It depends on your application. 

CO Detector uses typically include:

  • Home ceiling and wall mount application where a CO detector is required by state, city or county authorities. In most areas, CO alarms (UL2034) are mandatory for home owners and landlords to install in the home
  • Home use for continuous protection

CO Meter uses typically include:

  • CO concentration indoor check for OSHA, NIOSH, WHO, EPA or ACGIH threshold checks
  • Suspect appliance leaking or poor indoor air quality checking
  • See prior question discussing who uses a CO meter.

What Levels of CO are Dangerous? 

The safest CO level is zero ppm. If there is CO that is detected by a CO Meter or a CO Detector, then it means you have a carbon monoxide leak, carbon monoxide accumulation or carbon monoxide entry into your indoor area. If there is a recording of any CO, then a change in circumstance, CO can quickly increase to dangerous levels. There are some guidelines that can be used as a safety reference. The science is changing and more low level CO exposure data is coming to light. A summary from various safety and air quality organizations are listed here:

Agency

Limits

World Health Organization (WHO)

9 ppm average over 8 hours

Environmental Protection Agency (EPA)

The Clean Air Act requires EPA to set national ambient air quality standards (NAAQS)

9 ppm average over 8 hours

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)

9 ppm average over 24 hours

National Institute for Occupational Safety and Health (NIOSH)

35 ppm average over 10 hours

200 ppm ceiling value

Occupational Safety and Health Administration (OSHA)

50 ppm average over 8 hours

American Conference of Governmental Industrial Hygienists (ACGIH)

25 ppm average over 8 hours

CO Detector Alarming Protocol
UL2034 (USA)

> 70 ppm (60 to 240 minutes)

> 200 ppm (10 to 50 minutes)

> 400 ppm (4 to 15 minutes)

CO Detector Alarming Protocol
EN 50291:2001 (Europe)

> 50 ppm (60 to 90 minutes)
> 100 ppm (10 to 40 minutes)
> 300 ppm (3 minutes)

Forensics Low Level Carbon Monoxide Detector

> 25 ppm (1 minute)

How Accurate Are CO Meters?

Typically the accuracy of a CO meter is specified in the CO user manual. These values vary. They way in which accuracy is specified and communicated to the user also varies. These numbers should also be taken with a grain of salt since our internal testing (see the video above), shows large variance. Some detectors do not comply with their own accuracy specifications. Nevertheless, accuracy specs are typically presented in three ways:

Absolute ppm Error Reading

  • Example: accuracy: +/- 10ppm
  • In this example, a simple +/-10ppm blanket error is stated. This means that if your CO meter is reading 100ppm, then the actual reading is expected to be between 110ppm to 90ppm.

Percentage Error Reading

  • Example accuracy: +/- 10% (of the reading)
  • In this example, a percentage of the reading is stated. If your CO meter is reading 200ppm, then the actual reading should be expected to be either +/- 10% of 200ppm. Which is between 220 ppm or 180 ppm.
  • If a blanket percentage is provided, be skeptical. The manufacturer should have been more specific and the follow up question to that spec would be, "...is the accuracy % of the reading or of the full scale?".

Percentage Full Scale Error Reading

  • Example accuracy: +/- 5% F.S. (full scale error)
  • In this example, the error is based on the full scale range of the detector. For example, if the detector is rated at 0-1000ppm and it is reading at 100ppm, then 5% of 1000 ppm is 50ppm, hence the reading could be between 150 to 50ppm.
  • Although this sounds very large and "really bad", most detectors fail error readings since temperature and humidity and the largest error sources, especially in the extreme ends of the temperature and humidity specifications.  
  • Most CO Meters (and other toxic gas detectors) use this scale to reference accuracy and error.

Do CO Meters have Alarms?

Most CO meters do have alarms. They are typically set to the OSHA, NIOSH, EPA or ACGIH CO exposure thresholds. Typical alarms include LED, buzzer and vibration. A solid CO meter will have all three types of alarms for added safety - think about using it in a mine which is very noisy and clipped to your pocket so you may not see it. In that case, the vibration alarm may save your life. Some CO meter allow the user to change the alarm thresholds.

What is the Difference Between a CO and CO2 Meter?

Never confuse CO and CO2. They are both totally different gases. A carbon monoxide meter does not measure carbon dioxide gas and a carbon dioxide meter does not detect carbon monoxide gas. CO and CO2 are completely different gases and require specific meters to detect each respective gas.

Should a CO Meter Read Zero?

Yes it should but not all CO meters have the zero calibration function.

Zeroing a CO meter means to force the unit to read zero when it is in a zero carbon monoxide environment - typically done in the fresh outdoor air. Sometimes you will notice your CO meter flickers between 0,1,2,2,1,0,2, etc... or it may stay at 2ppm when in the outdoor air. Assuming the outdoor air is fresh and has no CO, then the CO meter should be zeroed to improve its accuracy.

Also if you are curious what your outdoor CO level is, we recommend checking it here.

Step 1: Get yourself a good CO meter.

Step 2: Make sure it works. Give it a bump test. 

Step 3: Turn it ON. Most CO meters start operating and showing you the instantaneous CO ppm reading. It should read 0 ppm.

Step 4: Take it to the desired indoor areas for testing. Keep it stationary for at least one minute to obtain stable readings. Ensure you are not breathing on it, nor changing temperature or humidity. Do not stick it in the oven, expose it to chemicals, exhaust or any "harsh" dynamic change in environment - why? it will react and give you false CO readings. The CO sensor element is very sensitive and fragile.

Step 5: Take photos or videos if you want to send any of the test results to somebody.

How Do You Test the CO Meter Accuracy?

To test the accuracy of your CO meter you need to use a reference gas. This would be USA NIST traceable source gas that can be purchased from various gas companies including from us (supplied via GASCO). This is how you do it:

Step 1: Order CO gas. For example, 200ppm of CO gas.

Step 2: You will receive your calibration gas cylinder. The COA will tell you the exact CO level made. It is never exactly the same as ordered, just a bit off. It could be 204ppm.

Step 3: You may need to use a calibration cap, hood to deliver the gas to the sensor. Deliver the calibration reference gas to the sensor. Allow the sensor to stabilize for about 1 minute and take your reading. 

Step 4: Assume the reading is 210ppm. Then the CO meter is 6 ppm away from 204ppm. This is a 2.9% error compared to the reading. Or it can be interpreted as a 0.6% error to full range (F.S.) if the CO meter has a range of 0-1000ppm.

How Much Do CO Meters Cost?

An excellent CO meter will cost no more than $100. However, if you need a CO meter with a built in pump, it is more expensive and will cost about $300.

Where Can I Buy A Carbon Monoxide Meter?

CO meters are readily available online from Amazon.com or Walmart.com. Also a tonne of products options, for all applications are available from us.

Final Words

  • CO meters are affordable and good choices exist under $100
  • Carbon Monoxide meters are handheld units that provide users with the instantaneous CO concentrations
  • CO Meters are helpful in detecting leaks, indoor air quality and possible CO leakage pathways. Also excellent to determine if any OSHA, EPA, NIOSH or ACGIH level have been exceeded
  • Typically more sensitive than home CO detectors complying with UL2034
  • Hard to objectively compare CO meters unless you have USA NIST Calibration reference gas
  • Some cheap options may be good for some applications
  • Carbon monoxide is a deadly killer and should be taken very serious 

About The Author

Dr. Koz is the President of FORENSICS DETECTORS where the company operates from the scenic Palos Verdes Peninsula in Los Angeles, California. He is a subject matter expert on gas sensor technology, gas detectors, gas meters, and gas analyzers. He has been designing, building, manufacturing, and testing toxic gas detection systems for over 20 years.

gas detector expert

Every day is a blessing for Dr. Koz. He loves to help customers solve their unique problems. Dr. Koz also loves spending time with his wife and his three children going to the beach, grilling burgers and having a cold beer. 

Read more about Forensics Detectors here.

Email:  drkoz@forensicsdetectors.com
Phone: +1 424-341-3886


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