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Picture of the Extech MO280 Pinless Moisture Meter
Our Score:
Extech MO280 Pinless Moisture Meter

This meter exhibits a critical flaw—namely its very low score for accuracy. We deducted one star from our overall rating to reflect this critical flaw.

The Extech MO280 is less accurate than most of the wood moisture meters that we tested. It is a pinless meter equipped with electromagnetic technology that facilitates quick measurement of the moisture content in wood and other building materials.

Our testing revealed significant drawbacks with this meter, namely inaccurate readings when moisture content exceeds 8%, as well as highly-inflated readings when moisture is present on the surface of the wood sample.

The MO280 features a comfortable, ergonomic design, a HOLD function for working in tight spaces, and an alarm that alerts the user that readings are outside the meter’s range.


  • Built-in species adjustment when selecting from 10 wood group settings.
  • Fast, easy to use, and comfortable ergonomic design.
  • HOLD function for use in tight spaces.


  • Among the least accurate wood moisture meters we tested.
  • Surface moisture significantly affects readings.
  • Audible alarm beeps with every new reading and can be irritating.
  • Repairs are expensive and come with only a 60-day warranty.

Objective Evaluation – Overall Score 3.0 out of 5.0

Objective test summary results for the Extech MO280 pinless moisture meter, achieving objective score of 60%

Accuracy – 2.6 out of 5.0

This meter is highly inaccurate when compared to ASTM D-4442 oven dry measurements. This meter showed some degree of accuracy in the low MC range (5% to 8% MC), but readings above 8% were not very accurate.

Extech MO280 Accuracy Test Results

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Surface Moisture – 1.0 out of 5.0

After applying slight moisture to wood, the Extech MO280 showed extremely inflated readings. As a result, this meter is probably not suitable in situations where condensation occurs on the surface of the wood sample.

Extech MO280 Surface Moisture Test Results

Learn about our surface moisture test procedures

Meter Temperature – 2.5 out of 5.0

Meter temperature had an effect on this meter’s readings.

A low meter temperature of 34.8° F in the presence of low MC increased 1% compared to a room temperature of 70.5° F. In the presence of high MC, the meter was incapable of taking a reading.

A high meter temperature of 110° F in the presence of low MC increased the reading by only 0.2% compared to room temperature. In the presence of high MC, the meter again was incapable of getting a reading.

Bar chart showing that meter temperature had an effect on the Extech MO280 meter readings

Learn about our meter temperature test procedures

Wood Temperature – 3.0 out of 5.0

Wood temperature had little or no effect on this meter’s readings.

A low wood temperature of 33.6° F in the presence of low MC gave a reading only 0.1% higher than a room temperature of 71.8° F. In the presence of high MC, the meter was incapable of taking a reading because the moisture content was beyond its range.

A high wood temperature in the presence of low MC had the same reading as room temperature. In the presence of high MC, this meter was incapable of taking a reading.

Bar chart showing that wood temperature had little or no effect on the Extech MO280 meter’s readings

Learn about our wood temperature test procedures 

Reading Repeatability – 4.0 out of 5.0

Extech MO280 moisture content readings were mostly repeatable.

Extech MO280 Reading Repeatability

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Drift – 5.0 out of 5.0

Readings taken after 3 seconds drifted slightly.

Bar chart showing that Extech MO280 pinless meter readings taken after 3 seconds drifted slightly

Cable Interference – N/A

This meter is pinless and does not have a hammer probe accessory.

Blank chart stating that the cable interference test isn't applicable to the Extech MO280 pinless wood moisture meter

Learn about our cable interference and drift testing procedures

Subjective Evaluation – Overall Score 4.0 out of 5.0

Subjective test summary results for the Extech MO280 Pinless moisture meter, earning a subjective score of 79%

Learn about our subjective testing procedures

Ease of Use – 3.2 out of 5.0

This meter is simple to operate with only minimal use of the manual needed to get started. However, documentation in the manual is not as comprehensive as it should be, and inexplicably instructs the user to switch species settings when measurements are outside the acceptable range for a particular wood group.

Quality – 4.3 out of 5.0

Solid and durable, this meter appears unlikely to malfunction or break with normal use. However, the disappointing results when tested for accuracy suggest that quality has been compromised in some respects.

Comfort – 5.0 out of 5.0

Lightweight and comfortable to hold with rubberized grips along the side. Fits comfortably into a jacket or shirt pocket. Comes with a soft case that can be attached to a belt.

Versatility – 3.0 out of 5.0

This is a single-mode meter (pinless), which is typical. Features built-in species adjustment for specific gravity that uses ten categories for wood and other materials. The manufacturer states that this meter works on a variety of building materials. However, we evaluated this meter’s performance only for wood and did not test its accuracy when used with other materials.

Range – 5.0 out of 5.0

The manual indicates that this meter has a range from 0.4% to 63.2%. The range varies somewhat, depending on the species group. For example, for Douglas fir and for pine species, the range extends down only to 6.7%.

Features – 3.2 out of 5.0

Readings precise to the nearest 0.1%. Low battery indicator. Features a HOLD function that “freezes” readings until display can be viewed, which is handy when working in tight spaces. Also features an audible alarm that beeps every time the reading changes, which is an irritation when taking multiple readings, or whenever the reading is outside the meter’s capability.

Customer Service – 4.0 out of 5.0

Customer service appears knowledgeable and is able to answer all the basic questions, including the cost of repairs, turnaround time on repairs, etc. Prompt response provided to telephone calls, but the response time to our email inquiry was over 48 hours. The meter comes with a 1-year warranty. The repair warranty is only 60 days.

Our review is based on Moisture Meter Experts independent evaluation of the meter, which was purchased by Moisture Meter Experts or provided free of charge by the manufacturer. By purchasing this meter through the links above, Moisture Meter Experts may be compensated either by your purchase directly from Moisture Meter Experts or from commissions from an affiliate. View our Review Procedures section to learn more about our proprietary evaluation procedure and expertise in the field of moisture meters.