CRITICAL FLAW ALERT!
This meter and its push probe accessory exhibit a critical flaw—namely the inability to obtain results below 8% moisture content. This flaw renders the meter and its push probe accessory essentially unusable for a number of common applications, including for flooring installations and furniture making. We deducted two stars from our overall rating to reflect these critical flaws.
This is a pin-style wood moisture meter that features a cabled pin probe accessory. Test results in this review focus on the use of the cabled accessory.
The meter is reasonably simple-to-use and offers an easy-to-read digital readout. However, the MM70D should not be relied upon for measuring wood with MC levels below about 8% MC, even though the manual states that it is able to take measurements as low as 5.5% MC.
It is designed for both wood and other building materials. Adjustments are possible for different species of wood using the table included in the manual.
- Simple-to-use with large, easy-to-read LED display
- Features data hold button and built-in calibration check
- Capable of measurements in a variety of building materials
- Unable to take readings below about 8% MC
- Readings affected significantly by surface moisture and meter temperature
General MM70D Wood Moisture Meter
Objective Evaluation – Overall Score 3.5 out of 5.0
Accuracy – 4.0 out of 5.0
This meter scored reasonably well for accuracy when compared to ASTM D4442 oven dry standards. In our testing, this meter was unable to obtain readings below about 8% MC even though the manual states that it can obtain readings to 5.5% MC.
Learn about our accuracy test procedures
Surface Moisture – 1.0 out of 5.0
Surface moisture caused this meter to post readings about 9% higher than the baseline. These surface moisture results indicate that operating this meter in high humidity environments where condensation may form on the surface could lead to questionable readings.
Learn about our surface moisture test procedures
Meter Temperature – 2.3 out of 5.0
Meter temperature had a significant effect on this meter’s MC readings. A low-temperature reading of 34.8° F in the presence of low MC increased the reading by about 0.5%, and in the presence of high MC decreased the reading by 2% MC compared to the room temperature reading.
A high meter temperature of 110° F in the presence of low MC increased the reading by about 0.8% MC compared to the room temperature reading. In the presence of high MC, the reading decreased by 2% MC compared to the room temperature reading.
Learn about our meter temperature test procedures
Wood Temperature – 4.7 out of 5.0
Wood temperature affected this meter’s readings, but not by large amounts.
A low wood temperature of 33.6° F in the presence of low MC showed only a small decrease in the reading, and in the presence of high MC showed nearly a 2% decrease when compared to the room temperature reading.
A high wood temperature of 110° F in the presence of low MC showed only a very small increase in the reading when compared to the room temperature reading. In the presence of high MC, the reading increased by almost 1%.
Learn about our wood temperature test procedures
Reading repeatability – 4.0 out of 5.0
The readings of this meter were mostly repeatable, with only a slight tendency to vary.
Learn about our repeatability testing procedures
Drift – 5.0 out of 5.0
Readings for this meter showed little tendency to drift, with readings that were only slightly lower after three seconds.
Cable Interference – 4.0 out of 5.0
The General MM70D’s cabled pin probe accessory demonstrated few problems with cable interference with only a slight decrease in MC readings.
Learn about our cable interference and drift testing procedures
Subjective Evaluation – Overall Score 3.4 out of 5.0
Learn about our subjective testing procedures
Ease of Use – 3.5 out of 5.0
This meter is relatively simple to operate. Four buttons mean it is necessary to consult the manual in order to understand all the available options. Documentation provided in the manual is adequate.
Quality – 2.3 out of 5.0
This meter is not exactly intended for the budget-conscious individual. However, it has a lower quality appearance, and we found the meter’s casing to be subject to breakage during our testing. Using the supplied pins can be frustrating because they are subject to bending or breaking too.
Comfort – 3.5 out of 5.0
This meter has an ergonomic design that is comfortable to hold, the display is easy-to-read and the four control buttons are relatively easy to use. No carrying case is provided.
Versatility – 3.0 out of 5.0
This is a pin-style meter only that is not capable of adjusting for species. An advantage of using the cable accessory is that data does not need to be viewed upside down while the probe’s pins are inserted into the wood sample.
Range – 3.7 out of 5
Measures moisture content from 5.5% to 50%, at least in theory. In practice, our tests indicated that no readings can be obtained reliably below about 8% MC.
Features – 3.5 out of 5.0
Readings precise to the nearest 0.1%. Low battery indicator. Offers an easy calibration check and a HOLD function for use in tight spaces where the display cannot be easily viewed. No meter re-calibration offered by the manufacturer.
Customer Service – 4.0 out of 5.0
General offers free replacement if anything goes wrong in the first year. No service center is available for repairs, nor does General offer any calibration services for its meters. Response to telephone inquiries is fast and friendly.
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.