GE Timbermaster Hammer Electrode

Our Score:

Bar chart showing overview of Protimeter Timbermaster Hammer Electrode scoring on objective and subjective tests

The GE Timbermaster’s hammer electrode is one of the accessories available for the Timbermaster meter. It facilitates measurement of moisture deep within the wood sample.

In spite of the slide hammer’s solid appearance, the electrode tended to malfunction during our testing. Several times the crimp broke off the wire inside the head of the electrode.

We also found that it provided measurements that were skewed to the high side of actual moisture content (MC).

Due to problems related to the quality of both the meter and its hammer probe accessory, we are unable to recommend either one.


  • Built-in scales for species adjustment
  • Readings adjust for temperature automatically when the temperature probe accessory is used
  • Ergonomically-designed meter


  • Moisture measurements tend to read somewhat high
  • Hammer electrode has wiring issues
  • Not capable of taking measurements when MC is less than 7%
  • Does not provide consistent, repeatable measurements

Protimeter TimbermasterProtimeter Timbermaster Moisture Meter

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Objective Evaluation – Overall Score 3.8 out of 5.0

GE Timbermaster Hammer Electrode objective

Accuracy – 4.4 out of 5.0

This meter’s hammer electrode provided only moderate accuracy, with readings that were somewhat high compared to ASTM D-4442 oven dry standards. It is not capable of taking measurements below 7%.

GE Timbermaster Accuracy

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Surface Moisture – 1.0 out of 5.0

The Timbermaster hammer electrode provided inflated readings in the presence of surface moisture. This indicates that operating this meter in high humidity environments where condensation may form on the surface could lead to questionable readings.

GE Timbermaster Surface Moisture Test Results

Learn about our surface moisture test procedures

Meter Temperature – 4.7 out of 5.0

Meter temperature had a small effect on this hammer electrode’s readings.

A low meter temperature of 34.8° F in the presence of low MC increased the reading by 0.6% compared to the room temperature reading. In the presence of high MC, the reading decreased by 0.3%.

A high meter temperature of 110° F in the presence of low MC lowered the reading by 1.1% compared to the room temperature reading. In the presence of high MC, the reading decreased by 1.3%.

GE Timbermaster meter temp graph

Learn about our meter temperature test procedures

Wood Temperature – 4.3 out of 5.0

Wood temperature has some effect on this hammer electrode’s readings.

A low wood temperature of 33.6° F in the presence of low MC increased the reading by 1.3% compared to the room temperature reading. In the presence of high MC, the reading decreased by 1.1%.

A high wood temperature of 110° F in the presence of low MC dropped the reading by 0.2% compared to the room temperature reading. In the presence of high MC, the reading increased by 1.4%.

GE Timbermaster Wood Temp Graph

Learn about our wood temperature test procedures 

Reading Repeatability – 3.0 out of 5.0

Readings taken with this meter are not entirely repeatable.

Line chart showing reading repeatability results for the Protimeter Timbermaster Hammer Electrode

Learn about our repeatability testing procedures 

Drift – 4.0 out of 5.0

Readings for this meter showed a small tendency to drift, with readings that were about 0.2% MC lower after three seconds.

GE Timbermaster Drift Graph

Cable Interference – 4.0 out of 5.0

Cable interference had a small effect on this hammer electrode’s reading.

GE Timbermaster Hammer Electrode Cable Interference

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Subjective Evaluation – Overall Score 3.4 out of 5.0

protimeter timbermaster hammer subjective

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Ease of Use – 3.2 out of 5.0

The hammer electrode is easy to use. With only two buttons to push, the meter itself is also simple to operate. Documentation in the manual is adequate but not as clear and easy to understand as one would prefer.

Quality – 3.7 out of 5.0

The slide hammer appears solidly built. However, we experienced problems with the electrode’s internal wiring. We found other issues that call into question the quality of the meter itself. For example, during testing, the inside screws that hold the wire connection to the pins came loose and caused inaccurate readings.

Comfort – 5.0 out of 5.0

The hammer electrode is comfortable to use. The meter itself is also ergonomically designed to fit nicely in one’s hand. It is compact and fits easily in a shirt or jacket pocket. Large, easy-to-read display.

Versatility – 2.0 out of 5.0

This is a single-mode meter (pin), which is typical. It is capable of internal species correction using eight built-in scales for wood species.

Range – 2.3 out of 5.0

This meter reads from 7% to 30% MC. It is not capable of measuring the MC of wood samples with a low MC below 7%.

Features – 2.8 out of 5.0

Readings precise to the nearest 0.1%. Low battery indicator. No HOLD function. Includes plug-ins for optional accessories including a hammer, moisture, and temperature probes, and a calibration check device.

Customer Service – 4.5 out of 5.0

Customer service appears knowledgeable and is able to answer all the basic questions, including the cost of repair, turnaround time on repairs, etc. Warranty is one year. Fast response time to both telephone and email inquiries. Manual available online.

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.