Meter Temperature Test
Another factor that could affect a moisture meter’s accuracy is the temperature of the meter itself. The rationale behind the Meter Temperature Test is to determine each meter’s sensitivity to changes in meter temperature.
In other words, if a meter is sensitive to meter temperature, will it require the user to correct for it?
And, if the user needs to correct his meter but doesn’t, how much will it affect accuracy? While many higher-end manufacturers normally have a temperature correction chart for their meters, this allows the user to compensate only for the temperature of the wood, not the temperature of the meter.
Unfortunately, most people who use moisture meters are not aware of their meter’s limitations and how those limitations affect meter performance.
Consider the user who leaves his meter in his garage or truck in the summertime, where the temperature could get up to 100° F. If he brings his hot meter inside to an air conditioned environment for either a woodworking or flooring project, he may need to wait an hour or more to allow the meter temperature to cool off to room temperature.
Should he begin to use his meter immediately, the temperature differential between the meter and the room could result in readings significantly inaccurate. A similar scenario could occur in winter time, where the cold lowers the meter’s temperature.
Meter temperature normally affects pin meters more than pinless meters. It’s important for users to understand that they may need to adjust their meters to compensate for high or low meter temperatures.
Although the higher-end meters normally have a Temperature Correction chart that takes into account meter temperature differentials, they are often difficult to read quickly. For that reason, it’s probably safe to assume that many people just skip this step.
Moisture Meter Temperature Test Procedures
- Take three pieces of Douglas fir, one piece between (5%-10%), one piece between (11%-20%), and one piece (greater than 20%).
- With each meter, take a reading of each of these pieces at room temperature and record both the meter reading of the wood and the meter temperature.
- Put the meters in the refrigerator for one hour.
- Record the meter temperature and take a reading of the first piece of wood with each meter, and for pinless meters, take a reading with the meter in the air. Record.
- Repeat step 4 with each piece of wood.
Cooling Meters in the Refrigerator