How to Avoid Common Mistakes with a Moisture Meter
Getting ready to use your wood moisture meter for the first time?
Or perhaps you’ve been using one and running into problems.
You’re not alone! That’s why we want to equip you with the know-how to avoid mistakes that skew moisture meter readings. You’ll know how to use a moisture meter properly and be on your way to greater success in your projects.
We’re going to dive into the following:
- Why accuracy is important when measuring moisture in wood
- 7 common sources of error when using a moisture meter
- How to avoid common mistakes with a moisture meter
Let’s start by understanding the importance of measuring moisture in wood accurately.
Why accuracy is important when measuring moisture in wood
Accuracy is important when measuring moisture in wood because it can mean the difference between a successful project and a damaged one.
Moisture has the potential to ruin a wood project because it causes the wood to change shape.
But if the wood stays in an environment with the same temperature and relative humidity, it will eventually attain a stable moisture level—known as the equilibrium moisture content (EMC).
For best results when woodworking, the wood should already be near or at the EMC for its final destination.
That’s why you need accurate moisture readings of the wood before using it. You’ll be able to determine whether the wood has reached the EMC and is ready for use.
Then you’ll avoid problems such as:
- Drawers in cabinets sticking
- Doors not closing properly
Accurate moisture meter readings will give you the confidence to move forward with your wood project, knowing that it won’t be ruined by moisture.
7 common sources of error when using a moisture meter
Even the best of us make mistakes! See if you might be doing any of these and sabotaging your results:
1. Using the wrong moisture meter
When working with wood, make sure that you have a wood moisture meter (as opposed to a concrete moisture meter or a soil moisture meter).
You’ll also need to decide which type works best for your purposes: a pin meter or a pinless meter.
For example, a wood flooring specialist may not want to use a pin meter, which will poke holes in the boards and affect their appearance.
To learn more about which meter is right for you, read our guides on pin meters and pinless meters.
2. Failing to enter the correct species number
Most wood moisture meters have a feature that allows you to enter a number for each species of wood that is being used.
If you don’t put the right species number in, you’re setting yourself up for an inaccurate reading. The reason for this is that different species exhibit different wood densities that can affect the meter’s readings if you don’t take this into account.
3. Failing to correct for temperature
If you have a pin-type meter, failing to correct for temperature (if significantly different than room temperature) can lead to a false result.
With a pinless meter, such as the ones made by Bessemeter, you don’t have to worry about this issue.
4. Testing on wood that has surface moisture
Measuring moisture content on a surface that has water can affect the reading. Some meters—both pin and pinless—are much more sensitive to surface moisture than other meters.
Even if it’s just some dew, it can still make a difference, particularly for a pin meter.
How does this happen?
A pin meter measures the electrical resistance between two pins to determine moisture content. It will pick up on moisture anywhere between those two pins—even on the surface.
5. Not measuring at the right depth
If you don’t measure moisture content at the right depth, you may miss detecting a moisture level that could cause problems for your project. Wood is often drier on its surface and wetter in the middle. Thus, you may get a reading that tells you the wood is dry, but in reality, you’ve only tested near the surface and missed the wet wood deep in the board.
For pin meters, this issue can occur if you don’t have pins that are long enough to reach the middle of the wood.
6. Not measuring on a flat surface
When using a pinless meter, uneven surfaces can mess up your moisture readings.
The sensor plate of a pinless meter must be firmly pressed against the wood. If the piece of wood is too small or has a lot of knots and unevenness, your reading won’t be accurate.
7. Not checking for metal in the wood
Any kind of metal in the wood can skew moisture meter readings. Keep an eye out for nails or metal strips especially if you are measuring moisture in buildings.
How to avoid common mistakes with a moisture meter
It’s important to know what to do and what not to do when it comes to a wood moisture meter. Here are some simple steps to avoid the common mistakes:
Maintain your meter.
Keeping your meter in good working order will go a long way to ensure you get accurate results.
Clean it regularly and store it in its protective case.
And please, don’t leave it exposed to the elements. Just because it’s a moisture meter doesn’t mean that it can handle getting rained on! Water can damage the internal circuitry of the meter.
Finally, be sure to occasionally verify the calibration of your meter, using a calibration reference tool. If you’ve dropped the meter, verify calibration again to be sure it is still reading correctly.
Read and follow the manual.
Every moisture meter is a little different, so read its manual and follow the manufacturer’s instructions.
Research your project.
Make sure you understand the requirements for the specific project you are working on. Know the required moisture content and any other industry-specific standards.
For wood flooring, the NWFA (National Wood Flooring Association) offers such guidelines.
Correct for species and temperature.
With either pin or pinless meters, input the correct species number for the wood you’re using.
For pin meters, correct for temperature if the wood is significantly different than room temperature. Some moisture meters have a way to enter the temperature of the wood into the meter so it can make corrections. If yours does not, use a temperature correction chart.
Check that your surface for measuring is dry.
Because surface moisture can skew your results, be sure to check for any water before you measure. If necessary, wipe the wood and allow it to dry.
With a pin meter, consider using insulated pins, which only read from their tips. They’ll allow you to bypass the surface moisture.
Be careful with how you hold the meter.
If you’re using a pin meter, don’t rock the meter as this can break the pins. But sometimes they break even for the most experienced woodworkers, so keep tools and extra pins on hand for changing them.
When you’re using a pinless meter, make sure that you firmly press the sensor plate on a flat part of the wood.
Take many readings in various places.
Measuring in only one place may give you an accurate reading for that location, but it may not indicate what the rest of the wood is like.
This is why you should take multiple readings of the wood in different locations and on different pieces, especially if you’re doing a large project.
The NWFA recommends measuring 40 boards for every 1,000 square feet of flooring.
You’re ready to get accurate results with your moisture meter.
Now that you know the common moisture meter mistakes and simple steps to avoid them, incorporate wood moisture measuring into your workflow.
You won’t regret it!
You’ll say goodbye to moisture-related damage! And best of all, you’ll boost the quality of your work to a level you’ll be proud of.
But being precise in your use of a wood moisture meter isn’t enough if you’re using a low-quality moisture meter. See which one of Bessemeter’s highly accurate meters might be best for you.