There are two types of wood moisture meters in use today, pin and pinless. This article focuses on the basics of pin moisture meters, the difference between pin and pinless meters, and then we review what we think are the top three pin-type moisture meters on the market today.
Pin Moisture Meters
Pin meters contain two pins (or probes) that must be pushed into the wood to take a reading. After the meter is turned on an electrical current flows between the two probes and measures the electrical resistance between them. Pin meter technology is based on the fact that water with salts and impurities conducts electricity while wood doesn’t. This means that drier wood will demonstrate more resistance to the current.
The length of the pins determines the depth of the reading and deep readings are done via an external hammer probe.
Although pin meters have been around since the very beginning and are a tried and true method for measuring moisture content, there are some downsides…
They aren’t the quickest way to measure wood moisture content.
This is because they only measure the resistance between the two pins. So, unless you’re measuring the moisture content of a very small piece of wood you’ll need to take several readings in order to get an accurate picture of the moisture content. This takes time, of course. Also, every reading with a pin meter pokes two unsightly holes in the wood.
The pins can either bend or break.
Some species of wood are so dense that it’s difficult to push the pins into the wood. When this happens the pins tend to either bend or break and then have to be replaced. If this happens a lot, the cost of replacing the pins can add up.
Differences Between Pin and Pinless Meters
The most obvious difference is the fact that pinless meters don’t need to poke holes in the wood in order to take a reading. This is because pinless meter technology involves an electromagnetic moisture sensor pad that’s able to simply glide over the surface of the wood in order to measure its moisture content. This difference means that you can take multiple moisture level readings using a pinless meter in no time flat.
Now, this doesn’t mean that pin-type meters are less effective at measuring wood moisture content. It just means that because of the technology they use, they’re not as speedy as pinless meters.
Other differences between pin and pinless meters include…
- Pin meters are sensitive to wood temperature. Because of this, all quality pin wood moisture meters will come with temperature correction charts. Some high-quality pinless meters are not sensitive to wood temperature unless the wood is frozen solid.
- Pin meters are sensitive to wood’s chemical makeup. This is why quality pin-style meters will ask you to enter the wood species prior to taking a moisture reading.
- Pinless meters are sensitive to wood density. Therefore, you’ll also need to enter the wood species prior to taking a reading with a pinless meter. (Wood density is also called ‘’specific gravity’’.)
While pin meters are good for measuring the moisture content of lumber and firewood, pinless meters are the best choice for expensive furniture and hardwood floors because they don’t damage the wood.
Top Pin Moisture Meters on the Market Today
There are quite a few quality pin-type wood moisture meters out there for sale. However, these are our top three picks…
1. Delmhorst RDM-3 Moisture Meter
The Delmhorst RDM-3 pin-style wood moisture meter has a rugged build, an intuitive, easy-to-use keypad, and the ability to store data and then download it to a computer. It’s also reasonably accurate (except for when moisture content falls below 8%). Since the meter was designed to measure the moisture content of wood only, you can’t use it to test the moisture content of other building materials.
The pros of the Delmhorst RDM-3 include the fact that it can store up to 1,416 readings that can be then downloaded to your computer. It’s well-built and has an adjustable alarm that lets users know when a preselected moisture content has been reached. There are also several external electrode accessories available.
Cons include the lack of a built-in calibration check, issues with accuracy when the moisture content falls below 8%, and the fact that surface moisture can significantly affect the readings.
2. Delmhorst BD-2100 Digital Pin Wood and Sheetrock Moisture Meter
The Delmhorst BD-2100 digital pin wood and sheetrock moisture meter measures the moisture content in wood, sheetrock, and a variety of other building materials. It can measure moisture content from 6-40%.
The pros of this meter include its ability to measure the moisture content of a variety of materials, not just wood. It can also run a calibration check, warn you if a moisture content reading is above a certain value, and store up to 100 readings and take the average of them.
Downsides include the fact that it can’t read moisture content below 6% and tends to produce moisture content readings that are slightly lower than the actual moisture content of the wood. Another con is the fact that surface moisture affects the accuracy of the reading. Finally, the pins aren’t that durable.
3. Protimeter Timbermaster Moisture Meter
The Protimeter Timbermaster pin moisture meter was designed for use in the wood products industry. Moisture readings can be taken using the pins or with various external probes including a hammer probe, a moisture probe, and/or a temperature probe.
The pros of the Protimeter Timbermaster include its ergonomic design, its ability to adjust for species, its ability to automatically adjust for temperature when using a probe, and the fact that it’s accurate up to 25% moisture content.
Downsides include the meter’s inability to take accurate measurements when the wood moisture content is less than 7% and the fact that moisture on the surface of the wood will significantly affect the results. It also doesn’t offer consistent, repeatable measurements.
Read the review: https://www.moisturemeter.com/ge-timbermaster-moisture-meter-review/
If We Had to Pick One of the Three…
While all of the above-mentioned pin meters provide accurate readings and are definitely worth the money, there’s one we like the best…
Delmhorst RDM-3 Wood Moisture Meter
In our opinion, the rugged Delmhorst RDM-3 moisture meter stands out because it’s reasonably accurate and allows you to store a large number of readings which can then be downloaded to a computer. While surface moisture can affect the accuracy of the readings, this is easily remedied by thoroughly wiping down the wood and then waiting for about 30 minutes before taking a reading.
If you’re planning on buying a wood moisture detector, you’ll want to make sure your buying decision is well-informed and based on facts rather than sales hype. Check out our review of the top moisture meters (both pin and pinless) for 2020.