Wood Moisture Meters Buying Guide: Pinless vs Pin-type
Whether you’re constructing a building, laying down a floor, or crafting furniture, wood moisture levels matter. If you want your wood creations to enjoy a long life, you need to treat the wood right.
Neglecting the moisture content of wood means ruined projects:
- Warped cabinets
- Crowning or cupping of hardwood flooring
- Damaged instruments
- Unsightly dining tables
How horrible to have your name attached to a project that went wrong!
That’s where moisture meters come in.
And your work will only be as good as your least accurate meter. So, what’s in your toolbox? A pin-type? A non-damaging pinless?
Maybe it’s time for a new meter—but which one?
Are Moisture Meters Accurate?
Yes, but it greatly depends on the quality and brand of wood moisture meter.
As a hygroscopic material, the longevity of the wood’s physical integrity and aesthetic quality depends on your understanding of the wood’s moisture condition at the time you want to start working with it.
A superior wood moisture meter can be accurate within 0.1% of the wood’s moisture content. It also scores high on repeatability, which gives the user confidence that the moisture content readings are spot-on.
Lower-grade moisture meters are very inaccurate as numbers are misleading and changing.
The real question is: What qualifies as “accurate” as it pertains to a wood moisture measurement?
The accuracy of a hand-held meter is determined by comparing the hand-held meter’s moisture reading against the over-dry test results. The closer its reading is to the oven-dry test, the more accurate the hand-held meter is considered.
Yes, wood moisture meters can be accurate within 0.1% of the wood’s moisture content. Most digital moisture meters will only show readings with 1 decimal place. Lower-grade meters are very inaccurate.
What Does a Moisture Meter Do?
Moisture meters indirectly measure the moisture content in a piece of wood by measuring certain electrical properties within the wood.
Fortunately, there are wood moisture meters that work with great precision. A quality moisture meter provides an accurate reading for you to make smart decisions about when and how to use the wood.
But how does a moisture meter take its measurements? There are two main technologies used: Pinless and Pin-Type.
What is a Pinless Moisture Meter?
Pinless moisture meters work by using a sensor pad that works in contact with the wood surface but does not physically break or damage the surface to take a reading.
Pinless moisture meters typically provide the capability to measure moisture content from the surface down to .25″ or deep depth measurements to .75″.
How Does a Pinless Moisture Meter Work?
Pinless wood moisture meters work with electromagnetic wave technology by using sensor pads that lay flat on the wood.
Pinless moisture meters send out electrical waves at a certain electromagnetic frequency, which creates an electromagnetic field in the area under the sensor pad. The waves sent out by the sensor through the electromagnetic field trigger return waves the sensor detects.
These changes in wave movement data correlate to a moisture content percentage and provide accurate readings. Meters using this type of technology are called “pinless meters” because they don’t insert pins into the wood.
They’re also referred to as “non-damaging meters” because there is no need to penetrate the wood. No damage necessary for an accurate reading.
While pinless meters’ ability to read waves may be impacted by density variations in the wood, they are able to test a broader expanse of the wood and provide a more complete picture of its moisture condition.
What Is a Pin-Type Moisture Meter?
Pin-type moisture meters usually have two metal pins that must physically penetrate the wood’s surface in order to take a moisture reading.
How Does a Pin-Type Moisture Meter Work?
Pin-type moisture meters use resistance technologies.
Two probes, or “pins,” are inserted into the wood, and an electric current flows between the two pins. The amount of resistance detected in the current as it moves between the pins is an indicator of the moisture condition of the wood.
Because moisture conducts electricity well, the “wetter” the wood, the less resistance there is to the current flow. The drier the wood, the greater the electrical resistance is.
But pin meters’ accuracy can be affected by variations in the natural chemical composition of different wood species. A wood’s density doesn’t impact the flow of the current, but it can interfere with properly inserting the pins.
Which is better: Pin or Pinless Moisture Meters?
One of the benefits of a pinless meter is that it’s easier and faster to use than a pin meter. This allows users to have time to take enough readings to get a complete picture of the wood’s moisture level.
A pinless meter measures a wide swath of wood with each test, meaning fewer tests than using a pin meter.
The features of pinless meters also allow you to switch measurement depth faster. Higher quality pinless meters come with dual depth measurement options, typically at a quarter and three-quarter-inch depths.
The other main advantage pinless meters have over pin meters is that they don’t cause damage to the wood. Every measurement taken with a pin meter drives two holes into the wood. A pinless wood meter never breaches the surface.
One of the benefits of using a pin meter is that you can test at a wide variety of depths within the wood. Pins come in different lengths, so you can always swap out pins to measure at different depths.
Measuring for moisture at multiple depths creates a broader picture of the overall MC of the wood.
But that is not without its own challenges.
The challenge with pin meters is that accurate measurement depends on the pins being driven into the wood properly.
It can take a fair amount of pressure to get the pins inserted properly, especially the longer the probe. The denser the wood species, the more pressure required to properly insert the pins.
The accuracy of the pin meter can also be impacted by the wood’s temperature.
If pin meters are substantially hotter or colder than approximately 70 degrees F, they require their readings be compensated up or down depending on the exact temperature.
Another drawback is this: Pin meters only measure the moisture content of the small area between the two probes, which means multiple tests must be conducted at different spots. And even more tests if you want to switch out pins to measure at multiple depths.
What is the Best Moisture Meter?
Our choice for the best moisture meter is the Orion 950 pinless wood moisture meter.
But truly, it all depends on what you’re looking for as far as meters go. There are many different articles out there with their lists of the best moisture meters, but how can you tell if it’s the right one for you?
Here is your guide to wood moisture meters, so you can use them wisely and confidently on all your woodworking projects.
Do You Know Your Target EMC
The typical EMC to which wood will be exposed ranges from 7% to 19%. However, that’s too large a range to accept for a specific project.
Most wood flooring manufacturers dry the wood they use to between 6% to 9%.
The EMC applicable to a specific location depends on temperature and RH variations throughout the year in that region and how controlled the environment will be in the immediate usage area (i.e., is this wood for indoor or outdoor installation).
Wood being used for construction has a higher EMC range of 9% to 14%.
Again, this will vary by location and species and is just the typical range.
If you’re building in a dry city like Las Vegas, the local EMC can drop as low as 4%. But wood objects that will spend their lives indoors—anything from violins to tables—they’ll have a more predictable target EMC range of 6% to 8%.
How to Select the Best Wood Moisture Meter
Many people prefer a pinless moisture meter because they don’t want the probes to ruin the wood. The more tests run with a pin meter, the more damage it does to the wood.
Yet without running enough tests, you won’t get an accurate understanding of the wood’s moisture condition.
Quite a conundrum, isn’t it?
There also is no model of pin meter that can be recalibrated onsite.
Another area for comparison when selecting a moisture meter is the scope of “field features” you find valuable. Since the moisture measurement technology hasn’t fundamentally changed, the addition of high-value field features is how you can distinguish an advanced moisture reader from a simpler one.
Such features can include:
Just think of all the damage to the board from each test.
At each test site, pins need to be inserted properly into the wood, which is a common cause of pin or meter breakage.
The bottom line: the process of using a pin meter can be time-consuming, tedious, and exert stress on the physical meter, which tends to result in taking short-cuts when measuring moisture.
Short-cuts are never an accurate moisture measurement method.
Read our article to learn the 7 differences between a pin and pinless moisture meter.
- having an extended range of species settings
- calculating EMC for you
- storing large amounts of measurement data
- on-site calibration
Overall, pinless meters are the way to go. But ultimately, it is up to you to determine the scope of your need for a comprehensive moisture meter for wood enhancements.
In truth, the technology used by both pin and pinless meters haven’t changed significantly over the last two decades.
That’s why the objective tests of Wagner Meter moisture meters, linked below, from years ago remain valid today.
All four of these independent studies, commissioned by Wagner Meters, found that Wagner Meter pinless wood moisture meters were consistently and reliably more accurate in assessing wood moisture content than any of the meters they were tested against.
As Sales Manager for Wagner Meters, Ron has more than 35 years of experience with instrumentation and measurement systems in different industries. In previous positions, he has served as Regional Sales Manager, Product and Projects Manager, and Sales Manager for manufacturers involved in measurement instrumentation.
Last updated on September 14th, 2021