Top 5 Differences Between Pin and Pinless Moisture Meters

When looking for accurate wood moisture measurements, you’ll immediately run into two different styles of moisture meters: pin and pinless. Which is the better addition to your tool belt? There are some basic differences that you should understand before you buy.

Pin Moisture Meters

Pin moisture meters determine a wood’s moisture content by measuring the resistance encountered by an electrical current running between a couple of small pins that are inserted into the wood.

This method works because water conducts electricity and wood doesn’t. The drier the wood, the more resistance to the electrical current.

Because pin moisture meters are sensitive to variations in wood temperature, a high-quality meter should come with correction charts or have a method to adjust the readings for wood temperature.

Pin moisture meters are also sensitive to the chemical makeup of the wood. Since this varies from species to species, quality pin moisture meters will ask you to input the type of wood or provide for species adjustment before taking a reading.

Pinless Moisture Meters

Pinless moisture meters measure a wood’s moisture level using an electromagnetic signal. Since they don’t poke holes in the wood they’re good for measuring the moisture level in fine furniture and expensive hardwood floors.

Pinless wood moisture meters are sensitive to variations in wood density (also referred to as specific gravity). Because different types of wood have different densities, users will need to make sure the meter is set to the correct specific gravity setting before measuring.

1. Pin vs. Pinless Moisture Meter

How does a pinless moisture meter work?

Pinless moisture meters work via an electromagnetic sensor pad that comes into contact with the wood surface but does not physically break or damage the surface to take a reading. Pinless moisture meters can measure moisture content from the surface down to .25″ or, for deep measurements, from .75″ to 1.5″.

How does a pin moisture meter work?

Pin-type moisture meters have two metal probes that must physically penetrate the wood’s surface in order to take a moisture reading. When the meter is turned on an electrical current flows from pin to pin and measures the resistance.

Pin-type meters take advantage of the fact that water (with salts and impurities) conducts electricity and wood doesn’t. This makes it possible to determine the moisture content of wood via measuring the resistance to an electrical current. Drier wood will show more electrical resistance.

Broken or bent pins are one drawback of pin moisture meters. This is because the pressure used to push the probes into the wood can cause them to bend or break. (Some woods are harder than others and with dense wood, it can be difficult to insert the pins. Broken and bent pins are more common with harder species of wood.) Of course, if the pins on your moisture meter break or bend, they’ll need to be replaced. This is not only inconvenient but, if your pins break on a regular basis, it can be expensive as well.

2. Electromagnetic Sensor Pad vs. Pins

What is a pinless meterThe difference between a pin and a pinless moisture meter rests in the underlying technology.

Pin meters measure the resistance to an electrical current flowing between the two pin tips. Pin meter accuracy is affected by the chemical composition of wood, which varies from species to species.

Whatever type of wood moisture meter you’re using — pin or pinless — you’ll need to take multiple readings to get an overview of the wood’s moisture content. However, this is much harder to do when you’re using a pin meter because pin meters only measure the moisture content between the two pins and nowhere else. In other words, you’ll need to take far more measurements to approximate what a pinless meter can easily do in one quick scan. Remember, each reading with a pin meter requires poking two new holes in the wood.

In contrast, pinless moisture meters use a large sensor pad and emit electromagnetic signals to measure the moisture content of the wood. This allows you to quickly and accurately scan large areas and get instant moisture meter readings. Pinless meters allow you to scan many board feet in just seconds without the time-consuming effort of driving pins into the wood.

3. Holes vs. No Holes

As we’ve already mentioned, a pin meter needs to penetrate the wood’s surface to measure the moisture content. Therefore, each moisture content reading will make a pair of pinholes in the wood, and as we noted above, you’ll need more than one reading to get an overall view of the wood’s moisture content. For 2x4s or firewood, this probably won’t be a problem. However, if you’re measuring the moisture content of expensive wood flooring, furniture, cabinets, or other fine woodworking projects, these pinholes will become a series of blemishes on the wood’s surface. In contrast, pinless meters with their flat, smooth sensor pad don’t cause any damage to the wood.

Shop Wood Moisture Meters

4. Fixed-Depth Readings vs. Variable-Depth Readings

Pinless moisture meters generally operate at two standard reading depths: ¼” below the wood surface, and 3⁄4” below the surface. For most woodworking projects, like wood flooring or cabinets, or for building materials, these depths provide the necessary moisture content readings.

When using a pinless moisture meter you’ll need to be careful about how much pressure you apply. If you apply too little pressure there might be a slight gap under the device that will affect the accuracy of the reading. In fact, just the position of your hand can affect the accuracy of some less expensive moisture meters.

With pin moisture meters the moisture content reading is taken at the depth of the pins. That means if the pins aren’t inserted properly, the reading may not be accurate.

As we mentioned above, the pins on pin moisture meters can, at times, be difficult to push into the wood. While this isn’t usually a problem with softer woods, it can become a real issue with hardwood species. This is often how pins end up bent or broken. (Longer pins are more likely to break during use.) When this happens, if you don’t have replacement pins on hand, you’re out of luck. Your meter is unusable.

5. Calibration

NIST Traceable On-Demand Calibrator Platform

On-Demand Calibrator for Orion Moisture Meters

All moisture meters for wood need to be properly calibrated in order to provide accurate moisture measurements. High-quality pin and pinless meters allow you to verify factory calibration using a calibration reference device. If you find that your meter is out of calibration, you send it back to the manufacturer for recalibration.

Wagner’s Orion line of moisture meters goes a huge step further by providing you with an On-Demand Calibrator device that allows you to actually recalibrate your own meter. In other words, you don’t need to send your meter back to us for recalibration.

The accuracy of both pin and pinless moisture meters depends on using them correctly according to the manufacturer’s instructions.. It’s also a good idea to make sure a low battery isn’t causing any inaccurate readings. Wagner meters include a low battery indicator.

Moisture Meter Settings

In order to correctly use any meter, either pin or pinless, you’ll need a wood species adjustment table or, for programmable meters, the ability to enter the correct species setting.

Pin Settings

Pin wood moisture meters are sensitive to temperature and, because of this, all quality pin meters will come with a temperature correction chart.

Pin meters are also sensitive to a wood’s chemical makeup which differs according to species. Therefore, quality pin meters will always ask you what type of wood you’re measuring.

Pinless Settings

Pinless moisture meters are sensitive to a wood’s specific gravity (i.e., density). Because this varies according to species, you’ll need to set the meter to the proper density setting before you take a measurement.

Speed

Pinless wood moisture meters are faster because they can scan many points in a quick swipe. If you used a pin meter, you would need to take several readings to cover the same size area. This is because a pin meter only measures the moisture between the two pins. Remember, each time you take a reading using a pin meter you leave behind two small pinholes in the wood.

Surface Moisture

Pin meters that use 1 1/4” length or longer pins with insulated shafts aren’t generally affected by surface moisture on the wood. Pin meters using only short pins without insulated shafts are far more prone to problems with surface moisture.

Surface moisture can also be a problem for pinless meters. For example, when wood has a small amount of condensation on it, a pinless meter might detect a moisture measurement range from 10-20% higher.

Wagner’s IntelliSense™ technology greatly reduces this problem. IntelliSense™ allows Wagner moisture meters to minimize the effect of slight amounts of moisture on the surface of the wood. In other words, Wagner meters read the moisture in the wood, not on the wood as other moisture meters do.

Relative Measurement Mode

Relative measurement mode is used for obtaining relative, rather than absolute, measurements. It’s typically used for non-solid wood applications. You might use it to get an idea about how wet or dry a piece of drywall is, for example.

With relative measurement mode, the meter doesn’t tell you the actual percentage of moisture content in the wood, but rather provides relative measurements of a non-solid wood building material by measuring a known dry area of the material to establish a baseline, and then further scanning the material to determine if there are areas of the material that measure significantly higher than the dry baseline measurement. For example, this is useful when you’re trying to find a water leak. Locating wet spots can greatly help in determining where a building may have a leak.

What Is a Moisture Meter Used For?

Wood moisture meters — both pin and pinless — are used for determining the moisture content of the wood. This is important because wood shrinks or expands as it loses or absorbs water moisture from the environment. Woodworkers, hardwood flooring installers, cabinet makers, etc. don’t want to put down expensive flooring or install a custom cabinet only to see it deform later when the relative humidity of the environment changes. They avoid this problem by using a moisture meter to make sure the wood they’re working with has been dried to the correct moisture content before they start working with it and that it remains at that moisture content during the construction process. For non-solid wood materials, they can also provide valuable comparative measurements.

Shop Wood Moisture Meters

The Accuracy of Wagner Pinless Moisture Meters

Wagner pinless moisture meters have been proven accurate in a number of studies…

Wagner pinless meters are also mostly unaffected by the ambient temperature.

A study conducted in 2000 by the Building Research Establishment’s Centre for Timber Technology showed that the readings produced by Wagner’s handheld meters were more consistent than readings produced by pin-type resistance meters.

In another study by the University of Florence and the Wood Research Institute found that, in a greater percentage of cases, the values obtained using Wagner pinless meters were closer to the values obtained using the oven-dry method than were the values obtained via pin moisture meters. (The oven-dry method is considered the gold standard when it comes to measuring the moisture content of the wood.)

We’re proud of our moisture meters. In fact, our Orion® 950 Smart Pinless Wood Moisture Meter just won the Visionary Award at the Association of Woodworking and Furnishings Suppliers (AWFS) 2019 Fair in Las Vegas, Nevada.

For more information about Wagner pinless wood moisture meters see our handy Orion® Moisture Meter Comparison Matrix.

25 Comments

  1. Dick McCarthy says:

    I recently purchased a Masterdraft pinless moisture meter model 057-4572-0 from Canadian Tire. I bought it to measure the moisture content of my firewood. I am not certain if Big Leaf Maple (Vancouver Island) is considered softwood, hardwood, or soft hardwood. More importantly I am not certain if this moisture meter can measure the moisture in firewood. Perhaps it is only designed for kiln dried dimensional lumber. I have been told that Wagner makes, or is the dealer for Mastercraft moisture meters so I hope you can answer my questions for me. When I checked Wagner on the internet, your name came up and this is the e-mail I was given. Can you help me. I certainly would appreciate it.
    Thanks kindly,
    Dick McCarthy

    • Ron Smith says:

      Thanks for writing, Dick. Wagner Meters does not manufacture Mastercraft moisture meters nor do we offer any meters that are designed for use with firewood. I’m sorry for any confusion. I’d suggest returning to the store you purchased the meter from or contacting the manufacturer directly for assistance.

  2. Jeremy says:

    Hello,
    If the wood has a surface coating can that affect the reading of the meter? For example painted wood or a lacquer coating. If yes then does that mean one should use a meter with pins?
    Thanks,
    Jeremy

    • Jason Spangler says:

      Jeremy:

      Thanks for the question. No, neither of the coatings you suggested here would have any impact on the readings obtained by our meters unless the coating contained aluminum oxide or any other metallic. In this case, there would potentially be variances in readings.

      Jason

  3. noda droper says:

    Question – We are preparing to re-paint wood clapboard house and want to make sure that the underlying moisture of wood is appropriate before painting.

    Pinless or 2-Pin Model: We would prefer a Pinless meter (fewer holes left in wood, more readings). Can we use a pinless wood moisture meter to assess readiness for paint, assuming that we are testing not raw wood, but wood that may have already been painted and scrapped, or primed?

    • Tony Morgan says:

      Yes, a pinless can be used to measure the painted wood on your house as long as you know what the wood species is for the clapboards. Paint should not significantly affect the moisture readings of a pinless meter. The only obstacle could be if there are too many layers of built-up paint over the underlying wood or there is metal content in the paint, lead-based paint is an example of this.

  4. Tim says:

    We’ve treated some roof timber with a preservative. Will this affect the readings of either type of meter?

    • Tony Morgan says:

      Tim,

      It depends on the type of treatment you used. If the treatment has no metal content in it, such as copper, there should not be a significant change in your readings. If the preservative is metal-based, there may be a rise of 4% or more in your readings. The best way to check the effects would be to take some readings of a non-treated section of the roof timber, treat the timber and, after a sufficient drying period, recheck the same section for any change in the readings. This would give you a baseline and correction factor for the treated timbers.

      Thanks,

      Tony

  5. Ramiro Rivera says:

    Would the pinless moisture meter be able to penetrate through stucco on houses? Typically stucco is 3/4″ to 1″ thick and contains lathe. I would be interested in figuring the moisture of the sheathing (typically plywood) behind the stucco/lathe AND then use a pin meter for specifics.

    • Tony Morgan says:

      Hello Ramiro,

      The BI2200 is designed to take relative readings for many products, including stucco, but there is a problem with your intended application. The problem with stucco is that it is normally troweled onto a wire mesh, and this mesh would most likely interfere with any readings you would be trying to get from the lathe underneath. The metal of the mesh will disrupt the electromagnetic signals of a Wagner moisture meter and the result would be inaccurate readings.

  6. vijay kumar Srivastava says:

    requirements of pin type moisture meter rate and catalouge

  7. John Schenk says:

    I recently have begun replacing my linoleum floor with hardwood, I noticed by my back wall there has been water coming in from an exterior wall and settling on the subfloor. I need to track where (in the wall) the water is originating from. Can you suggest a pinless meter for tracking moister behind 5/8″ – 3/4″ drywall?
    Thanks,
    John

    • Eric Wagner says:

      John – the Wagner Meters BI2200 is often used to track down moisture issues in walls. Hopefully it will help you too!

  8. Anton says:

    I have been using Wagner MMC220 and L609 for more than 3 years. They are really good stuffs.

    1. Does Wagner provide moisture meter with hammer electrode (pin)?

    2. I have Radiata Pine with 38mm (1.5″) thick.
    A. Use Wagner MMC220. The number in shown in screen would be moisture at which depth of wood? Would it be 19mm (3/4″”) below surface?
    B. Use hammer electrode. Penetrate the pin into wood at 19mm (3/4″). The reading on screen will show the moisture in which depth below wood surface?

    3. How to use MMC220 for tropical timer specie (like Jelutung) which is not available in your wood specie list?

    Many thanks for your help.

    Regards, Anton

    • Tony Morgan says:

      Anton,

      Wagner Meters does not manufacture any meter with pins. Please refer to the following link to an article from the Wagner website explaining how the pinless technology works:
      https://www.wagnermeters.com/electromagnetic-wave-technology/

      The Wagner MMC220 has a scanning depth of ¾” and L609 scans to a depth of ½”. What this means is that the meter takes a reading the length and width of the sensor plate down to the depth appropriate to the meter and gives a moisture content reading of the average of the whole area. For a board with a thickness over the rated depth for the meter, it is recommended that readings are taken from both sides of the board.

      If you are unable to find the specific gravity (SG) in the Species Settings manual, click here. Or you can contact a Wagner wood expert at 800-634-9961 during regular business hours (7:30-4:00 PST) to get an SG setting that is not in the manual.

      Jelutung (Dyera costulata) has a specific gravity (SG) of 0.46

  9. Anton says:

    Tony,

    Thanks for helpful info. In other say, what shown on screen of MMC220 is average of moisture content in the whole wood under censor pad (Length & Width) as deep as 3/4″. Is my understanding correct?

    Understood on recommendation to measure both sides of wood if the wood thickness is over 3/4″ for MMC220.

    Regards,
    Anton

    • Tony Morgan says:

      Yes, the reading on the MMC220 is the average moisture content for the material to a depth of ¾”.

      Thanks,

      Tony

  10. Wayne says:

    I have been using the MMC220 for some time now but sometimes I need a meter that reads a depth of 1/4″. Does Wagner have a meter that will do the job?

    • Tony Morgan says:

      Wayne,

      Thank you for being a long time Wagner user. No, Wagner does not manufacture a meter that reads at a depth of 1/4″.

  11. It is amazing and wonderful to visit your blog. Thank you for writing the difference between pin and pinless moisture meters. I’m looking to read more blogs from you.

  12. Harshad Raveshia says:

    We are one of the largest manufacturer of Wooden Pencils in India. Comparing to other Wood Working Industries, Moisture in Pencil Wood play much more important role in Pencil Production.

    The only way is to determine correct Moisture is Good Instrument which can give correct reading.

    Our Basic Sizes are as under:

    For Pencil Slat Cutting:

    Height 80 MM X Width 160 to 300 MM X Length 185 to 2000 MM Block of Wood for Frames Saw Machine. Desired Moisture Content: 15% Maximum.

    For Pencil Production Line:

    Ready to use Treated and Seasoned Pencil Slat for Grooving having 5.25 mm Thickness X 75 mm width X 185 mm Length. Desired Moisture Content: 7%

    Ready to Shape Sandwich (Pencil Lead bonded between 2 Grooved Slats with Adhesive) having 9 mm Thickness X 72 mm width X 180 mm Length. Desired Moisture Content: 7%

    What kind of Pinless Moisture Meter you suggest?

  13. Anas Malik says:

    Please tell me about your Moisture Meter why are pinless moisture meter (density/Frequency/accuracy/reading) 28 and

    pin moisture. meter (density/Frequency/accuracy/
    reading) 58 WHY ?.

  14. PCTE says:

    This blog post would help people understand the difference between pin and pinless moisture meters before they buy. Keep up the excellent work!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.