How To Use a Moisture Meter for Measuring Moisture Content
There are many different occasions in the home where a moisture meter can provide valuable data. Moisture meters can assess wood, concrete, paper, and drywall for water and dampness.
Moisture meters, also known as moisture detectors, can check out the water levels in walls that may have been exposed to a slow leak. These meters also evaluate drywalls if you can smell mustiness and suspect hidden dampness and even survey firewood to make sure it is dry enough to burn.
Moisture meters are generally small electronic devices that are pretty straightforward to use and not expensive to buy.
There are a couple of different types, so it is worth doing your research to ensure you end up with the right one.
Buying The Right Moisture Meter
Although moisture meters theoretically can test various materials, think about the primary type of surface you will be using the meter on as many are precisely calibrated.
Pin meters will measure the moisture when the pin is inserted into the material. Depending upon what you want to test, a pin meter may not be the right choice for you.
Selecting a meter with longer measuring pins will make it easier to penetrate deeper into certain materials.
You will need a meter with Teflon-insulated measuring pins to measure moisture gradients. Moisture gradients are the variation between the moisture levels on the surface of a material compared to the inner portion.
Some meters have interchangeable pins and so are suitable for a variety of different materials.
Read more: How to detect moisture in walls
Calibrate The Moisture Meter
This is an essential step; otherwise, the readings will not be accurate. The process of calibration depends upon the type of meter being used.
Some meters have in-built calibration or calibration kits that are purpose-made and designed to be used alongside a meter.
A Moisture Content Standard offers a quick and easy way to verify the accuracy of a meter that doesn’t have a built-in calibration facility.
A Moisture Content Standard provides several checkpoints to give the user total confidence that the readings provided by the meter are accurate.
Some meters come pre-calibrated, which may be easier if you only intend to sample one material.
If your meter seems out of calibration, always check or renew the batteries as a starting point.
Take The Reading
The exact way to use the meter will depend on your type.
Once calibrated, a pinned meter should be positioned, so the pins are perpendicular to the substrate surface. The pins are then pushed into the surface as far as possible to take the reading.
Make sure both the meter and the surface you are testing are completely dry before taking a reading. Remove any visible water or condensation.
If you are using a pinless meter, it is important to apply the correct amount of pressure to it as it connects with the material’s surface via the sensor pads.
Usually, the manual that comes with the meter will detail the right pressure level to apply.
A pinned meter will require repeated usage across different areas of the tested material to provide an accurate assessment.
A pinless moisture meter simply requires the testing surface to be pressed against the wall or material. This can be repeated in different areas according to preference.
Some moisture meters have interchangeable tips that can be useful to test various materials.
Different walls have different requirements; always check which tip is appropriate for the material you are working with.
Do Not Use Old Holes
If you check the moisture levels in wood or drywall, do not use old holes used before, though this may minimize damage.
Old holes have leftover moisture and can lead to inflated readings, affecting the readings’ accuracy.
Keep Fresh Batteries To Hand
Some meters provide inaccurate readings when the capacity of the batteries lowers towards the end of their lifecycle. Always check battery strength as part of your pre-checks before using the meter.
Look for rechargeable meters if you know you tend to lose batteries in your drawers!
How Does A Moisture Meter Work?
It depends on what type of moisture meter you are using.
A conductive meter uses an electrical circuit between two and four-pin probes either on the wall’s surface or actually embedded in the wall’s structure. The circuit is completed through the meter.
A conductive meter works by measuring the electrical resistance, which is affected by the moisture content in the wall.
A capacitance meter either has conductive plates on the meter itself or a separate head with conducting concentric rings, which are placed on the surface of the wall.
The meter measures the sensor’s fringe capacitance, reflecting the moisture level in the wall.
The way the results are displayed depends on the type of meter. Capacitance meters use an audible tone or high-frequency signal to indicate changes in moisture levels.
Other moisture meters provide a digital readout of the results.
What is Bad Moisture Reading?
Bad moisture reading indicates that there is dampness or water present outside the accepted parameters for the material you are testing.
Moisture levels will also vary depending on ambient humidity and surrounding temperature levels.
Getting the right balance of humidity in the home is essential to protect against dampness and mold associated with too much moisture. Conversely, ambient air which is too dry can cause other health issues.
It is essential to know the accepted percentages for what you are testing as this can signpost whether remediation is possible or if all-out replacement is the only option.
For most materials, the range is 5% to 40%, and generally, anything between 5% and 12% is considered a low reading. 12% to 17% is deemed moderate, and even a measure as high as 17% can be remediated. Anything above 17% is considered high.
Bear in mind that moisture meters can give misleading results. Commonly, this is because they are either not being used correctly or have not been calibrated properly for the material they are testing.
If the meter is being used on a wall containing salts, an artificially high reading can be produced because salts are hygroscopic, naturally attracting water.
How Many Types Of Moisture Meters Are There?
There are two types of moisture meters: conductive and capacitance meters. However, most moisture meters are simply pinned or pinless for the average homeowner.
Pinless meters don’t leave any marks and tend to be more desirable and expensive! A sensor pad transmits an electromagnetic signal, and the meter evaluates the variation in wave movement reading to work out the amount of water present.
Pin meters feature between two and four steel probes inserted into the material to measure the moisture levels. The reading can only detect moisture as far as the pin is inserted into the material; depending on the wall’s surface you are testing, that may not be very far. The electrical current goes from one pin to the other, and the meter measures the resistance.
Pin meters are good on uneven surfaces and do not require a flat surface to read accurately. Pin meters can also detect moisture gradients and offer a greater depth reading span than pinless meters. However, if the pins cannot penetrate the surface, the meter won’t work.
Pin-type meters only measure water content between the pins and require repeated readings to establish proper moisture levels across the wall or surface.
Moisture meters are a boon for householders keen to keep their properties in good order and free from dampness and mold. These meters receive mixed press, but a good brand correctly calibrated and used according to the manufacturer’s instructions can yield accurate results.
Whether you are looking for general advice on an appropriate household regimen, specific expert guidance after damage caused by flood, storm, or fire, or just want to know how to use a moisture meter, All Dry USA is here to help.
Trusted in this field for more than a decade, we will always rescue and remediate where possible rather than incur unnecessary replacement and added expense.
Send us an email or call today for a quote!