Moisture Meter Buying Guide
Moisture occurs naturally in numerous types of materials and industries. Wood, concrete, sheetrock, paper – these materials contain a certain level of moisture that is an integral part of their makeup. However, left unmonitored, that moisture can cause major potential problems, from flooring failures to inventory product losses to professional liability issues.
An accurate moisture meter lets you measure and monitor the materials used in your business or hobby application for their appropriate moisture content (MC) levels. Having the right tool for the job is just as important as understanding the underlying costs of not measuring the material’s MC. Here at Moisture Meter Experts, we want you to find the right tool so that excessive moisture doesn’t catch you unaware. We offer guides, expert reviews, comparisons, resources and products all geared to helping you identify and use the right type of moisture meter for your application. We are here to help because we know moisture meters.
Wood Moisture Meters
The best type of moisture meter for wood will depend somewhat on the type and the dimension of the wood you are working with as well as the application requirements. There are two basic types: pin-style or pinless. What’s the difference?
Pin-style meters usually have a pair of metal probes, or pins, that penetrate below the wood surface to measure the internal MC of the wood. Because they measure by means of a resistance principal that measures the flow of electricity between the two pins, the small area they test is not representative of the whole piece of wood. Several readings along the full width and length of the board, with repeated pin penetrations, are usually recommended for a fuller representation of the total board’s MC. Depth of reading can be controlled by pin penetration or pin size and often, pin-style meters can be attached to external probes for deeper readings if required.
Pinless wood moisture meters, sometimes referred to as non-damaging or non-destructive meters, use a sensor pad with usually a high frequency radio wave signal technology to scan larger areas of the wood for its MC. This technology allows the user to measure the MC of the wood without driving pins into it by sending a three-dimensional signal below the wood surface, measuring deep into the wood. The depth of measurement is usually between 0.25 to 0.75 inches, depending upon the specific model of each manufacturer. These meters can be held in one place or slid rapidly along the entire width and length of the board to obtain MC readings quickly.
Another important consideration when choosing the right meter for your needs is the measurement range of the meter. For certain applications, such as flooring installations, woodworking, and furniture manufacturing, it can be extremely important to have a meter capable of measuring moisture content in wood at the low end of the range, say 6 to 8 percent. Not all meters have this capability. Therefore, depending on your needs, be sure to pay close attention to the effective range of any meter prior to making a purchase.
Concrete Moisture Meters
Moisture meters for concrete include two distinct types of moisture testing: moisture meters or relative humidity (also known as RH or in situ) testing.
Concrete moisture meters are handheld devices that measure a limited range of the concrete’s top surface. They are available in pin-style or pinless (non-damaging) meters and are useful for conducting “relative only” spot checks on the slab for determining where to place additional in situ RH tests.
Concrete moisture meters are not considered accurate enough for documenting relative humidity (RH) conditions as required by groups like ASTM International (American Society for Testing and Materials).
Relative humidity (RH) testing (or in situ testing) determines a concrete slab’s relative humidity (RH) at a specific depth and is proven to best indicate the internal moisture conditions of the slab. This is particularly important when moisture-sensitive finished flooring products are going to be used on top of the slab. Numerous sensors are installed within the concrete slab and allowed to equilibrate before providing RH readings.
ASTM F2170 Standards provide specific requirements and step procedures for using RH testing methods for compliance purposes.
Building Inspection Meters
Building inspection meters provide moisture readings for a variety of building materials. A Building inspection meter is designed to be used for a multitude of materials, including sheetrock, ceramic tile, plaster, linoleum, roofing, and many others. Building inspection meters do not give precise MC percentages but are designed to provide comparative, relative-only MC reading for each material inspected in order to identify problem or potential problem areas in a building or a home. These types of meters are available as pin-style or pinless (non-damaging) meters.
Garden Moisture Meters
Garden meters measure various soil conditions necessary for maintaining healthy growing conditions for your plants, both indoors and outdoors. Ideal water conditions, temperature, soil PH, fertility, sunlight conditions and more can be monitored with a garden or soil moisture meter. Specialized meters can also measure the moisture in stored grains or seeds to prevent fungi, sprouting, insect infestations or other moisture-related problems.
Paper Moisture Meters
For production, shipping and storage, paper moisture meters monitor moisture levels within paper or other fibrous wood-based inventories to ensure stock is not damaged or destroyed by excess moisture conditions. Like wood or building inspection meters, paper moisture meters are also available in pin-style or pinless forms. Some paper moisture meters can also be attached to product-specific external probes for checking the MC in large bales or bundles.
Infrared meters detect radiant heat (energy given off outside of the visible spectrum) through a process more commonly understood as thermal imaging. While they do not typically measure MC, this imagery can help provide a non-invasive way to detect potential moisture problems through temperature variations. Areas of excess moisture will commonly be cooler than other areas, and infrared meters can help building inspectors identify problem areas that need further investigation and measurement with other appropriate moisture meters.