The Anatomy of the Rapid RH 4.0 EX

Concrete moisture content measurement meets the new era with the Wagner Meters Rapid RH in-situ relative humidity test method for measuring concrete slab moisture. Not only does it provide a fast, accurate and easy-to-use job site experience, but the Rapid RH also fully complies with the latest version of the ASTM standard, ASTM F2170-11: “Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using in situ Probes”. The Rapid RH 4.0 EX features the latest Touch-n-Sense™ technology and a new sleeve liner design for dependable concrete moisture content measurement.

The American Society for Testing and Materials (ASTM) established ASTM F2170 in 2002 to acknowledge the methodological integrity of relative humidity moisture testing of concrete slabs. ASTM F2170 was an industry addition to the historic use of anhydrous calcium chloride (CaCl) to measure moisture vapor emissions rate (MVER) in concrete, a method that was being called into question for its accuracy and . The Wagner Meters Rapid RH 4.0 EX affords contractors a scientifically-proven, cost-effective and accurate means of strictly adhering to ASTM F2170-11.

The Method

The Rapid RH from Wagner Meters uses NIST-certified Smart Sensor probes and their Easy Reader digital display to easily and accurately measure concrete moisture content inside test holes drilled into slabs and placed at 40% of the slabs depth. Assessors place the Smart Sensors, with stackable extensions, if necessary, into the test hole. The extensions allow the flexibility to completely line test holes at various depths. This ensures that gradient moisture content inside the test hole itself does not compromise Rapid RH results.

The patented Rapid RH design equilibrates, in most cases, to read moisture content to within three percent of the final reading (defined by ASTM F2170 at 72 hours) only one hour after being placed in the test hole. While full compliance still requires the 72-hour limit, the Rapid RH provides the information crucial for informed business decisions about scheduling, using alternate adhesive or using other flooring choices within one hour.

Once users activate the Rapid RH Easy Reader, it promptly displays the concrete moisture content reading and holds it for five minutes after being removed from the Smart Sensor. This makes quantitative MC assessment easier to record when installers are measuring MC in multiple slab locations.

The Surface Practice

The anhydrous calcium chloride test of moisture vapor emission rate (MVER) has limitations. Put simply, MVER assesses concrete moisture content in the top half-inch of the slab. Calcium chloride is a surface test. Once floor coverings are applied, concrete will equilibrate and evenly distribute moisture from the bottom to the top of the slab. But because moisture will be distributed unequally during the drying process, the final equilibrated rate may fall far outside the flooring application specifications and lead to moisture-related problems.

Concrete moisture meter products are also surface-based assessments. They may measure up to three-quarter-inch of slab depth. However, concrete moisture meter accuracy can be negatively affected by slab density due to variable chemical and aggregate composition. Contractors are advised to never make a final determination on concrete readiness for floor covering based on concrete moisture meter results.

The Advantages of Going Deeper

The Wagner Meters Rapid RH 4.0 EX is the fastest, most cost-effective way to meet ASTM F2170-11: “Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using in situ Probes”.

Because the Wagner Smart Sensors stay in the test hole, there is never a need for re-equilibration time. Installers can leap-frog, measuring several slab locations in succession, to enhance cost savings while ensuring thorough slab moisture content measurement. This is especially valuable for areas which can hold more moisture, such as near concrete pillars, in corners or below grade.

The Rapid RH 4.0 EX starter kit is an all-in-one carrying case with all necessary materials, including five Smart Sensors. For repeat users, Wagner Meters offers Easy Reader and Smart Sensor replacement packs. Buyers can save even more on bulk packaging purchases.

The Wagner Meters Rapid RH 4.0 EX sets the industry standard for dependable, cost-effective measurement of concrete moisture content.

Article by Jason Spangler

Jason has 17 years experience in sales and sales management in a spectrum of industries and has successfully launched a variety of products to the market, including the original Rapid RH concrete moisture tests. He currently works with Wagner Meters as their Rapid RH product sales manager.