To obtain a quantitative determination of internal relative humidity in concrete slabs for field or laboratory tests. Please verify the products being used have a published RH reading prior to using this method.
Results are expressed in percent and whether or not the concrete is acceptable to receive floor coverings, coatings, cement toppings or specific vapor control sealers. Excessive results may cause deterioration of products, loss of adhesion and possible microbial growth.
Developed in Europe, the Relative Humidity In-Situ probe test was adopted by ASTM in 2002.
ASTM F2170 requires the test measurement when concrete floors are at service temperature and interior room space above the floor slab to be at service temperature and service relative humidity for at least 48 hours. Concrete results may differ as building conditions change. Do not expose probes to high pH or water during testing period.
Condition and control temperature and humidity for 48 hours prior to and during testing.
Installed at below-grade, on-grade and above-grade (suspended) slabs at a rate of three (3) tests for areas up to 1,000 square feet and one (1) more test for each additional 1,000 square feet of floor area.
Select a test site away from windows, protected from direct sunlight and 4 feet from exterior walls. Once a location is selected, proceed with the following:
• Drill a 2 inch depth hole using an SDS hammer drill and 5/8” bit
• Blow the hole free of debris using compressed air and a vacuum
• Insert the pre-measured sleeve in the hole and secure
• Insert the RH probe, install sleeve cap and allow to remain for 72 hrs.
• 4 - 5 inch concrete thicknesses, use pre-measured sleeves. These sleeves are pre-cut and used for slab on grade with a vapor barrier directly below the slab and slab on deck concrete drying from the top down.
• Contact our technical services department for other applications.
Quick readings may be reached after the holes to reach equilibrium for 24 hours. Remove the sleeve cap and connect the meter cable to the probe. Allow the probes to re-acclimate for 30 minutes.
If following ASTM F2170 protocol, all freshly drilled holes need to reach equilibrium for 72 hours. Remove the sleeve cap and connect the meter cable to the probe. Allow the probes to re-acclimate for 30 minutes.
Mark all test numbers and locations directly on the concrete surface. When readings are required at a later date, apply the sleeve cap and return to test as need.
The RH meter displays temperature and percentage of relative humidity. To verify relative humidity, press the read button on the meter and when the (:) sign appears on the screen, note the RH%. When finished press the arrow up or down button and the temperature is indicated in degrees F when (+) appears on the screen.
Most manufacturers require a reading of less than 75% RH. If products do not list an acceptable RH level, ASTM F710 offers a result of 75% (or less) as acceptable for resilient flooring systems. Readings above 75% fail this test. Please consult flooring manufactures technical data for details.
RH probes require re-calibrate annually or more frequently if exposed to environmental conditions that affect measurement accuracy. Pleas contact our technical department for calibration procedures.
• SDS hammer drill - minimum 5/8 inch
• 5/8 inch SDS drill bit
• Compressed air
• Concrete vacuum
• Electrical cords