Moisture Mapping is a key feature to any concrete moisture testing program. It involves methodical measurements of moisture levels within a concrete slab to create a moisture map that helps identify potential problem areas.
### What is the Best Measure of Moisture?
The most preferred and direct way of measuring slab moisture levels is to obtain a concrete sample and test it in a laboratory using either the gravimetric method or the calcium carbide (Speedy) method. However, these methods can be expensive and time-consuming. Therefore, in-situ methods are frequently used as alternatives:
* **Relative Humidity (RH)** – RH sensors are placed inside the concrete slab and measure the relative humidity of the air within the pores of the concrete.
* **Electrical Resistance** – Electrical resistance meters measure the electrical resistance of the concrete slab. The resistance is inversely proportional to the moisture content of the concrete.
* **Moisture in Concrete Vapor Emission (MVE)** – A non-destructive method that measures moisture vapor emissions from the surface of the concrete slab using a calcium chloride test.