Abstract: A test kit for measuring vapor emission from a concrete floor or other planar surface prior to installing a flooring material includes a relatively rigid dome-shaped cover having an outer bottom rim for seating with the planar surface to be tested when the cover is placed on the surface over an uncovered container of moisture absorptive material such as calcium chloride. The test kit further includes a weight ring that is removably placed onto a shoulder portion of the cover located at the cover's outer bottom rim. Placement of the weight ring on the dome-shaped cover during tests acts to hold the outer bottom rim of the cover in seating contact with the test surface. The test kit is easy to use and provides for reusable components. It can also be used without leaving a residue on the test surface.