The Rapid RH’s design incorporates an accurate RH/temp sensor designed into every Smart Sensor Insert. This technology allows you to get a first set of readings faster than other methods, along with additional sets of readings. Complying with ASTM F 2170, the Rapid RH is a critical tool for anyone working with vapor retarding decorative concrete surfaces. Rapid RH fits beneath the surface of the concrete, does not impact ongoing construction, and requires no ongoing calibration. Wagner Electronics. 800-634-9961.