The Fietz Concrete Tester grew out of a need to measure depth of fire damage to a reinforced concrete frame structure. It was not possible to take standard core samples and surface distress prevented use of some common NDT test methods that required considerable time, dust, noise, waste and expense needed to prepare the concrete to be tested.

Technical Consultants, Inc. (TCI) was retained to determine the extent of strength loss in the concrete exposed to the fire. TCI used a test took that required only a small entry hole into the concrete. Test results were compared to similar tests conducted on concrete known to be out of the fire zone.

The test method Mr.Fietz used was first developed many years ago for measuring the strength of metallic materials. That is, to measure the resistance to penetration of a material by a probe and relate the depth of penetration to the force required to produce it. The relationship has been accepted as a reliable indictor of the material strength.

Recent additional development of this concept produced the Fietz Concrete Tester, U.S. Patent 8528387