With the chuck on both the micrometer and pin driver, flat surfaces can be easily and accurately measured. Simply make sure the chuck rests against the surface and pull the trigger. After the pin has penetrated the surface, clean the hole with the provided lower, measure depth of penetration and compare to the previously prepared chart for the compressive strength of your material. Charts for typical mortar and concrete is provided.

The recommended practice is to take seven readings discarding the two readings farthest from the mean. By doing this the possibilities of striking a flaw or near surface piece of hard aggregate and using the resulting penetration to calculate strength are sufficiently reduced. Grinding the surface flat before testing pro- duces more consistent results.

With the chuck removed the pin driver is capable of accurately testing mortar joints. By inserting the V-barrel into the mortar joint the pin will directly penetrate at the center of the joint. By following a similar procedures as above the compressive strength of the mortar joint can be accurately and safely tested. A similar v-shape for the micrometer facilitates measurement.

Windsor Pin™ SYSTEM OPERATING PRINCIPLE
A spring-loaded device drives a steel pin into the surface of concrete or mortar and the depth of penetration is measured. Since the depth of penetration is inversely proportional to compressive strength, this system provides a fast and efficient way of determining the in situ strength of material.

The spring is loaded by tightening the loading nut until the trigger mechanism latch closes to hold the spring in place. The stored potential energy is 91 lbs. in (108 NM). With the spring loaded, it is compressed to a distance of 0.8 inches. Thus, once the trigger is pulled there is enough force to test the compressive strength of concrete to a maximum of 5300 PSI (36.9 MPa).