Windsor probe testing is a non-destructive method of compressive strength testing of concrete. It is used to determine the compressive strength by driving a probe into the concrete with a known amount of force. It does not directly measure the compressive strength but measures the penetration resistance of hardened concrete. Therefore, it is applicable only to measure the strength of the in-situ concrete.

Nevertheless, it is among the most commonly used non-destructive methods of on-site concrete testing. The advanced Windsor Probe for concrete can measure a maximum compressive strength of 17,000 PSI.


Many methods used for testing the concrete compressive strength destroy the specimen. Thus, not ideal for on-site testing of existing structures. The Windsor probe test propels a 0.25-inch diameter steel or gold probe into a concrete surface using a drive unit. The probe kite consists of the drive unit, probes, templates, electronic measuring device, measuring caps, gauge plates, and carrying case. The exposed length of the probe gives the measure of the penetration resistance of the concrete. Thus, no destruction occurs.

Accurate measurement

The test agrees with the ASTM guidelines of concrete testing. Unfortunately, many people believe that the ASTM does not recognize this test. But, both The American Society for Testing and Materials (ASTM) and the American Concrete Institute (ACI) recognize Windsor Probe for testing estimated in-situ concrete strength. Thus, it provides accurate results.

However, it is important to understand the test results of the probe test may vary as the factors like deleterious effects such as carbonation, size, and distribution of coarse aggregate, and the location of embedded reinforcing steel often result in inaccurate values.

Fast method

The Windsor probe concrete test was developed in the mid-60s as a joint effort between the New York Port Authority and the Windsor Machine Company. It provides fast results. It is a rapid system for testing the compressive strength of in-situ concrete. The modern Windsor system can measure concrete with a maximum compressive strength of 17,000 PSI.

Why Concrete Insight?

Concrete Insight is a leading concrete testing, scanning, and drilling company. We use the advanced NDT Windsor Probe HP System Z-WP1000 to measure the compressive strength of the in-situ concrete. Our advanced Windsor Probe system allows us to accurately, effectively, and quickly measure the compressive strength of concrete.

Our Windsor Probe Test ASTM can be used for:

  1. Structure analysis
  2. Determination of high-strength concrete strength
  3. Standard concrete strength determination and more

We have more than 25 years of experience in concrete testing. If you need professional Windsor probe testing services, you can contact one of our experts.