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Windsor® Probe Test System
Most Advanced System For Compressive Strength Testing
of Standard and High Performance Concrete

Windsor® Probe System
Windsor Probe® System

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For orders outside the United States and Canada please contact us and we will be happy to get you a complete quote.
If you are not sure on what item to buy, please see our Purchasing Notes below or contact us and we'll be glad to assist you on your order.

We also offer an "Add extended warranty" option to your purchased instrument! Just add it to your cart.
Instruction manuals for this equipment can be found here:
Windsor® Probe HP Manual
Windsor® Probe Basic Manual

Preparing the Windsor® Probe Driver
Firing the Windsor® Probe
Using the Windsor® Probe Measuring Unit
Item# Item Name   Qty Add
Z-WP-1000 Windsor® HP Probe System
(Price Does Not include Probes)
Z-WP-534 Windsor® Probe Manual System
Z-WP-534-EXT Windsor® Probe Manual System Extended Warranty
Z-WP-1000-Ext Windsor® Probe System Extended Warranty
Check the items you wish to purchase, then click

Product Description:

Purchasing Notes:

Probe contain a powder charge as such they are considered a hazardous good for shipment purposes. Please contact us for ordering outside the United States so we can review the proper shipping procedures with you.

We would also recommend the R-HR-8000 Mini R-Meter for locating safe areas to test.

Product Information:

For in-place strength testing of normal and high-performance concrete.


  • Form Removal

  • Structural Analysis

  • Light-weight concrete strength determination

  • Standard concrete strength determination

  • High-strength concrete strength determination

  • High-precision determination

Measures the compressive strength of concrete accurately and effectively, on-site in the field.

The Windsor® HP Probe system rapidly and accurately determines the concrete compressive strength of a structure by driving a probe into the concrete with a known amount of force. Improved and enhanced over thirty years, this modern system is capable of measuring concrete with a maximum compressive strength of 17,000 PSI (110MPA). It has been ruggedized for use in the construction environment, yet refined to provide the user with a simpler system to operate. An electronic measuring unit has been added to help ensure proper test results which can be recorded for later review or uploading to a personal computer.

Two probe styles are available: one for lightweight, low density concrete with air filled aggregate and the other probe for more standard mix designs. Also, two standard power settings facilitate testing fresh concrete as well as mature mixes.

The Windsor® Probe test has been approved by federal, state and municipal agencies as well as a number of foreign countries in Asia and Europe. It conforms to the following tests, specifications and practices:

    ASTM C-803 Standard Test Method for Penetration Resistance of Hardened Concrete

    ACI 228.1R-03: In-Place Methods to Estimate Concrete Strength

    ACI 228.2R-98: Nondestructive Test Methods for Evaluation of Concrete in Structures

    ANSI A.10-3

    BS 1881 Part 207 Testing Concrete

    TS 13537 Test Method for The Determination of Penetration Resistance of Hardened Concrete

Features & Benefits:

  • New electronic measuring system enhances accuracy and efficiency

  • Measurement to 17000 PSI (110 MPa)

  • Memory for data storage and uploading to PC

  • Safe: no accidental discharge and no recoil

  • Fast and economical use

  • Determines the developing strength of concrete; improves safety, ensures quality

  • Larger Light Weight Actuating Template Protects the User from Debris

  • Monitors the strength for rehabilitation as concrete ages

  • Conforms to ASTM C-803 and other official tests

User Friendly:

The Windsor® HP System does not require great skill to use, plus consistent results can be obtained by construction site supervisory staff or field technicians. In fact, among its users are: contractors, engineers, architects, testing laboratories, ready mix concrete producers, owners, managers and government authorities. This system has widespread use in testing concrete in-situ; on conventionally placed, sprayed or precast concrete; on horizontal or vertical slabs; on floors or overhead; on fresh or mature concrete.

The system is safe to use. The driver cannot be discharged unless it is fully depressed with some force against the actuating template which rests against the surface being examined.


The Windsor® HP Probe System is designed to evaluate the compressive strength of concrete in place. It is non-destructive and can be used with equal effectiveness on fresh and mature concrete. Equally accurate results are obtained on horizontal or vertical surfaces provided that the probe is perpendicular or at right angles to the test surface.

A hardened steel alloy probe is propelled at high speed by an exactly measured explosive charge into the concrete and its penetration measured. Each power load is guaranteed to have an energy level to give an exit muzzle velocity tolerance within ±3%. The compressive strength of the concrete is directly related to the resistance to penetration of the crushed aggregate and cement matrix: this is determined by the distance required to absorb the specific amount of kinetic energy of the probe. The compressive strength of the concrete is empirically related to the penetration that varies with the hardness of the aggregate. This relationship is recognized by determining the Moh's scale of hardness of the aggregate and applying a correction factor to the penetration.

The combined contributions of both the aggregate and the cement paste to concrete strength are examined by the test. The accuracy of the inferred strengths has been examined in many independent tests and trials. The Windsor® HP results correlate well with the concrete strength determinations obtained by conventional means.

For most accurate test results ASTM recommend so that a correlation be developed for the particular mix design being tested. Exact duplication of cylinder test results should not be expected. The probes measure the strength of the actual concrete in a structure rather than that of a sample compacted and cured under strict and somewhat artificial conditions which do not necessarily represent those of the structure itself.


There are two power settings available, low and standard power. The low power is used where concrete strength is less than 3000 psi (19.4 MPa). The newly designed silver probes can be used for high performance concrete with strength up to 17000 psi (110 MPa). The probes are made of a high strength alloy, specially heat treated and annealed to achieve a hardness of Rockwell C 48. Special machining of each probe eliminates stress concentrations.

The gold probe has a 56% greater cross-sectional area than the silver; it is recommended for light weight concrete - less than 125 lbs/cu. ft. (2003 Kg/M3) in density. The silver probe is used with concrete having a density greater than 125 lbs/cu. ft. (2003 Kg/M3). (Note: The Harm Code for Silver or Gold Probes is - # 9306.36.4160)

Purchase Probes for The Windsor® High Performance Probe™ System

(in Sets of 3 or Case of 75 & in Gold or Silver)


A. Actuating

Load the driver with a power load and probe suited for the type of concrete being examined. Place the driver firmly on the actuating template and fire. The locating template is then used to locate the probes at the corners of a fixed triangle. Normally, three measurements are required for consistent and statistically reliable results.

Video: Preparing the Windsor® Probe Driver

Video: Firing the Windsor® Probe

B. Measuring

The electronic measuring device is menu driven and programmed for selection according to the following parameters.

  • Aggregate hardness

  • Light weight, normal, or HP concrete

  • American or Metric units

The three individual tests are automatically averaged and displayed on the LCD in accordance with the ASTM procedure. This data together with time and date of the test are stored in the memory for subsequent uploading to a PC. An extractor is supplied to facilitate probe removal after the test.

Video: Using the Windsor® Probe Measuring Unit

The Standard Windsor Probe ® System includes a depth gauge and 'Strength Chart"ť for determining the concrete strength. This is an economical alternative for many concrete test environments.

Caution: If concrete weight is unknown, ALWAYS start with the LOW POWER settings for the Windsor® Probe System; otherwise excessive damage may occur to the concrete under test.

Windsor® Probe Concrete Strength Tables:

For In-Place Testing of Concrete at Standard and Low Power

Windsor® Probe Strength Table.pdf


Z-WP-1000 Windsor® HP Probe System

Approximate Compressive Strength Range (Varies with mix design)
1500 PSI / 10 MPA to 17000 PSI / 110 MPA
26 lbs / 11.8 Kg
Case Dimensions 20” x 16” 14” 510mm x 410mm x 356mm

Z-WP-700 Windsor Probe Electronic Unit w/Windsorlinx software

4 lbs
2 “AA’ Batteries
2x16 Trans. Reflective
Operating Temperature
32° to 122° F / 0° to 50° C
Software Windsorlinx - Windows PC Compatible / USB Interface Required

Z-WP-534 Windsor® HP Probe System

Approximate Compressive Strength Range (Varies with mix design)
1500 PSI / 10 MPA to 9000 PSI / 62 MPA
26 lbs / 11.8 Kg
Case Dimensions
20” x 16” 14” 510mm x 410mm x 356mm

Downloadable Documents:

Downloadable Software

Downloadable Instruction Manual

Frequently Asked Questions

Q. Why use three probes?

A. As with any quality control procedure, one is an indication, two is a comparison, and three is a statistically correct result.

Q. Can I use only one probe at a time?

A. Yes, this will usually be done on round columns, but you still need to take an average of 3.

Q. Is there more than one power load available?

A. No, but you can change the power level by pushing the probe and driver head down the barrel. Look in the instruction manual for this procedure.

Q. How do you know when to use low Power or Standard Power?

A. Use low Power for new concrete less than 3200 psi. Standard Power is used for mature (28 days) or for more than 3500 psi. Always change to Low Power if using Standard Power indicates less than 3000 psi.

Q. My probes will not stick in the concrete.

A. You may be hitting aggregate, not enough paste on surface, or driver head is not on probe.

Average Customer Review: Average Customer Review: 4.5 of 5 4.5 of 5 Total Reviews: 2 Write a review.

  1 of 3 people found the following review helpful:
5 of 5 Great Product December 5, 2011
Reviewer: George B. Frazier from Pheonix, NY United States  
Thank you for your expeditious response to my request for a new Windsor Probe certification card. I have been using your product since 1976 and have always been pleased with it's performance.

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  2 of 2 people found the following review helpful:
4 of 5 Quick and dependable results August 6, 2010
Reviewer: Mike Hufnagel from Chicago, IL United States  
The windsor probe is easy to operate and gives you quick results. James instruments has been great for fast service and calibration.

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