Johnson Forensics GS-1


Quick Note: Save $499 if you purchase a GS-1 before March 31st

For orders of the GS-1 before March 31st, you get an additional $499 online course “GS-1 Operator Certificate Level 1” AT NO CHARGE.  If you have the Level 1 Certificate you can then attend the full-day in-person Level 2 course for $399 (regular $695).

SKU: 105 Category:


Download (PDF, 116KB)

Price includes:

  1. Free ground shipping within continental U.S. (additional shipping costs will be invoiced separately)
  2. GS-1 slip meter and case
  3. Windows-based tablet computer (Win 10)
  4. Online course “Operator Certification Level I” (regular price $499)
  5. 3-hour online “Flooring: Material Selection and Design Considerations for Health, Safety, & Welfare” (regular price $130)
  6. A326.3 test method
  7. A137.1 test method excerpt for COF
  8. For additional cost B101.1 and B101.3 test method standards can be added
  9. Reference tile
  10. Sled – mass that sits on sensor material (“shoe”) and pulled by slip meter
  11. Sensor material (“shoe”) – neolite, SBR, leather
  12. USB cable between GS-1 and tablet computer
  13. Power cable for GS-1
  14. Power cable for tablet computer

GS-1 Technical Specifications

  • Product: GS-1 Walkway Tribometer, Portable
  • Size: 12-1/2” X 5-5/8” X 5-5/8” (317 X 143 X 143 mm)
  • Weight: 7.3 Lbs (3.32 kGms)
  • Power: Internal NiMH Batteries
  • Battery Life: 3 to 7 years depending on usage.
  • Run Time on Single Charge: 20 hrs (approximate)
  • Recharge Time: Overnight
  • Charger: Provided with unit. 18 V +/- 3% DC, ½ A Min.
  • Internal Sensitivity: 1 part in 4096 (0.025%)
  • Repeatability: 1%
  • Accuracy: < 2%
  • Host: Works with any Windows-based computer running XP, Win 7, or Win 8.
  • Interface: USB Type B Port

GS-1 Features

  • Fully Automatic System
  • Internal Self Calibration
  • Operator Independent
  • Reproducible Results
  • Correlation With Force Plate Measurements
  • Concurrent Graphical Display as Data is Taken
  • Computer Operated & Controlled
  • Patent-Pending Technology
  • Scientifically Engineered by Johnson Forensic Lab

The GS-1 is the most technologically advanced, accurate and easy-to-use slip meter available today. Fully digital and automatic, it provides a wealth of detailed data at the push of a button. The GS-1 connects directly to your computer via USB for rapid analysis and permanent storage. Windows also has a feature that allows for screen capture of live video. This feature can be used to record all testing in real-time.

The GS-1 measures both the static and dynamic coefficients of friction, providing an accurate measurement of surface slipperiness in both dry and wet conditions while taking multiple sequential measurements to ensure the highest level of accuracy and to produce an average slip coefficient value. It provides the raw data as well as automatically calculated findings can be saved and printed onto an 8.5 x 11 inch paper appropriate for written reports and courtroom presentations. The GS-1 relies upon unique, patent pending technology to seamlessly integrate a comprehensive range of features far beyond what other tribometers offer.

For the professional seeking the most accurate and true COF measurements, the GS-1 is the most versatile and powerful option.


GS-1 Operator Certificate Course Level 1

Download (PDF, 112KB)

Flooring: Design Considerations and Material Selection for Health, Safety, & Welfare

Download (PDF, 1.99MB)


Additional information

Weight20 lbs
Substratum Group