Tribometers (Slip Test Meters) Compared
This page contains information about the world’s most used tribometers, or slip test meters.
Tribometer: Pendulum slip/skid tester
Approximate price, USD: $5,880.00
Slip resistance test methods: ASTM E303-22 or EN 16165 or AS 4663 and others. Endorsed by Ceramic Tile Institute of America (CTIOA).
Validation for pedestrian traction: Greater London Council Bulletins 43 (1971) and 145 (1985), in continuous use since 1971 and adopted by at least 50 nations.
Advantage: Well-validated against accident histories and long used with little controversy
Drawback: Bulky, heavy, requires 2-minute onsite assembly and skilled operator
Use: Primary standard for floor slip resistance testing in 50 nations, E303-22 floor and road slip resistance testing, and for Sustainable Slip Resistance testing
Approximate price, USD: $8,995.00 with FREE shipping in contiguous 48 United States
Slip resistance test method: ANSI A326.2 DCOF Acutest. Can also do ANSI B101.1 for dry SCOF testing only.
Validation for pedestrian traction: University of Wuppertal comparison with human traction, 72 test points including 12 surfaces, two contaminants, three shoe-bottom materials, correlation coefficient 0.93
Advantage: Printed and electronic records. Cost effective for QC and multiple points on a property. Very simple to operate.
Drawback: Measures DCOF up to 1.00 only. Dry tests not possible with some rubber test foot materials.
Use: Periodic monitoring and new flooring slip resistance quality control using dynamic coefficient of friction. For comparing surfaces, not assessing safety. For that, the pendulum is much more reliable.
Tribometer: Horizontal dynamometer pull-meter static
Approximate price, USD: Low cost but not recommended for pedestrian safety testing. Device not offered by SDA, although we do perform tests if requested.
Slip resistance test method: ASTM C 1028-07, now withdrawn
Validation for pedestrian traction: None. Can give highly deceptive results if applied to slip potential of pedestrian; J. Forensic Sci. March 2007, p. 400.
Advantage: Good workout: uses 50-pound weight lifted 112 times per test.
Drawback: As stated unanimously by ASTM Committee 21.06, not suitable for evaluating slip-fall potential. This standard was withdrawn in 2014, and anyone who promoted its use over the years should now be considered unreliable for all time. It always gave very suspect and unreliable answers, and anyone who did the test knew that back when they were promoting it’s use.
Use: Surface quality control checks by tile manufacturers, in plant or in field.
Tribometer: SlipAlert (now sold as iKnow Slip Meter)
Price, USD: $1,980.00
Slip resistance test method: Proprietary product — no ASTM standard required
Validation for pedestrian traction: Studies by British and Australian government agencies of SlipAlert vs. pendulum
Advantage: Much smaller, lighter, simpler, more rugged and less costly than pendulum
Drawback: Needs long path length. Also, cart may sometimes veer, bounce or spin, requiring repeating of some runs
Use: Surrogate where pendulum is not economical. Rapid monitoring by minimally trained staff. Visual demo.
Tribometer: Tortus III
Approximate price, USD: $6,598.00
Source of test: Proprietary product — no ASTM standard required. Endorsed by Ceramic Tile Institute of America (CTIOA).
Validation for pedestrian traction: University of Southern California Medical Center Study (Tortus II) published in J. Forensic Sci. March 2007, p. 400.
Advantage: Makes printed record. Cost effective for multiple points on a property. Can test short, narrow samples if needed
Drawback: May not assess hydroplaning potential for running person.
Use: Periodic monitoring, dry and wet, using hard and soft rubber test feet.
Tribometer: English XL (VIT)
Approximate price, USD: $4,200.00
The ASTM standard F1679-04e1, the only official test method using the Variable Incidence Tribometer (VIT, or English XL) was withdrawn by ASTM with no replacement in 2006 due to its inability to provide a reasonable precision statement; see what Wikipedia’s floor slip resistance testing page has to say about this “instrument” with poor precision that seems to be loved by full-time expert witnesses, who get paid to get the answer that will help win a lawsuit, the truth be damned. This instrument is highly popular amongst these professional “experts” because the result of the test can be easily and heavily influenced by the user to get the desired result. This makes it an excellent tool for an unscrupulous expert witness who needs to get the result desired by the attorney who hired him/her to run the test.
Here’s a video showing which instruments can be reliable for assessing the slip resistance of a floor: