Tribo (physics)
prefix
Pertaining to, or resulting from friction.
[Gr. tri`bein to rub.]

-meter
suffix
Measuring device: anemometer.
[French -mètre, from Greek metron, measure.]


Tribometer (Webster 1913)
noun
[Gr. tri`bein to rub + -meter: cf. F. tribomètre.]
An instrument to ascertain the degree of friction in rubbing surfaces. Brande & C.

Tribometry is the measurement of friction.
Tribology is the science or the study of friction.
The methodology of precision repeatable and reproducible measurements of friction and wear is called tribometrology.

Early tribometer designs from Leonardo da Vinci

Modern industrial tribometers such as the CETR UMT-3 (shown) can perform practically all common tribological tests, with many different materials, and under a large variety of controlled environmental conditions and lubricants. This type of laboratory tribometer would not be ideal for everyday field testing.

Most portable tribometers are used for measuring the available friction of flooring or walkway surfaces.

Calculating the coefficient of friction, or COF is simply dividing the amount of force it takes to move an object (F) by the Normal force (N) which is basically the overall weight of an object. So if it requires one pound of force to push or pull a two pound object; you have a COF of 0.5

There are two well-known types of COF; static (SCOF) and dynamic (DCOF). The static test is only interested in how much force it requires to get an object to move or budge (slip), while the dynamic test is interested in how much force it requires to keep the object in motion (slide). Historically, SCOF testing is common in the US, while DCOF is prevalent in Europe.

The BOT-3000 can perform both SCOF and DCOF test types, wet or dry; with a variety of sensor (test foot) materials.

Click image to learn more about friction

Both SCOF and DCOF are valuable indicators of the available friction of a walkway surface. You need a good SCOF level to help “grab” the floor surface as you step, but a good DCOF level helps prevent a small slip event from becoming a more dangerous slide event, which can result in a fall. Unlike other devices, the BOT-3000 measures both SCOF and DCOF utilizing the same test platform. This is very useful in formulating accident prevention strategies for more knowledgeable risk or safety managers.

PROGRAMMED TEST TYPES: WET / DRY / SCOF / DCOF (FLYING HEEL OR USER-DEFINED TEST RUN DISTANCE)

RANGE: (SCOF, DCOF): 0.00 – 1.00 µ

RESOLUTION: 0.01µ

SAMPLING RATE: 1000 HZ

STRAIN GAGE TYPE: 0 – 25 NEWTONS, 2% ACCURACY – BENDING BEAM

A/D CONVERTER: 10 BIT

OPERATING / STORAGE ENVIRONMENT: 50 – 100 DEGREES F, 10% - 80% RH

POWER SOURCE: 12VDC, 2A SEALED LEAD ACID BATTERY

RECHARGE TIME: APPROX. 12 HRS. WHEN FULLY DISCHARGED

DIMENSIONS: 11.5 X 7 X 4.5

UNIT WEIGHT: 17 LBS.

FWD. SPEED: 20 CM / SECOND (DCOF MODE)

RAMP ANGLE: 9.6 DEGREES MAXIMUM (DECLINATION)

PRINTER TYPE: HIGH SPEED / HIGH RESOLUTION THERMAL

DISPLAY TYPE: 2 ROW X 16 CHARACTER BACKLIT LCD

DATA INPUT: 6 BUTTON KEYPAD

PRINTOUT INFORMATION: TEST METHOD (WITH SCALE), LAST CALIBRATION / VERIFICATION DATES,  SENSOR INFORMATION, TEST RESULTS (MIN, AVG, MAX VALUES), FACILITY CODE, TEST SAMPLE GRAPHS

STANDARD ACCESSORIES INCLUDED: HEAVY-DUTY WATERPROOF TRAVEL CASE, LEATHER SENSOR, NEOLITE SENSOR, SENSOR CLEANING BRUSHES, 120VAC CHARGER, VERIFICATION MASS, SENSOR VALIDATION TEST PANEL, USER MANUAL, THERMAL PAPER

OPTIONS: SERIAL DATA COM PORT (RS-232) FOR PC 

Click on image icon below to download a report sample

 

(DCOF_WET_PRINTOUT.gif

The image shows a DCOF test report using the optional PC interface. The BOT-3000 will provide identical test result data from the internal printer as well!

Various types of precision measuring instruments and devices require annual (if not more frequent) calibration services to be performed. This is important simply because things change. Many factors can affect the degree of change over time. Temperature variations, moisture, shock, vibration, mechanical stress (often by design), etc, play a role in the output accuracy and longevity of a device. Anyone who plays a piano, violin, or other stringed musical instrument knows that it may require periodic tuning even if it is rarely played. Some devices actually fare better with use rather than neglect. This is because some components in a mechanical system are often under a degree of preload condition and are potentially subject to developing the “mechanical memory” effect. This occurs at a molecular level. Many precision measurement instruments are designed to overcome the effects of change through periodic adjustments or calibrations. The BOT-3000 alerts the user when it is time to return the unit to the factory for the annual calibration and evaluation service. If the unit is not re-calibrated by the due date, a text will appear on each test result printout indicating an “out of calibration period” status.

DCOF results with Tek Stil high traction ESD vinyl flooring

DCOF results with common smooth ceramic tile

SCOF results with common smooth ceramic tile

SCOF results with Tek Stil high traction ESD vinyl flooring

Click to view summary

COF Samples2.jpg