AASHTO T 282:01(2019) Standard Method of Test for Calibrating a Wheel Force or Torque Transducer Using a Calibration Platform (User Level)

AASHTO T 282:01(2019) Standard Method of Test for Calibrating a Wheel Force or Torque Transducer Using a Calibration Platform (User Level).
3.1.1. wheel force transducer system—a force-to-electrical signal converter system including transducer(s), associated signal condition, zeroing, amplifying, recording, and
monitoring instrumentation.
3.1.2. calibration reference signals—repeatable signals in the range of expected wheel-force transducer system loading. These signals could be either constant voltages (preferably) or produced by a strain-gauge calibration shunt resistor.
3.1 .3. calibration platform—a moving platform for applying a force in the contact plane of a tire, and associated means for measuring the applied force. The calibration platform consists of a rigid plate with a high-friction surface, in contact with the tire footprint, supported on a frictionless, preferably air, bearing. It may also be instrumented to measure vertical forces (loads).
3.1.4. hysteresis—the maximum difference between corresponding transducer outputs (of the wheel force transducer system) at increasing and decreasing applied calibration force, expressed as a percentage of full load. Proven outliers are excluded.
3.1.5. linearity/nonlinearity—the maximum deviation of the transducer output(s) (of the wheel force transducer system) from the bbestfit linear relation to the applied calibration force, expressed as a percentage of full scale. Proven outliers arc excluded.
3.1.6. test wheel—a wheel and test tire assembly mounted to a test vehicle by means of a force or torque transducer.
3.1 .7. crosstalk—the undesired effect of force readings appearing on an unloaded axis of a transducer while applying force to another.
3.1 .8. horizontal traction (traction)—a force acting in a horizontal axis through the wheel transducer, i.e., locked wheel drag force.
3.1.9. vertical load (load)—force acting in a vertical axis through the wheel transducer, i.e., weight.
4. SUMMARY OF METHOD
4.1. The vertical static loads (forces) on the test wheel(s) and hitch are established. If the tester is of the trailer type. it must be connected to its tow vehicle. Traction forces are applied to the locked wheel(s) at the tire—platform interface. The wheel transducer is calibrated while trailer and tow vehicle displacements are measured from the initial position for the applied traction force. The calibration platform consists of a bearing that is frictionless in all directions of the horizontal plane supporting a rigid plate with a high-friction surface. The force applied to this platform is measured by a suitable transducer.AASHTO T 282 pdf download.