GB/T 26277-2021Test method for measuring electrical resistance of tyres (English PDF)

3.1 Connecting point

Any point on the rim or metal carrier plate that the leads of the resistance meter are connected to.

3.2 Test load

The force that is applied to the tyre by the rim, which is perpendicular to the metal

4.2 Resistance measuring meter

The resistance measuring meter shall bear at least 1000V power supply voltage; the range shall be at least 1012 ohm; the input impedance shall be at least 1014 ohm; and the accuracy shall be +/-5% of the range. The power loss on the tyre to be tested shall be no greater than 3W. When the resistance of the tyre to be tested is lower than 1010 ohm, the test current shall be no lower than 10-7 A, and the measurement voltage shall be no higher than 1000V.

4.3 Metal carrier plate

The metal carrier plate shall be flat and shall be of sufficient size to fully contain the full contact surface of the tyre to be tested under the test load, and of sufficient thickness to withstand the test load specified in 5.8 without producing a visible deformation. The metal carrier plate shall be made of conductive and corrosion-resistant metal materials (such as brass or stainless steel), and shall not use materials that are easily oxidized on the surface (such as aluminium, etc.); and the surface has no coating and no obvious oxidation or corrosion contamination. So as not to affect the accuracy of the test results.

4.4 Insulation plate

The insulating plate shall be made of polyethylene, polytetrafluoroethylene (PTFE) or an equivalent insulating material and shall have sufficient strength to support the test loads specified in 5.8 without visible deformation. Each edge of the insulating plate should preferably be at least 50mm wide relative to the metal carrier plate. The insulating plate shall be placed between the metal carrier plate and the bearing base.

The resistance between the metal carrier plate and the bearing base should not be lower than 1014 ohm; and in any case, it shall be at least 2 magnitudes greater than the resistance range of the tyre to be tested.

5.1 The test tyre shall be parked for more than 24h after vulcanization, and its

appearance quality shall meet the requirements of HG/T 2177.

5.2 The test rim should be a steel measuring rim.

5.3 The test environment temperature shall be 25 +5 -10°C, and the relative humidity shall

be no more than 60%.

5.4 For pneumatic tyres, the test air pressure shall be (80+/-5) % of the inflation pressure

corresponding to the maximum rated load indicated on the tyre sidewall.

to the metal carrier plate and the rim; and measure point by point.

6.3 Apply the test load specified in 5.8 to the tyre and rim assembly at the first

measurement point; and unload after 1min. The loading and unloading process described above shall be then repeated once.

6.4 Apply the test load to the tyre to be tested for the third time. After the load stabilizes

to the test load, immediately apply the measurement voltage specified in Table 1. If the resistance range of the tyre to be tested is unknown in advance, first apply a voltage of 1V and measure the resistance value. If the measured resistance value at this time is greater than 104 ohm, measure the tyre resistance by increasing the voltage according to Table 1. Record the measured tyre resistance value after applying the measuring voltage for 3min+/-10s. During the measurement, the measurement voltage and the test load shall be continuously applied until the final tyre resistance value is recorded. If the applied voltage and the measured tyre resistance are not within the corresponding range, then take the higher resistance value measured among them as the resistance value of the measurement point; and record the corresponding voltage. Unload the tyre after the measurement is completed.

6.5 Repeat the operations of 6.3 and 6.4; and measure the resistance of the remaining

measurement points in turn.

6.6 Record the resistance values measured at all measuring points, the maximum

value of which is taken as the tyre resistance value. Appendix C presents reference specifications for tyre resistance limits.

NOTE: Appendix D specifies the direct measurement method of tyre resistance on vehicles.