Safety shoes anti-static measuring instrument principle and test method

The resistance of the conductive shoe was measured after conditioning in a dry environment and after conditioning in a humid environment.

test instrument
When the (100±2)V DC voltage is applied, the resistance can be measured to ±2.5% accuracy.

Internal electrode
It consists of stainless steel beads with a total mass of 4KG and a diameter of 5mm. Steel balls should take measures to prevent or remove oxidation of steel balls and copper plates, because oxidation may affect their electrical conductivity.

External electrode
It consists of a copper contact plate and is cleaned with ethanol before use.

Device for measuring conductive coating resistance
Consisting of three conductive metal probes, the probe has a radius of (3 ± 0.2) mm and is mounted on a base plate. The two probes are separated by (45 ± 2) MM and connected by a metal strip. The third probe is separated from the midpoint of the other two probe wires by (180 ± 5) MM and insulated from them

Sample preparation
If the shoe is equipped with an activity mat, it should be retained when testing. Clean the sole surface with alcohol to remove all traces of release agent and rinse with distilled water
Dry at (23±2)°C. The sole surface should not be rubbed or worn, nor should it be cleaned with organic materials that damage the sole or expand the sole.

Special preparation of wet conditioning
For the specimens adjusted under wet conditions, a conductive coating with an area of ​​200 mm x 50 mm was coated on the sole of the shoe, and the coated surface included the heel and the forefoot of the shoe. Dry measuring coating resistance value is less than 1 x 103 megohms
The shoe is filled with clean balls and placed on the device's metal probe so that the forefoot area of ​​the outsole is supported by two probes spaced 45 mm apart. The heel area is supported by the third probe and the probe is measured with a test instrument. The resistance value between the third probe and the probe.

According to the function of the tested shoe, adjust the prepared sample according to one of the following conditions.

1) Dry conditions, (20 ± 2) °C, relative humidity (30 ± 5)%. (Placed for 7 days)

2) Wet conditions, (20 ± 2) °C, relative humidity (85 ± 5)%. (Placed for 7 days)

If the test cannot be performed in a regulated environment, the test should be fully tested within 5 minutes after the sample is removed from the environment.

Test procedure
Fill the sample with a clean ball with a total mass of 4 KG. If necessary, use an insulating material to increase the height of the upper. Place a sample of the filled steel ball on a copper plate and apply a (100 ± 2) V DC test voltage between the steel plate and the steel ball for 1 minute and calculate the resistance value.

The energy consumption of the sole should not exceed 3 W. If the resistance to voltage reduction is considered due to the 3 W limit, the actual voltage value should be recorded on the test report.

China Labor Insurance Network