1. Insulation resistance, conductor resistance ρ≤4.95Ω/km, 20°C; sheath surface resistance ρ≥109Ω.cm.

        2. The pressure test water temperature is 20±5℃, the immersion length is 10M, the time is 1H, the AC power frequency voltage is 8000V, and it is stored for 5 minutes without failure.

        3. Combustion test Vertical combustion test: the distance between the upper fixed point and the carbonization starting point is more than 50 mm. The distance from the lower flame to the upper fixed point is less than 540 mm. Combustion gas corrosion test: PH value ≥4.3, conductivity ≤10μS/mm.

        4. Tensile test of internal insulation mechanical properties before aging: tensile strength ≥5N/mm2, elongation at break ≥200%; after aging (135±2℃), the change in tensile strength ≤±30%, elongation at break Rate and elongation ≤ ± 30%; aeroelastic aging tensile test: air pressure 5.5 bar (127°C) tensile strength change ≤ + 30%, elongation at break change ≤ + 30%; thermal elongation test: oven The elongation at a temperature of 250±3°C, mechanical pressure under a load of 20N/cm 2 is 100% or less, and the elongation after unloading is 25% or less.

        5. The mechanical properties of the sheath. Tension before aging: tensile strength ≥10.0 N/mm2; elongation at break ≥300%; after aging (85±2°C): elongation at break ≥250%; change in tensile strength ≤±-15%; Change in elongation at break ≤-25%.

        6. Weather resistance test. Sheath low-temperature bending test: the temperature of the refrigerating room is -40±2℃, 16 hours, and there is no crack after the test. The internal insulation and ozone resistance of the sheath: ozone concentration 250-300pphm, 24 hours, 180° to ensure that there is no crack in the bend. The weather resistance of the sheath: water spray for 18 minutes, dry xenon lamp 102 minutes, test temperature 45±5°C, total test time at least 500 hours, then 7.1 bend test at room temperature, no cracks..

        7. After being immersed in oil, the secondary oil resistance (ISO1817) test, the compressive strength retention rate is 60% or higher. The retention of tensile elongation after oil immersion is above 70%; the diameter change after oil immersion is less than or equal to 160