According to the HD 605 S2 2008 test standard mentioned, There has two methods for the determination of UV stability of MDPE sheath: xenon arc lamp and fluorescent tube lamp. Test temperature will be 60 ±3℃ during UV exposure test or xenon arc lamp test. This test is to determine the UV stability of the sheathing material of the cable in the condition as manufactured, by means of measuring elongation at break in the condition as manufactured and after exposure to ultraviolet light.
Lamp Characteristic: Borosilicate inner and outer filter system (daylight simulation) and irradiance of 0.34 W/m2 at 340 nm
Test Temperature: (60 ±3)℃
Spray Cycle: 18 min of spraying with 102 minutes dry interval between spraying
Xenon Arc Lamp
Lamp Characteristic: Type E
Test Temperature: (60 ±3)℃ during UV exposure
Test Temperature: (50 ±3)℃ during condensation exposure
Cycle: 600 minutes of UV with 120 minutes of condensation
Fluorescent Tube Lamp
Method of Exposure to UV
● Samples shall be selected, prepared and tested in accordance with EN 60811 -1-1, Items 9.2.｜Resistance to UV Rays Standard HD 605 S2-2008
● Samples shall be exposed to UV light in accordance with the requirements of ISO 4892 series, using either of the above specific conditions : Xenon Arc Lamp｜Fluorescent Tube Lamp
Both of the following requirements shall be met after (500 ±5) hours exposure to UV light.
The difference between the median value of elongation at break after UV light exposure and the median value without such exposure, expressed as a percentage of the latter shall be less that +-30%
The median value of elongation at break after UV light exposure shall not be less than that specified for unaged test pieces in the relevant cable standard.
Resistance to UV Rays HD 605 S2-2008 , Test principle and definition of the light source: This test is based on the prolonged exposure of the flat surface of the outer side of the cable test specimens to ultra-violet rays.
The light source used should be such that in a dry atmosphere (relative humidity below 30 %) the exposed surfaces of the two flat surfaces of the test specimen, the side corresponding to the outside of the test specimen cable, receives a radiation in which the wavelength-dependent energy distribution complies with the values indicated on the curve (Figure 2.4.23).
To take account of the dispersion of the lamps and their ageing, the following tolerances are accepted, This radiation may be obtained with a xenon lamp fitted with quartz filters.
Resistance to UV Rays Standard DS/HD 605 S2 2008 for UV Test Chamber
Radiation obtained with a xenon lamp fitted with quartz filters.(Wave length -200nm- 800nm)
1) 20% in the area of UV radiation ( wavelength below 400nm)
2) 50% for the visible radiation ( wavelength above 400nm)
For the dispersion of the lamps and there aging following tolerances are accepted
1) Cycle -1 Humidity ≥85% at temperature 25±2°C for one day with sprinkling of water at a rate lasts 3 min per period 20min.
2) Cycle -2 Exposure for one day in a humid atmosphere at the temperature of 50±2°C with thermal shocks obtained by being put into an enclosure kept at -25±2°C for three one-hour period.
3) Cycle -3 Two days exposure to light radiation in a dry atmosphere at temperature 70±2°C and relative humidity ≥30%.
4) Cycle -4 Exposure of 8 hr with 0.067% in a volume of sulphur dioxide and kept at a temperature 40 ±3°C with saturated humidity.
The equipment shall be able to cover the following different cycles
1) Exposure for one day to light radiation in a humid atmosphere, (relative humidity more than 85%), at the temperature of (25 ± 2) °C with sprinkling; Resistance to UV Rays Standard HD 605 S2-2008
2) NOTE: The sprinkling of demineralized water lasts 3 min per period of 20 min; it is done with the aid of injectors in which the water discharge should be sufficient to ensure the washing of all the test specimens.
3) Exposure for one day in a humid atmosphere at the temperature of (50 ± 2) °C with thermal shocks obtained by being out into an enclosure kept at (-25 ± 2). °C for three one-hour periods. The rot-cold or cold-hot transfers should be done in the shortest time possbile.
• The samples shall follow a cycle of 5 days. During these days they shall be subjected to the following tests:
1) Two days exposure to light radiation in a dry atmosphere during which the temperature is kept at (70 ± 2) °C and the relative humidity isless than 30 %;
2) The fifth day, exposure for &Jl_ with 0,067 % in volume of sulphur dioxide and kept at a temperature of (40_± 3) °C with saturating humidity. For the last 16 h the door of the enclosure is left open to the laboratory environment.
• The time the test specimens remain in a humid atmosphere between two thermal shocks should be one hour or more.
1) During the exposures the test-pieces, similar to those defined for the tensile test, shall be placed on supports, taking care that they are not subjected to any tensile force in the UV test chamber
2) At the end of the test, the samples shall be removed and kept protected from direct sunlight in the laboratory atmosphere for 24 hour at least. A visual verification shall then be carried out to ensure that there is no significant discolouration between the aged test pieces and those not subjected to the test.
1) The reference batch shall be kept at ambient temperature avoiding direct sunlight throughout the environmental testing.
2) The other batch shall be subjected to the specified 5 days cycle and then conditioned like the reference batch for 24 h.
• The test requires two batches of six test-pipces; one of them being the reference batch.
Reference batch: Ao and R0; + Exposed batch: A1 and R1. HD 605 S2
• After the visual for any significant discolouration the elongation at break (A. … ) and tensile strength (R…. ) of the test-pieces from each of the batches shall be measured in accordance with EN 60811-1-1, 9.2, i.e. respectively: