BS EN 15426-2018 pdf free download.Candles – Specification for sooting behaviour
5.12 Calibration disk, made of dark neutral density glass (e.g. NG4 3) ) having a wavelength- independent optical absorption coefficient of (1,20 ± 0,10) mm−1 and dimensions (20 ± 0,3) × (20 ± 0,3) × (2,4 ± 0,3) mm3.
6 Sampling The test shall be carried out on finished candles representative of those intended to be supplied commercially. For the test result to represent a specific candle type, a minimum of three samples shall be tested.
7 Sample preparation
Remove any outer wrapping and label material and prepare the sample for use according to the manufacturer’s instructions if any given, e.g. trim the wick. For identification of the sample, measure the dimensions and mass of the candle.
The temperature of the sample shall be (20 ± 5) °C before the test is started. 8 General test conditions The room temperature at which the burning test is to take place shall be (20 ± 5) °C.
The room shall be draught free. If during the test the temperature is outside the range, the maximum and/or minimum temperature shall be recorded in the test report. For testing floating candles, the temperature of the water shall be (20 ± 5) °C when the test is started. NOTE Draught free means that a candle can burn without noticeable disturbance of the flame. If the flame is flickering this can be verified using a reference candle such as a paraffin candle with a diameter of 22 mm. If this reference candle is also flickering there is a draught, if not then the tested candle is flickering due to the candle design or quality.
9 Test method
9.1 General In the case of candle designs not catered for in the test procedures, the test should be carried out as far as possible as described and deviations from the test procedure shall be recorded in the test report.
If sooting becomes excessive the measuring may be stopped early.
9.2 Test preparation
The wire mesh cylinder type shall be selected according to Table 1. The diameter of the candle is measured at the largest cross-section at any point from 50 mm below the bottom of the cylinder to the top of the candle when the candle is placed in correct position for the test, as the air exchange within the cylinder would otherwise be hindered. For non-circular candles the cylinder is selected based on the same cross-section as for the diameter of a circular candle, see Annex C.
Set up the apparatus on an even surface and select a heat resistant surface or base for the candle to stand on.
9.3 Burning test Place the candle in an upright position on a heat resistant, non-flammable surface
. Non-freestanding candles are placed in a suitable candleholder which does not affect the burning properties of the candle 4) . Freestanding candles are placed on a surface that does not affect the burning properties 5) . Floating candles are placed in a suitable bowl filled with water. The bowl is made from a heat resistant material in a size so that the floating candle is kept in position under the glass plate during the entire test and filled with water to a level less than 1 cm below the rim.
The measuring periods are carried out without extinguishing the candle after the stabilizing period. Position the wire mesh cylinder centrally above the sample. Adjust the distance (l2) between the top of the solid base material and the glass plate to a minimum of 180 mm (see Figure 3). A gap (l1) of at least 50 mm shall remain between the bottom of the cylinder and the surface the candle is positioned on. If the gap is smaller the candle shall be placed on a stand to put it in a higher position. The diameter of this stand (l3) shall not exceed 1/3 of the diameter of the wire mesh cylinder, as the air exchange within the cylinder would otherwise be hindered (see Figure 3). Position the wick in an upright position and light the candle. After the stabilizing period, place a cleaned glass plate in the holder of the wire mesh cylinder.
The test cycles shall be chosen for different candle types according to Table 2. If the distance between the surface of the molten fuel pool and the glass plate (l2) exceeds 240 mm during the burning, adjust accordingly. When the measuring period ends, remove the glass plate before extinguishing so that smoke from the afterglow does not affect the test result. Record the start and end times of the stabilizing periods, measuring periods and pauses. Check the distance between the top of the solid base material of the candle and glass plate prior to each test period and adjust to a minimum of 180 mm, if necessary. The stabilizing period takes place without the glass plate.
When the measuring periods are complete, remove the glass plate before extinguishing the candle and allow the glass plate to cool down.
CAUTION — The glass plate can be hot.BS EN 15426 pdf download.