BS ISO 20360:2020 pdf free.Brown coals and lignites一Determination of the volatile matter in the analysis sample: one furnace method.
BS ISO 20360  Furnace, heated by electricity, in which a zone of uniform temperature of 900 °C土5 °C can be maintained (see Figure 1, which is the same as the one given in ISO 562:2010 Figure 1).It may be of the stop-ended type or fitted at the back with a flue approximately 25 mm in diameter and 150 mm in length.It is important for furnaces with flues that the furnace door seals well. The flue should not reach far out of the oven and should be fitted with a butterfly valve to restrict airflow through the furnace.The heat capacity of the furnace should be such that, with an initial temperature of 900 °C, the temperature of 900 °C士10 °C is regained within 3 min after insertion of a cold stand and its crucibles.The temperature shall be measured with a thermocouple as described in 6.2. The initial temperature of 900°C may be adjusted to a temperature determined by calibration that will guarantee the furnace
temperature of 900 °C土10 °C is regained within 3 min after insertion of the cold stand and its crucible(s).The furnace is designed specifically either for multiple determinations using a number of crucibles in one stand or for receiving one crucible and its stand. In the first case, the zone of uniform temperature shall be at least 160 mm x 100 mm; in the latter case, a zone with a diameter of 40 mm is sufficient.A position for the crucible stand shall be chosen within the zone of uniform temperature and this position shall be used for all determinations.The thermo-junction shall be inserted midway between the base of the crucibles in its stand and the floor of the furnace from which there is 20 mm to 30 mm distance. If the stand holds more than one crucible, the temperature under each crucible shall be checked in the same manner.If desired, a sheathed thermocouple may be permanently installed in the furnace with the thermo-junction as close as possible to the centre of the zone of uniform temperature; in this case its temperature readings shall be correlated at frequent intervals with those of the unsheathed thermocouple, which is thus inserted only when necessary.BS ISO 20360 pdf download.