BS EN ISO 2233:2001 pdf – Packaging — Complete, filled transport packages and unit loads — Conditioning for testing.
5 Tolerances 5.1 Temperature 5.1.1 Tolerance on peak values For conditions 1 , 2, 3 and 1 0, the maximum permissible temperature difference of ten measurements distributed about the nominal value over at least 1 h shall be ? 3 °C. For all other conditions the maximum permissible difference shall be ? 2 °C. 5.1.2 Tolerance on the mean For all conditions, the tolerance on the mean in relation to the nominal value shall be ? 2 °C. NOTE 1 When using condition 4, care should be taken to ensure that the dew point is not reached. NOTE 2 Temperature tolerances quoted are not necessarily those required to maintain the required tolerances on relative humidity; closer temperature tolerances may therefore be necessary in order to comply with the tolerances required for relative humidity. 5.2 Relative humidity 5.2.1 Tolerance on peak values For all conditions with a humidity requirement, the maximum permissible relative humidity difference of ten measurements distributed about the nominal value over at least 1 h shall be ? 5 % RH. 5.2.2 Tolerance on the mean For all conditions, the tolerance on the mean in relation to the nominal value shall be ? 2 % RH. NOTE 1 The mean value of relative humidity may be obtained by taking the average of a minimum of ten measurements over a period of 1 h, or may be derived from a continuous instrument trace. NOTE 2 The tolerance of ? 5 % RH is quoted as this represents the maximum variation to be expected in conditioning chambers. Modern, well designed, conditioning chambers are capable of maintaining ? 2 % RH. The response of most test specimens to changes in atmospheric moisture is relatively slow compared with the fluctuations of relative humidity within the chamber and, provided that the relative humidity within the working space, taken over any 1 h period during the duration of the test, lies within ? 5 % of the specified relative humidity, it may be assumed that the wider fluctuations, such as may occur on opening the door, 6 Apparatus 6.1 Conditioning chamber, having a working space the temperature and humidity of which is continuously recorded and which can be maintained at the specified conditions within the control tolerances given in clause 5. The working space is that part of a conditioning chamber within which the specified controlled conditions are maintained. The boundaries of this space shall be specified for each chamber. 6.2 Drying chamber, if necessary, to reduce the moisture content of certain test specimens to below that which will be attained by conditioning. 6.3 Measuring and recording apparatus, sufficiently sensitive and stable to allow measurement of temperature to an accuracy of 0,1 °C and relative humidity to 1 %. For the purposes of this International Standard, the record is deemed continuous if the period between individual readings is not greater than 5 min.
7 Procedure 7.1 Select the temperature and relative humidity conditions most appropriate to the transport and storage of the test specimen to be tested. Place the test specimen within the working space of the conditioning chamber (6.1 ) and expose it to the specified conditions for a minimum period which shall be selected from 4 h, 8 h, 1 6 h, 24 h, 48 h or 72 h or from 1 week, 2 weeks, 3 weeks or 4 weeks. 7.2 Support the test specimen in such a way that the conditioning atmosphere has free access to the top, sides and at least 75 % of the base. The conditioning period is deemed to start 1 h after the specified conditions have been regained. 7.3 When the test specimen is constructed of materials, such as fibreboard, that are known to show a hysteresis effect in their characteristics, it may be necessary to pre-dry before conditioning. This shall be done by placing the test specimen for a minimum period of 24 h in the drying chamber (6.2) in conditions such that, when transferred to the test conditions, it will approach equilibrium by taking up moisture. This is not necessary when the specified relative humidity is 40 % or below. 8 Test report The test report of tests on conditioned, complete, filled transport packages and unit loads, such as impact tests, stacking test and vibration tests, shall include the following information: a) a reference to this International Standard; b) the details of any pre-drying; c) the conditions (see Table 1 ) and time used for conditioning; d) the temperature and relative humidity of the test area at the time of test; e) any deviation from this International Standard.