ISO 13787:2003 pdf download
ISO 13787:2003 pdf download.Thermal insulation products for building equipment and industrial installations 一Determination of declared thermal conductivity.
5.1 Measurement of thermal conductivity
The test specimens shall be aged, if necessary, before measurements are made. As an alternative, a correction factor for ageing shall be applied.
NOTE Ageing procedures are found in product specifications, where relevant.
Measurements shall be carried out in accordance with ISO 8301, ISO 8302 or EN 12667 for flattest specimens and EN ISO 8497 for cylindrical test specimens.
The temperature difference between the hot and cold faces shall range from 10 K to 40 K for flat test specimens. The temperature difference shall be chosen to maximize the accuracy of the measurement. For cylindrical specimens, tested in accordance with EN ISO 8497, these requirements on temperature difference do not apply, but the temperature difference shall not be smaller than 10 K.
Measurements shall be made at three different mean temperatures at least.
For mean temperatures up to 500 °C, the curve determined in the test shall be based upon measurements at intervals of a maximum of 100 K, over the whole service temperature range stated by the manufacturer.
Thermal conductivity shall also be measured at temperatures close to inflexion points or other irregularities of the curve.
For mean temperatures greater than 500 °C, the curve determined in the test shall be based upon measurements at intervals of a maximum of 200 K.
No extrapolation of test results beyond the measured temperature range is permitted. The measured thermal conductivities shall be rounded up to the nearest 0,001 W/(m•K).
The results shall be expressed either by a temperature/thermal conductivity curve or by a table. The comparison with the proposed curve or table is only made at the temperatures of measurement.
5.2 Procedure for verification
Select three different samples. Take the test specimens from these samples at random, as required. Measure the thermal conductivity of the test specimen from the first sample in accordance with the method described in 5.1.
Compare the results of the measurements with the values obtained from the proposed curve or table.
— If the measured values are all less than or equal to the thermal conductivities derived from the proposed curve or table, the test is passed and the proposed curve or table becomes the declared curve or table.
— If one or more of the measured values exceeds the corresponding thermal conductivity of the proposed curve or table by 10 % or more, the test has failed.
— If there are measured values above the values on the proposed curve or in the table but none of them exceeds the corresponding thermal conductivity by 10 %, then two new test specimens shall be measured in accordance with the method described in 5.1, one specimen being taken from each of the two remaining samples.
For temperatures below 100 °C, measure the thermal conductivities of the second and third specimen at temperatures within ± 5 K of the values measured for the first specimen. Increase this to ± 10 K for temperatures above 100 °C.
If none of the new measurements exceeds the proposed curve or table by 10 % or more, the measured thermal conductivities shall be converted to the temperatures at which the measurements for the first curve were made, using the slope of the first curve to make the conversion.
Results of the measurements above the proposed curve or the value in the table by 10% or more shall constitute a failure of the test.
Calculate the values of thermal conductivity at the corresponding temperatures by calculating the mean of the three values measured or converted at each temperature.
If all these new mean values are lower than or equal to the corresponding thermal conductivities of the proposed declared curve, the test has passed, in which event the proposed declared curve or table becomes the declared curve or table.
— If one or more of the new mean values is higher than the corresponding thermal conductivity of the proposed declared curve or table, the test has failed.
The verification procedure is described in the flow chart in Figure 1 and illustrated in annex C.
