ISO TR 19032:2019

ISO TR 19032:2019 pdf free.Plastics一Use of polyethylene reference specimens (PERS) for monitoring laboratory and outdoor weathering conditions.
After finishing the exposure test, specimens were measured to calculate carbonyl indices at each laboratory, and returned to the reference organization (Japan Weathering Test Center). In this reference organization, the characteristic values were measured by a single operator with a single item of equipment.
As shown in Table 5, the data of the reference laboratory showed the same tendency as the data of each laboratory. Mean values and standard deviations of each laboratory and of the reference laboratory were almost the same. This means that even if the position of the films, measurement apparatus, and operators are different, almost the same results can be obtained.
Each laboratory’s data were plotted together with those of the reference laboratory in Figure 2. All data showed linear relations between carbonyl indices (CI) and testing hours. The correlation coefficients were 0,95 or more.
The slope showing the relation between testing hours and CI differed between items of equipment, and this is collectively indicated in Figure 3. Eight of 14 different items of equipment demonstrated slopes in a range from 0,009 to 0,0 11, another two were less than 0,0 09 and the remaining four were more than 0,011.
On the other hand, the relation between slopes and chamber temperatures was examined. As a result, the temperatures of eight items of equipment ranged from 38 °C to 43 °C, and the temperature of the equipment having the maximum slope was as high as 50 °C, as opposed to the equipment with the minimum slope indicating 30 °C.
From this fact, the chamber temperature has a great influence on the slope. If the chamber temperature is not kept constant, even though items of equipment are controlled with a UV radiometer and BST or BPT, the result obtained would vary (see Reference [5]). Thus, a quantitative indication of exposure environments obtained through PERS is vital for the reproducibility of the experiment.
The Arrhenius plot of the chamber temperature and slope is shown in Figure 4. The activation energy calculated was about 35 kj/mol, which was consistent with previous studies (see References [6] and [7]. All these data include BPT and BST and the higher point also had a higher BPT. PERS is susceptible to chamber temperature, therefore, if PERS was used, it is able to indicate the different chamber conditions.
The results of analysis of variance in data from all laboratories participating in the RRT are shown in
Table 6. The variances between laboratories were about 98 %, so this means that the difference of the test results was attributable to exposure itself.
Although this RRT unified the test conditions of UV intensity and BST or BPT, the chamber temperatures  were different among laboratories, and therefore, different slopes were mainly due to differences in the chamber temperatures of equipment.
Three devices from three organizations of two nations, Japan and the USA, participated.
The result of open-flame carbon is shown in a Figure 5. Three organizations participated. The data
from every organization indicated linearity and a correlation coefficient of 0,95 or more. In these
three devices, the reported BPT was the same. Therefore, it is thought that it reflects the difference of chamber temperature. The slope is larger than for the xenon-arc lamp. It is based on difference of light intensity, difference of spectral distribution, difference of chamber temperature, etc.
Five devices from four organizations of three nations, Japan, the USA and Switzerland, participated.
Figure 6 represents the results of an ultraviolet fluorescent light test in which five organizations
participated. For the test conditions, a repeat of a cycle composed of 4 h irradiation and 4 h darkness
was used, which means that the period when UV is irradiated is half of that for other light sources.
The results show that the linearity is not as good as for other light sources, and the data after 24 h
exponentially increased despite the half of UV irradiation. The reason that this phenomenon occurred is because temperatures in the chamber were kept at about 50 °C during darkness, whereby a reaction in PERS proceeded. Thus, in this case, it cannot be said that it is proportional to the exposure environment.ISO TR 19032 pdf download.

Leave a Reply

Your email address will not be published. Required fields are marked *