Determination of the reference distribution for laser diffraction (Approach 2)

For the laser diffraction measurements, both wet and dry, two types of results were collected:

• Your method (YM): the participants were requested to use the method that they normally use and to describe it in detail
• Specifications (SPEC): the participants were requested to repeat the measurements using parameters specified by NIST (Appendix D).

Therefore, we will examine the two sets of data separately and then in combination after excluding the outliers. As a result of this process, three mean bootstrap curves with 95 % confidence limits will be provided each for LAS-W and LAS-D. The issue is to decide which of these three distributions should be used as a reference for LAS-W and LAS-D. As shown in Figure 1 and Figure 2, the differences between the three distributions are not very large, and the combined distribution uses the largest number of data sets. Therefore, it could be argued that the combined PSD should be used as the reference curve. In this report, the combined distribution will be used to calculate the correction factors for the CCRL cements.