Report on the second Wool ComfortMeter round trial

The present report analysed the variance between instruments and estimated the measurement precision of the Wool ComfortMeter instrument by conducting an international round trial. The first international round trial was conducted in 2014; however the calculated precision estimates were relatively large. In the present trial, instruments were standardised by harmonising parameters such as wire height and measuring length, and a new calibration method was used to improve the measurement precision. The data from five laboratories, measuring ten fabric-samples and 5 sub-samples per fabric sample, was used to estimate the components of variance and the prickle measurement precision. The results showed good agreement between laboratory measurements. Analysis of the data shows an improvement in the 95% confidence limit for this round trial compared to the first round trial. Particularly, relatively smaller confidence limits were found for low prickle measurements. It is recommended that the new precision estimates be incorporated into the IWTO DTM-66:2014.