A Between-Instrument Comparison of Staple Crimp Frequency Measured by Crimp Meters

Abstract

 This paper provides estimates of the within and between instrument variances of Staple Crimp Frequency measured by a Crimp Meter. A set of 27 Sale Lots was selected to cover a broad range of staple crimp frequencies from the 3 wool-selling regions in Australia.

The average 95% Confidence limit was ± 0.31 crimps/cm. The average within-instrument variance was 0.0221 (crimps/cm)2 and the average between-instrument variance was 0.0035 (crimps/cm)2. The average Crimp frequency for the 27 Sale lots ranged from 1.7 to 5.9 crimps/cm.

The Analysis of Variance showed:

• no significant difference between replicates within crimp meter;
• no significant difference between crimp meters; and
• no interaction between wool and crimp meter for Staple Crimp Frequency.

These results indicate the Staple Crimp Frequency measurement is highly repeatable.

A procedure has been developed to enable reporting of two mean Staple Crimp Frequencies for Sale Lots that exhibit a bimodal (two hump) distribution but requires validation on a larger number of Sale Lots.

Citation

"A Between-Instrument Comparison of Staple Crimp Frequency Measured by Crimp Meters", David Crowe, Report RWG 02, Technology & Standards Committee, Raw Wool Group, Hobart Meeting, April 2005