CSITC Completes 21st Round Trial
April 19, 2012 The 21st Round Trial under the auspices of the Task Force on Commercial Standardization of Instrument Testing of Cotton (CSITC RT 2012-1) was conducted from January to March 2012 (CSITC RT 2012-1). During the Round Trial, 66 testing facilities from all continents submitted results from 105 instruments.
This is the first CSITC Round Trial conducted without public funding, but solely financed by the participation fees.
Each round trial consists of five samples prepared by the U.S. Department of Agriculture (USDA) and sent to participating laboratories. Each sample is tested in each laboratory six times a day for five days for all six CSITC parameters of micronaire, length, length uniformity, strength, Rd and +b, resulting in a total of 900 measurements from each instrument. Results are downloaded electronically and sent to the Bremen Fibre Institute for evaluation.
Because of the large number of observations over a five-day period, the resulting pattern of results can be used for detailed diagnostic evaluation.
Laboratories are not given grades or pass/fail results, and all results are confidential. The purpose of CSITC round trials are to facilitate improvements in both accuracy and precision among cotton testing laboratories around the world.
The typical inter-laboratory variations achieved by instrument testing, given as standard deviations, were:
Laboratories are given an overall ranking, as well as rankings for performance on each of the six parameters.
Rankings are based on the results of each lab in coming closest to the mean (average) values for all laboratories participating in the Round Trial on all six parameters.
The range of scores for the combined properties among the 105 instruments was 0.15 to 4.93 (a score of zero would be perfect), and the median overall evaluation of combined properties was 0.50. This implies that any instrument with a rating lower than 0.50 is belonging to the 50% of the best instruments in the Round Test.
Optional Parameters
Besides the 6 parameters for ranking, an additional 4 parameters were included for information purposes: Short Fiber Index (SFI), Maturity, Trash Area and Trash Count. The inter-laboratory variations for the four additional parameters are higher than the variations for the 6 parameters approved by CSITC. Therefore, laboratories are not evaluated according to the extra four parameters. Nevertheless, the resulting deviations for each parameter provide useful information to market participants.
The typical inter-laboratory variations achieved by instrument testing, given as standard deviations, were:
Laboratories are also being informed as to what proportion of their test results are within a given limit for each parameter. This information provides additional practical information that will be useful in improving testing performance.
Average Percent of Results or Instruments Testing Within Established Limits:
Information about CSITC and overall Round Trial results (information for individual laboratories is confidential) is available at www.CSITC.org.
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