Washington, DC
July 3, 2008
Source:
International Cotton Advisory
Committee
The sixth Round Trial conducted
under the auspices of the Task Force on Commercial
Standardization of Instrument Testing of Cotton (CSITC RT
2008-1) was conducted during May and June 2008. 63 testing
facilities with 85 instruments participated. Participating
testing centers were located in Africa, Asia, Australia, Europe,
North America, and South America. In each Round Trial, five
cotton samples with known values are mailed to each
participating laboratory. Each laboratory tests each sample six
times each day for five days, for a total of 150 tests. Each
sample is tested for the six CSITC parameters of length, length
uniformity index, micronaire, strength, Rd (reflectance) and +b
(yellowness). Accordingly, 900 separate test results (150 tests
of 6 parameters) from each instrument are evaluated.
In the sixth Round Trial, all five of the samples were from
upland saw ginned cotton.
CSITC Round Trials have a unique purpose in the world cotton
industry. Round Trials conducted by the Bremen Fiber Institute
are intended to evaluate the accuracy of different kinds of
testing instruments. USDA Check Tests provide information to
participants on the consistency of test results compared to USDA
established values. CSITC Round Trials facilitate improved test
center performance by facilitating standardization of results
from test centers around the world, and the large number of
tests performed over five days makes detailed diagnostic
analysis possible. The Bremen, USDA and CSITC Round Trials are
complementary.
Laboratory results for each Round Trial are collected by USDA
and forwarded to the Bremen Fibre Institute for evaluation.
Laboratories are given an overall ranking, as well as rankings
for performance on each of the six parameters. Rankings are
based on the first four upland cotton samples with known values.
The purpose of the fifth cotton sample in all CSITC Round Trials
is for special study purposes and is not used for
performance-ranking.
Results for each test center are confidential, but each testing
facility received an evaluation of its performance in the Round
Trial and a detailed diagnostic analysis of results.
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 measurements. The range of scores
for the combined properties among the 85 instruments was 0.21 to
4.49 (a score of zero would be perfect), and the median overall
evaluation of combined properties was 0.45. The results in CSITC
RT 2008-2 are consistent with the results from the first five
Round Trials conducted in 2007 and early 2008. However, the
median Combined Properties Score in 2008-2 was lower than the
median score from 2008-1, which was 0.51.
The typical inter-laboratory variations achieved by High Volume
Testing, given as standard deviations, were:
CSITC RT 2008-2
|
Property |
Standard Deviation based on Single Tests |
Standard Deviation based on 30 Tests/Sample |
|
Micronaire |
0.09 mic |
0.07 mic |
| Strength
|
1.34
g/tex |
1.06
g/tex |
| Length
|
0.017
inches |
0.012
inches |
| Length
Unif. |
0.79
units |
0.46
units |
| Color Rd |
0.96
units |
0.91
units |
| Color +b |
0.33
units |
0.30
units |
Summary Tables Available on the
Web
Summary tables from the first six CSITC Round Trials are
available on the web site:
www.ICAC.org.
The summary includes:
- Inter-laboratory averages
and variability and in-laboratory variability for each of
the 6 properties and each of the five cotton samples.
- Graphs showing the
distributions for every property and each cotton.
- A summary list of the
combined properties evaluations.
- A summary list of the
evaluations for each property.
Benefits of Participation
Participants in CSITC Round Trials benefit from detailed
feedback that can be utilized to demonstrate measurement
performance to customers and to address measurement related
problems. Results will confirm the participant's ability to
provide reproducible test measurements that are based on the
established international standard. In addition, participation
is a recommended practice for fulfilling quality management
requirements in laboratories (e.g. ISO 17025).
The CSITC Round Trials complement, but do not replace, the
Bremen Cotton Round Trial and the USDA HVI Checktest.
Participation in CSITC Round Trials provides numerous benefits:
- Statistically robust
evaluations of instrument performance based on 4
cottons and 30 tests per cotton during each Round Trial,
- An overall rating of
instrument accuracy in comparison with elite testing
facilities worldwide,
- Unique quarterly and
annual certificates of laboratory participation and
instrument ratings, and
- Detailed diagnostic
evaluations of instrument performance of a range of
parameter values.
Nevertheless, participation in the
Bremen and USDA programs remains meaningful. The Bremen Round
Trial is not limited to High Volume Testing and allows
evaluation of all cotton testing instruments free of cost. The
USDA HVI Checktests are conducted monthly, rather than
quarterly.
Round Trial Cost & Sign-Up
Participation in the CSITC Round Trial is subsidized by USDA,
the Bremen Fibre Institute and the ICAC Secretariat. Support is
also received from the Common Fund for Commodities and the
European Commission through the CFC/ICAC/33 project. A nominal
fee of US$300 per year for four trials is charged to cover
expenses associated with sample distribution.
To participate in future CSITC Round Trials, contact:
International Cotton Advisory Committee - CSITC
Email:
CSITCsecretariat@icac.org
Fax: 202-463-6950
10th CSITC Meeting
The Task Force on CSITC will meet on Sunday, November 16, 2008
in Ouagadougou, Burkina Faso in conjunction with the 67th
Plenary Meeting of the International Cotton Advisory Committee.
The Task Force consists of 18 members representing all segments
of the world cotton industry. Observers are welcome, but
observers must notify the ICAC Secretariat of their interest by
sending an E-mail to
CSITCsecretariat@icac.org.
The International Cotton Advisory Committee is an association
of 44 governments of countries with an interest in cotton. The
Secretariat of the Committee publishes information related to
world cotton production, supply, demand and prices, and provides
technical information on cotton production technology. Detailed
statistics are found bimonthly in COTTON: Review of the World
Situation, $180 per year via email, $215 per year in hard copy.
A monthly outlook is available by email for $285 per year.
Access to the latest weekly estimates of world cotton supply and
use by the Secretariat is available on the Internet for $450 per
year. Access Secretariat reports at www.icac.org. |
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