INTERWOOLLABS' activities have been crowned by official recognition from the International Wool Textile Organisation of its IH calibration standards as official I.W.T.O. calibration standards for Air-Flow, Projection Microscope, Laserscan and O.F.D.A. measurement apparatus.

The first series was established in 1972. It was the result of the most extensive testing and retesting that significant quantities of standard wool tops have been established. Limited to a maximum duration of 3 years, this series has replaced by fifteen further series, each of them having been valid for a period progressively reduced to 2 years. The 16th series will be valid until January 31st 2008, with respective finenesses as follows :

17th SERIES OF IH-STANDARDS
(Valid : 01.02.2008 - 31.01.2010)

Standard Values to be used for the calibration of the Instruments for the fibre diameter measurements

STANDARD VALUES

AIRFLOW

for AIRFLOW Calibrations

PROJECTION MICROSCOPE

for OFDA and LASERSCAN
Calibrations
Standard
No.
Mean fibre Diameter
(µm)
Mean Fibre Diameter
(µm)
Distribution of fibre diameter
(CV %)

Fibre
Curvature # (deg/mm)
1 PM
not applicable
15.71
20.00
79
1 AF
16.46
not applicable
not applicable
not applicable
2
18.54
18.52
19.76
79
3
20.40
20.29
19.92
70
4
23.80
23.73
21.47
57
5
26.86
26.94
23.36
58
6
29.43
29.65
25.74
51
7
33.86
34.11
25.87
45
8
36.64
36.76
26.31
44
Eight Tops are required to calibrate Airflow (IWTO-6), Laserscan (IWTO-12) and OFDA (IWTO-47).

- To calibrate Airflow Instruments, tops "1AF" and "2" to "8" only shall be used.
- To calibrate Laserscan and OFDA Instruments, tops "1PM" and "2" to "8" shall be used. Do not use top "1AF"

# IWTO is moving towards providing a calibration procedure for Fibre Curvature measured by OFDA and Laserscan and as a consequence Interwoollabs has been requested to provide indicative Fibre Curvature Values for the calibration tops.

A software programme for the calibration of the Air-Flow has been prepared by Professor HARIG from the Faserinstitut Bremen, and offered to all Members of INTERWOOLLABS free of charge.

Thus all Members are expected to use the same parameters to check the calibration of their apparatus.