Interlaboratory tests on thermal foot models
Author
Summary, in English
A limited Round Robin test has been carried out with different types of foot models.
Eight laboratories were able to carry out tests. The foot models varied in sizes from 254
mm to 275 mm, representing boot sizes from 41 to 44. Six other laboratories were
interested but were not able to carry out the tests within this study. A database has been
created. New test results from other test laboratories and on other footwear can be added
later on. The test series were carried out under standardised conditions in each
laboratory. Ten (10) test conditions were recommended. All conditions had to be tested
twice. Tests with bare foot and sock were carried out at about +20 °C and 50 % RH.
The boots, a thin rubber and a winter boot, were tested at about +5 °C and 85 % RH.
The conditioning was done at 20±2 °C and 35±5 % RH. Air velocity was kept low (<0.3
m/s). Wet tests included simulation of sweating by supplying water to the foot skin at a
rate of 5 g/h/foot. Generally, 6 conditions were tested at most laboratories. The test
series can be used as a basis for applying for a project further on that eventually would
aim to suggest changes in existing European standard (EN 344) or propose a new
(international) standard on footwear thermal testing.
Relatively big inter-laboratory differences in measuring results were obtained. The
differences were smaller for total insulation values but could be more than 30 % for
local zones. Most of the differences would be explained by climatic conditions,
construction of foot, measuring principle a.o. More elaborate comparative tests under
different conditions and with more types of footwear need to be done. The effects of
differences in model construction etc. should be analysed further. For standard use it is
important to determine which zones should be included in the total insulation
calculation and which zones should be reported separately, e.g. sole area. The foot
construction, the conditions, measurements and calculations for wet tests should be
more clearly defined.
Eight laboratories were able to carry out tests. The foot models varied in sizes from 254
mm to 275 mm, representing boot sizes from 41 to 44. Six other laboratories were
interested but were not able to carry out the tests within this study. A database has been
created. New test results from other test laboratories and on other footwear can be added
later on. The test series were carried out under standardised conditions in each
laboratory. Ten (10) test conditions were recommended. All conditions had to be tested
twice. Tests with bare foot and sock were carried out at about +20 °C and 50 % RH.
The boots, a thin rubber and a winter boot, were tested at about +5 °C and 85 % RH.
The conditioning was done at 20±2 °C and 35±5 % RH. Air velocity was kept low (<0.3
m/s). Wet tests included simulation of sweating by supplying water to the foot skin at a
rate of 5 g/h/foot. Generally, 6 conditions were tested at most laboratories. The test
series can be used as a basis for applying for a project further on that eventually would
aim to suggest changes in existing European standard (EN 344) or propose a new
(international) standard on footwear thermal testing.
Relatively big inter-laboratory differences in measuring results were obtained. The
differences were smaller for total insulation values but could be more than 30 % for
local zones. Most of the differences would be explained by climatic conditions,
construction of foot, measuring principle a.o. More elaborate comparative tests under
different conditions and with more types of footwear need to be done. The effects of
differences in model construction etc. should be analysed further. For standard use it is
important to determine which zones should be included in the total insulation
calculation and which zones should be reported separately, e.g. sole area. The foot
construction, the conditions, measurements and calculations for wet tests should be
more clearly defined.
Department/s
Publishing year
2003
Language
English
Publication/Series
EAT report
Document type
Report
Publisher
Lund University
Topic
- Production Engineering, Human Work Science and Ergonomics
Keywords
- sweating simulation
- footwear
- standard test method
- moisture absorption
- moisture transport
- insulation
- cold protection
- thermal foot model
Status
Published
Report number
2003:01
Research group
- Thermal Environment Laboratory
ISBN/ISSN/Other
- ISSN: 1650-9773
- ISRN LUTMDN/TMAT-3019-SE