JDC Electronic SA Porosimeter MK1 - Manuel (Page 2)

Developed and manufactured by:
JDC ELECTRONIC SA
Avenue des Sports 42
CH-1400 YVERDON-LES-BAINS
SWITZERLAND
P: +41 (24) 445 2121
F: +41 (24) 445 2123
Email: [email protected] Internet: www.jdc.ch
…SWISS PRECISION INSTRUMENTS
POROSIMETER JDC MK1
A professional instrument from JDC ELECTRONIC SA
PURPOSE OF THE DEVICE: Enable an air volume to go through a cloth in order to measure its
porosity.
APPLICATION: - Quick test of cloth porosity used for example in paraglider
manufacture.
- Measures a cloth degradation in order to warn the parapentist of
properties and security decrease of its canopy.
- Evaluation of the actual and resale value of second-hand
paragliders.
- Laboratory study of cloth wear (coating adherence, etc.).
PRINCIPLE: Measures the necessary time for 0.25 liter of air under
10 mbar pressure to go through 38.5cm
2
of cloth.
HOW TO USE IT: Plug the display module in and turn it on. The readout is automatically
reset at the beginning of each measure.
Pull up the rubber bellows by lifting up the plastic bar and locking the
lever on the metal ring.
Remove the magnetic disc, place the cloth to be tested on top of the
porosimeter avoiding folds and damaged spots and put back the
rubber magnetic ring. Press the lever, the readout is automatically
reset to zero at the beginning of the measure and counts in 1/10 of
second the necessary time for 0.25 liter of air to go through the cloth.
The measuring time varies from 2 to 3 seconds for a worn
paraglider's cloth and lasts 5 minutes or more for a new cloth.
MEASURE OF TWO LAYERS
SIMULTANEOUSLY:
The cells of some paragliders are closed by a net. This requires to
measure two layers simultaneously. This is possible with the JDC
MK1 porosimeter in the following manner:
Fold a portion of the extrados in order to have two superposed layers
that you set on the porosimeter, making sure there are no folds. For
little porous cloth, the result of the measure will be very close to the
one you would have with one layer only. For very porous cloth, the
result will be up to 10 % higher than with one layer. With two cloths of
different porosity, the resulting value will be the one of the less
porous cloth.
TECHNICAL SPECIFICATIONS: Dimension: diameter 150 x 230 mm
Weight: 2.4 kg (3.3 kg with the case)
Power supply: 2x AA batteries;
Accuracy: factory gauged for a repeatability of ± 2% with a 0.3 mm
diameter reference hole.
Remark: the repeatability with cloths is not as good as specified
above because it depends a lot on its setting (position,
traction, folds, etc
…).
Warranty: 2 years