POROSIMETER with carrying case

Skywatch MK1 Porosimeter

The JDC Skywatch MK1 Porosimeter is an easy-to-use, reliable, and very precise porosimeter to measure the porosity of fabrics that is now used and appreciated world wide. The porosity can be calculated by measuring the time it takes for 0.25 liters of air under 10mbar pressure to go through 38.5 cm2 of cloth. The result is given in seconds and can vary from a few seconds (coating very degraded), to more than 1000 seconds for the finest current fabrics. The MK2 is frequently used by cloth manufacturers, free flight schools/shops, paragliding and hang-gliding manufacturer, ballooning, and paper manufacturers.


  • Quick test of cloth porosity used in paragliding, spinnaker sails, and hot air balloons
  • Measure cloth degradation in wings and sails for safety reasons
  • Evaluation of the present and resale value of second-hand paragliders and sails
  • Laboratory study of cloth wear (coating adherence, etc.)

Kit includes:

  • Porosimeter
  • Time Display
  • Cable to connect porosimeter to time display
  • Approximate dimension: 8 pounds,7 x 7 x 10 inches


  • Powered by 2 AA batteries
  • Two year warranty

Technical specifications

The measuring pressure of the MK1 is 100 mm of water (10 mbar or 10 hPa). Result is given in seconds (necessary time for 0.25 liter of air to go through 38.5 cm2 of fabric under a pressure of 10 mbar.

Industry standard #1 (liter per m2 per min) (pressure of 200 mm of water)
= 5400 / time displayed on the MK1
Industry standard #2 (cm3 per cm2 per sec) (pressure of 200 mm of water)
= 9 / time displayed on the MK1

Accuracy - factory gauged for a repeatability of +/-2% with a 0.3 mm diameter reference hole. Repeatability with cloth is not as good as specified because it depends a lot on its setting (position, traction, folds, etc).