Airvac 400 : l'avis d'Eddie Platts et de Roland Ranfft (Revues & Essais)

posté par Ed the Grocer (modérateur) , Paris, 13/04/22, 11:04

Trouvé dans une discussion de TZ UK datant de 2003 l'avis de deux pointures :

Eddie Platts :

"Another innovative case design from the factory of Ervin Piquerez-Fresand. The air was pumped out of the Airvac cases after assembly so that the movements ran in a vacuum. Easily identified by the logo on the case depitcting the air being withrawn from a bell-jar. Glycine used the vacuum case with great success in the 1960s. Interestingly, movements ran a few seonds faster in a vacuum and certainly in the Glycine watches, the inside case back was engraved with a warning to watch repairers to make allowance for this when casing the watch. Sadly, there doesn't appear to be any repairers equipped to reinstate the vacuum today and so this watch must be regarded as being a standard non-vacuum watch."

These watches will still function correctly without a vacuum in the case.

Eddie"

Et de Roland Ranfft :


"from present point of view, a vacuum in the case is nonsense. When these cases were designed, knowledge about diffusion of gasses (and liquids) through gasket materials wasn't as common as today. Only metal on metal sealings like the lead gaskets of the fifties are really gass tight. But air will still march through the crown gasket and the plastic crystal of such watches - not through gaps or cracks, but actually through the material.


"I guess it is not worth to be investigated - maybe weeks or months. The tiny helium atoms need just hours to equalize internal and external pressure, making helium valves necessary for professional divers watches. They prevent that the crystal is popped out when external preasure decreases.

Oxigen and nitrogen will diffuse much slowlier. But you'll get an idea of the speed, if you watch water vanishing out of a closed plastic bottle in reasonable short time. Imagine how much vapor is represented by some millilitres water.

Regards,
Roland Ranfft"

---
Ed the Grocer ancienne maison l'Epicier

Discussion complète:

• Jaquet-Girard Perfex Airvac 400 : la force du vide - Ed the Grocer (modérateur), 12/04/22, 14:50
  • Jaquet-Girard Perfex Airvac 400 : la force du vide - Gér@rd, 12/04/22, 17:41
    • Les brevets 317537, 321578 et 337462 Airvac 400 - Ed the Grocer (modérateur), 13/04/22, 09:32
  • Jaquet-Girard Perfex Airvac 400 : la force du vide - Bertrand, 12/04/22, 18:45
    • Jaquet-Girard Perfex Airvac 400 : la force du vide - Gw, 12/04/22, 23:20
      • Jaquet-Girard Perfex Airvac 400 : la force du vide - Bertrand, 12/04/22, 23:37
        • Jaquet-Girard Perfex Airvac 400 : la force du vide - Bertrand, 12/04/22, 23:40
        • Jaquet-Girard Perfex Airvac 400 : la force du vide - Gw, 13/04/22, 20:02
  • Airvac 400 : l'avis d'Eddie Platts et de Roland Ranfft - Ed the Grocer (modérateur), 13/04/22, 11:04
  • Des précisions de Joel de Toulouse sur le système Vacuum - Ed the Grocer (modérateur), 12/12/22, 15:41