[ Aller au nouveau Forum ]

Re: A ma connaissance,

[ chronomania.net - Les archives de l'ancien forum ]

écrit par Dominique le 15 novembre 2003 11:02:37:

en réponse à: A ma connaissance, écrit par domi38 le 15 novembre 2003 09:56:58:

Bonjour, à ma connaissance, c'est en 1964 que la Nasa a testé plusieurs chonographes pour en choisir un. Voici la liste des tests passés (compilés par Chuck Maddox)
To be flight-quelified by NASA for all manned missions the Omega Speedmaster Professional Chronograph successfully passed 11 different tests numerious times...
1 High Temperature

48 hours at a temperature of 160° F (71°C) followed by 30 minutes at 200F (93C). This under a pressure of 5.5 psia (0.35 atm) and relative humidity not exceeding 15%
2. Low temperature

Four hours at a temperature of 0F (-18C)
3. Temperature pressure

Chamber pressure maximun of 1.47 x 10exp-5 psia (10exp-6 atm) with temperature raised to 160F (71C). The temperature shall then be lowered to 0°F (-18C) in 45 minutes and raised again to 160F in 45 minutes. Fifteem more such cycles shall be completed.
4. Relative humidity

A total time of 240 hours at tempeartures varying between 68F and 160F (20C and 71C) in a relative humidity of at least 95%. The steam used must have a pH value between 6.5 and 7.5
5. Oxygen atmosphere

The test item shall be placed in an atmosphere of 100% oxygen at a pressure of 5.5 psia (0.35atm) for 48 hours. Performance outside of specification tolerance, visible burning, creation of toxic gases, obnoxious odours or deterioration of seals and lubricants shall constitute a failure to pass this test. The ambient temperature shall be maintained at 160°F (71°C)
6. Shock

Six shocks of 40g's each 11 miliseconds in duration, in six different directions.
7. Acceleration

The equipment shall be accelerated linearly from 1g to 7.25 g within 333 seconds, along an axis parallel to the longitudinal spacecraft axis.
8. Decompression

Ninety minutes in a vacuum of 1.47 x 10E-5 psia (10 E-6 atm) at a temperature of 160F (71C) and 30 minutes at a 200F (93C)
9. High Pressure

The equipment to be subjected to a pressure of 23.5 psia (1.6 atm) for a minimum period of one hour.
10. Vibration

Three cycles of 30 minutes (lateral, horizontal, vertical, the frequency varying from 5 to 2000 cps and back to 5 cps in 15 minutes. Average acceleration per impuls must be at least 8.8g.
11. Acoustic noise

130 dB over a frequency range from 40 to 10000 HZ, duration 30 minutes.

Il semble bien qu'à l'issue de ces tests la Spedmaster était la seule encore en bon état de marche.... Elle a d'ailleurs été soumise de nouveau à ces tests en 1978 et elle a conservé sa qualification. Alors à quoi cela tient-il: qualité de fabrication, simplicité, robustesse? Sans doute tout celà et cette somme de qualités a assuré sa qualification et maintenant son "aura"....
Amicalement.


Réponses:

[ chronomania.net - Les archives de l'ancien forum ]