SRC Forum - Message Replies
Forum: Reliability & Maintainability Questions and Answers
Topic: Reliability & Maintainability Questions and Answers
Topic Posted by: Reliability & Maintainability Forum
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Posted by: Jean-Marie CLOAREC
Date posted: Fri Oct 25 10:11:26 US/Eastern 2002
Subject: Negative temperature
How calculate failure rate when ambiant temperature is negative. MIL HDBK 217 + RDF + ... are based on temperature from 0°C to ... but when temperature is for example -25°C ?
Subject: Negative Temps
Reply Posted by: Joe Dzekevich
Date Posted: Tue Oct 29 12:52:09 US/Eastern 2002
You must use an absolute temp scale. If you look into most standards, they use degrees K for their Pi-T formulas. Hopefully the reliability prediction softeare you are using can handle a negative number if it requires temps in centrigrade. Otherwise, you must calculate Pi-T yourself and then overide it in your program.