T-H Example: Difference between revisions

From ReliaWiki
Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
<noinclude>{{Banner_ALTA_Examples}}
<noinclude>{{Banner_ALTA_Examples}}
</noinclude>The following data were collected after testing twelve electronic devices at different temperature and humidity conditions:
</noinclude>The following data were collected after testing twelve electronic devices at different temperature and humidity conditions:
<br>
 
<br>
[[Image:ex1chp9.png|center|400px|]]
[[Image:ex1chp9.png|center|400px|]]
<br>
 
<br>
Using ALTA, the following results were obtained:  
Using ALTA, the following results were obtained:  


<br>
::<math>\begin{align}
::<math>\begin{align}
  \widehat{\beta }=\ & 5.874395 \\  
  \widehat{\beta }=\ & 5.874395 \\  
Line 18: Line 15:
  \widehat{\phi}=\ & 5630.329851   
  \widehat{\phi}=\ & 5630.329851   
\end{align}</math>
\end{align}</math>


A probability plot for the entered data is shown next.
A probability plot for the entered data is shown next.


[[Image:ALTA9probabilityplot.gif|center|600px|Probability plots at the tested combinations.]]
[[Image:ALTA9probabilityplot.gif|center|600px|Probability plots at the tested combinations.]]


Note that three lines are plotted because there are three combinations of stresses, namely, (398K, 0.4), (378K, 0.8) and (378K, 0.4).   
Note that three lines are plotted because there are three combinations of stresses, namely, (398K, 0.4), (378K, 0.8) and (378K, 0.4).   


Given the use stress levels, time estimates can be obtained for a specified probability. A Life vs. Stress plot can be obtained if one of the stresses is kept constant. For example, the following picture shows a Life vs. Temperature plot at a constant humidity of 0.4.
Given the use stress levels, time estimates can be obtained for a specified probability. A Life vs. Stress plot can be obtained if one of the stresses is kept constant. For example, the following picture shows a Life vs. Temperature plot at a constant humidity of 0.4.


[[Image:ALTA9stressplot.gif|center|600px|Life vs. Temperature plot with humidity fixed at 0.4.]]
[[Image:ALTA9stressplot.gif|center|600px|Life vs. Temperature plot with humidity fixed at 0.4.]]

Revision as of 07:42, 7 August 2012

ALTA Examples Banner.png


New format available! This reference is now available in a new format that offers faster page load, improved display for calculations and images and more targeted search.

As of January 2024, this Reliawiki page will not continue to be updated. Please update all links and bookmarks to the latest references at ALTA examples and ALTA reference examples.




The following data were collected after testing twelve electronic devices at different temperature and humidity conditions:

Ex1chp9.png

Using ALTA, the following results were obtained:

[math]\displaystyle{ \begin{align} \widehat{\beta }=\ & 5.874395 \\ & & \\ \widehat{A}=\ & 0.000060 \\ & & \\ \widehat{b}=\ & 0.280599 \\ & & \\ \widehat{\phi}=\ & 5630.329851 \end{align} }[/math]

A probability plot for the entered data is shown next.

Probability plots at the tested combinations.

Note that three lines are plotted because there are three combinations of stresses, namely, (398K, 0.4), (378K, 0.8) and (378K, 0.4).

Given the use stress levels, time estimates can be obtained for a specified probability. A Life vs. Stress plot can be obtained if one of the stresses is kept constant. For example, the following picture shows a Life vs. Temperature plot at a constant humidity of 0.4.

Life vs. Temperature plot with humidity fixed at 0.4.