2.13 Reliability
The Mean Time Between Failures (MTBF) prediction is calculated using component and
subassembly random failure rates. The calculation is based on the Bellcore Reliability Prediction
Procedure, TR-NWT-000332, Issue 4, September 1991. The MTBF prediction is used to estimate
repair rates and spare parts requirements.
The MTBF data is calculated from predicted data at 55 ºC. The Desktop Board D845GLVA
MTBF is 146,760 hours.
2.14 Environmental
Table 41 lists the environmental specifications for the Desktop Board D845GLVA.
Table 41.
Desktop Board D845GLVA Environmental Specifications
Parameter
Temperature
Non-Operating
Operating
Shock
Unpackaged
Packaged
Vibration
Unpackaged
Packaged
Specification
-40 °C to +70 °C
0 °C to +55 °C
50 g trapezoidal waveform
Velocity change of 170 inches/second
Half sine 2 millisecond
Product Weight (pounds)
<20
21-40
41-80
81-100
5 Hz to 20 Hz: 0.01 g² Hz sloping up to 0.02 g² Hz
20 Hz to 500 Hz: 0.02 g² Hz (flat)
10 Hz to 40 Hz: 0.015 g² Hz (flat)
40 Hz to 500 Hz: 0.015 g² Hz sloping down to 0.00015 g² Hz
Free Fall (inches)
Velocity Change (inches/sec)
36
167
30
152
24
136
18
118
Technical Reference
67