Premio Computer Apollo/Shadowhawk - Manual (Page 108)

Technical Reference
85
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 Mean Time Between Failures (MTBF) data is calculated from predicted data at 55 ºC. The
MTBF calculations for the boards are as follows:
• D845HV board MTBF: 147370.4687 hours
• D845WN board MTBF: 126077.3308 hours
2.14 Environmental
Table 54 lists the environmental specifications for the D845HV and D845WN boards.
Table 54. D845HV/D845WN Board Environmental Specifications
Parameter Specification
Temperature
Non-Operating -40 °C to +70 °C
Operating 0 °C to +55 °C
Shock
Unpackaged 50 g trapezoidal waveform
Velocity change of 170 inches/second
Packaged Half sine 2 millisecond
Product Weight (pounds) Free Fall (inches) Velocity Change (inches/sec)
<20 36 167
21-40 30 152
41-80 24 136
81-100 18 118
Vibration
Unpackaged 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)
Packaged 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