7 mtbf – Kontron KTA55-pITX User Manual
Page 14
KTD-S0031-E Page
10 Specifications
KTA55/pITX User's Guide
Humidity
³
Operating:
10% to 90% (non condensing)
³
Non operating:
5% to 95% (non condensing)
3.7
MTBF
The following MTBF (Mean Time Between Failure) values were calculated using a combination of manufac-
turer’s test data, if the data was available, and a Bellcore calculation for the remaining parts. The Bellcore
calculation used is 'method 1 case 1'. In that particular method the components are assumed to be
operating at a 50% stress level in a 40°C ambient environment and the system is assumed to have not been
burned in. Manufacturer’s data has been used wherever possible. The manufacturer’s data, when used, is
specified at 50°C, so in that sense the following results are slightly conservative. The MTBF values shown
below are for a 40°C in an office or telecommunications environment. Higher temperatures and other envi-
ronmental stresses (extreme altitude, vibration, salt water exposure, etc.) cause lower MTBF values.
³
System MTBF (hours): 252839
Note: Fans usually shipped with KONTRON Technology A/S products have 50.000-hour typical operating life. The above esti-
mation assumes no fan but a passive heat sinking arrangement. Estimated RTC battery life (as opposed to battery failures)
is not included in the MTBF calculation. The RTC battery lifetime has to be considered separately. Battery life depends on
both temperature and operating conditions. When the KONTRON unit has external power; the only battery drain is from
leakage paths.