Auto Power Off - sauter SW 1000 Instruction Manual

☆ Hint: The system clock installed in the sound level meter was calibrated using a
reference clock with an average error of 2 ppm (maximum error: 3 ppm). The time
accuracy at room temperature is below 10 ppm (< 26 s in 30 days). The maximum
time error during internal tests at 25°C was approx 5–8 s.
approx. 2.16 s per day. If the temperature is 40°C, the value for the system clock
changes by –0.04 × (40–25)² = –9 ppm, which corresponds to a delay of approx. 0.78
s per day.
The maximum error (< 10 ppm) specified in the User Manual, can be calculated as
approx. 16°C of difference compared to the reference temperature of 25°C. There-
fore, the RTC error within 30 days at a temperature of 9°C to 41°C, i.e. ambient tem-
perature, can be maintained at 26 s. If the temperature range is exceeded, the actual
RTC error may be higher than the value specified in the User Manual.

4.4.6 Auto Power Off

keys <◄> and <►> to choose an option. Press <ENTER> to save the setting.
SW-BA-e-1710
The system clock accuracy may vary depending on
the temperature due to the lack of temperature
compensation. At the typical characteristics shown
in the figure, the basic frequency of the system
clock remained unchanged. Any increase or de-
crease of temperature causes a change in the sys-
tem clock frequency by approx. –0.04 ppm/°C².
Therefore, when the temperature is 0°C, the value
for the system clock changes by –0.04 × (0–25)²
= –25 ppm, which corresponds to a delay of
The sound level meter is provided with the Auto Power Off func-
tion, activated upon a drop of current consumption. If the sound
level meter remains in the Stop mode and no key is pressed for a
specific time, the device will switch off as per this setting. The
Auto Power Off function offers the following settings: 1 minute,
5 minutes, 10 minutes, 30 minutes, OFF Press the navigation
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