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User’s Manual
9
6.4.2
Operation LED
The operation LED is always blinking.
LED State
Meaning
Off
Instrument is in
Idle
mode.
1-blink/second
Instrument is in
Active or Auto-Rec
mode, but is not actively recording.
2-blinks/second
Instrument is actively recording.
1-blink/second
(off-beat)
Instrument is presently communicating with a server via
WiFi™.
4-blinks/second
Battery is low. Recharge as soon as possible. If the battery level becomes critical
the instrument will go to
Idle
mode (LED-off) in order to safeguard the battery
against over-discharge as much as possible.
Table 3
6.5
Acceleration Sensor and Signal Processing
6.5.1
Measurement
The 3-axis MEMS accelerometer inside the
ABC-Mems
accurately measures static (DC) and dynamic
(AC) acceleration signals with an adjustable sampling rate of up to 4 kHz.
Velocities are calculated in real-time from the acceleration sensor.
The accelerometer’s dynamic range is +-8g.
When measuring accelerations an adjustable-frequency high-pass filter can be added to the
measurement path. The high-pass filter is required to measure RMS vibration levels. Otherwise the
measured RMS levels would be biased by the DC component. On the other hand, inclination
measurements require the measurement of the DC component, so DO NOT use the high-pass filter for
inclinations.
When measuring velocities, a high-pass filter is automatically placed in the signal path. The cutoff
frequency is adjustable, and has an impact on velocity noise.
The instrument’s power consumption is proportional to the sampling rate, and dependent upon whether
the instrument is set to record raw signals or statistics.