Kistler-Morse KM ultrawave - Manual (Page 72)

example 1, if a large signal change is detected that falls outside of the window, the UltraWave Series
immediately moves the location of the reference median to that point. This allows the UltraWave Series
to adjust quickly to rapid material movement.
• Enable turns the filter function on and off. The default is On.
• Delta Change determines the magnitude of change from the old reference median to the new reference
median, for change triggered by the qualify parameter. In example 2 in Figure 26 , the UltraWave Series
moves the reference median 80% of the distance from the old median to the last signal (which triggered
the change), based on a Delta Change of 80%. A value of 100% sets the new median to the last signal
value; a value of 50% sets the new median halfway between the old median and the last signal value.
Note that Delta Change does not affect the change caused by a signal falling outside of the Step
window, as shown in example 1 in Figure 26.
Note: The Sentry DSP algorithm dampens the response rate of the UltraWave Series. For demonstration/test
purposes set Enable to Off.
Figure 26: Sentry DSP Function Examples
74 noise (consult Kistler-Morse before Modifying!)
The Noise function reduces the effect of extraneous noises that may confuse the signal processor. This menu
sets up the noise routine algorithm. The algorithm is activated when the measured noise level (Monitor) exceeds
the noise threshold level (Threshold). Noise has seven submenus:
• Monitor is used to monitor the current noise level. This value is calculated by capturing the voltage level
at the current maximum TVG gain prior to the transmit burst. Monitor has a range between 0% (0 ADC
counts) and 100% (2047 ADC counts).
• Meas Dev Ratio is used to monitor the current deviation ratio. This number is calculated by dividing the
listen deviation value (Listen Deviation) by the transmit deviation value.
• Threshold is a noise threshold. Measured noise levels (Monitor) that are above this threshold cause the
noise algorithm to be switched on. At this point, all level measurements are frozen and are only updated
when the noise algorithm qualifies a valid target or the noise level falls below Threshold. The default for
Threshold is 100.0%. When Threshold is 100.0%, the noise algorithm is turned off.
• Std Dev Ratio is a deviation ratio threshold. Any measured deviation ratios (Meas Dev Ratio) larger than
Std Dev Ratio indicate a high confidence level that the mean transmit target value is the actual target.
When Meas Dev Ratio exceeds Std Dev Ratio the UltraWave Series uses the mean target value to
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