Order values are frequency-selective vibration values. The frequency of the bandpass filter is measured at the digital input of an M302 / M312. The bandpass filter can also be set at multiples or fractions (orders) of this frequency.
Signal input
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Selects the physical input and the gain of the USB device for the analog signal and the digital input for frequency measurement.
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Measurand and unit
The connected sensor determines the available options. Velocity and displacement are calculated from acceleration by integration (VM-PLOT+ only).
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Characteristic
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After passing the bandpass filters a sine-wave signal will remain. The following characteristics can be measured to characterize it:
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Peak value
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Magnitude
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RMS
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Root mean square value
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Phase angle
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Phase shift between the sine-wave magnitude and the low-high slope of the digital rpm signal
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Order
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Selects multiples or fractions of the rotation frequency for bandpass filtering.
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Examples:
Rotation frequency
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1 : 1
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Triple rotation frequency
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3 : 1
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Half rotation frequency
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1 : 2
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13/5 rotation frequency
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13 : 5
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Minimum speed
The M312 capable of detecting down to 6 1/min. However, it may take up to 10 seconds to detect standstill. To shorten this detection time you may increase the minimum speed value. For example at 30 1/min detection will be finished after 2 second. Frequencies below 30 1/min will then be suppressed.
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Suppress noise
An additional filter can be used to suppress interfering signals apart from the rotation frequency. In the selection field the bandwith of the filter can be specified or the filter can be switched off.
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