Vibration Comparator Frequently Asked Questions

The measurement modes of the vibration comparator VC-2100 include 4 types: RMS / PEAK / MAXHOLD / PEAK HOLD, which are displayed on the screen by switching. The comparison is made against the values on this display screen (the measurement mode being displayed). Furthermore, it is possible to make the measurement modes on the display screen and the comparator's measurement modes independent of each other.
Each measurement mode can have frequency band limitations (bandpass settings). For operation, please refer to the simplified operation manual A BAND setting menu.

Measurement Mode

The overview of each measurement mode is as follows.

(1) RMS (Root Mean Square)

Displays the maximum effective value over a period of 0.5 seconds. Measurements are repeated over a measurement time of 0.5 seconds.

PEAK

Displays the maximum absolute value of the time axis waveform over a duration of 0.5 seconds. Measurements are repeated over a measurement time of 0.5 seconds.

MAX HOLD

It displays the maximum effective value during the measurement time. In MAX HOLD mode, the vibration display value is held, but the bar graph is not held. Additionally, to release the max hold value, press the reset key (RST) or input a set signal from the terminal block on the back.

PEAK HOLD

It retains the maximum peak value of the absolute value during the measurement time. During peak hold, the vibration value is held, but the bar graph is not held. To release the peak hold value, press the reset key (RST) or input a reset signal from the terminal block on the back.

Comparison function

For the measurement modes (1) to (4) mentioned above, there are both manual operation and automatic operation modes.

(1) Manual Driving (MANU Driving)

• In the above measurement modes (1) RMS and (2) PEAK, the maximum value is measured repeatedly every 0.5 seconds as shown in the figure below, and the maximum value is updated on the display. It also checks whether this value exceeds the set threshold. Once a value is judged as NG (not good), the comparison output will be maintained until it is reset. (The NG judgment will not turn OFF unless it is reset, even if the display drops below the set value.)

  Reset → 0.5 second measurement → Maximum value display → 0.5 second measurement → Maximum value display update... (End of first judgment) → Reset (Start of second judgment) ...

  It will be repeated measurements/judgments.



• In the above measurement modes (3) MAX HOLD and (4) PEAK HOLD, there is no measurement time frame like the 0.5 seconds mentioned in item 1; instead, values are judged instantaneously. Once a value is determined to be over the threshold, the judgment of NG (not good) is maintained until it is reset.

  Reset → MAX HOLD / PEAK HOLD (end of the first judgment) → Reset (start of the second judgment) ...

• Temporary pause, reset
  In manual operation, temporary measurement pause is possible by pressing the ENT key. (There is no input function from the terminal block)
  The screen will display the word PAUS. Pressing the ENT key again will release it.

  To reset, press the 'RST' button on the front panel or input the reset from the terminal block on the back panel.

autonomous driving

The ON/OFF of the GATE signal can control "measure / stop measuring". (The gate signal is input from the terminal block on the rear panel)
The judgment will be held as NG until it is reset, just like in manual operation, once it is judged as NG. Please use the comparator with GATE in the following sequence.

Reset → GATE on (measurement/judgment) → GATE off (reading judgment) → Reset (start of second judgment) ...

• In the above measurement modes (1) RMS and (2) PEAK, the measurement values will be as shown in the figure below, depending on the timing of the gate.

  

  ・When the GATE time is less than 0.5 seconds: Displays the maximum value within the gate time when GATE is OFF
  ・When the GATE time is 0.5 seconds or more: Sequentially displays the maximum value at 0.5 second intervals
  ・Comparison judgment is made against the displayed value.

• In the above measurement modes (3) MAX HOLD and (4) PEAK HOLD, the measurement time does not have the 0.5 second measurement frame like (1) RMS and (2) PEAK, and it sequentially determines the maximum value based on the instantaneous value.
  The comparator retains the judgment ON once it determines NG until it is reset.

  Reset → MAX HOLD / PEAK HOLD (end of first assessment) → Reset (start of second assessment) ...