Digi-Vibro Meter

Digi-Shock Meter

Looseness Meter Model 6105 is a measuring instrument specially developed for the purpose of measuring quantitatively the degree of looseness of a rotating bar of a large scale motor while its being subjected to a temporary maintenance in factories or plants. Judgment is made by observing amount of responding vibratory acceleration against the shock pulse applied.


  • A degree of the looseness of a tightened body can be got quantitatively in high a0ccuracy.
  • Small and handy. Excellent mobility throughout actual spots.
  • Judgment is made by both lamp and buzzer. The judgment can be conducted instantaneously from one object to another without seeing the displayed valued visually.
  • Because the starting button is mounted on the pulse hammer, an immediate and simple starting can be made.
  • A specially designed printer is prepared and is supplied optionally, for the recording of data measured.


When a knock is made to a tightened portion where a looseness might no doubt take place, a resonant vibration generates at that knocked portion. Such resonant vibration is changing in proportion with the degree of looseness as per Figures 3, 4 and 5.

On the other hand, a responding signal is also changing in proportion with hammering strength. In order to eliminate unnecessary effects to be brought about from the hammering strength, the conversion is made to produce the responding signal exactly corresponding to the unit strength of the hammering. After that, the final value got as a result of averaging 6 actually measures values is processed on a built-in microcomputer for the display on the digital display window and for the lighting of one of the 3 signal lamps.

The larger the amount of looseness, the larger the amount of responding signal against the same hammering strength. The amount of looseness is represented by the following formula:

Amount of looseness per unit strength(L) = Amount of responding vibration / Amount of hammering.


Fig. 6 shows the change in the looseness of the rotating bar of the motor during the period of 15 years. The judgment was made on the following three criteria of the looseness:

ACCEPTABLE: Lower than 0.3
  CAUTIOUS: Between 0.3 to 1.0
  NON ACCEPTABLE: Larger than 1.0
Measurement of the looseness
of the bar of the motor.
Hammering Direction




Main System of Looseness Meter, Model-6105 1 set
Acceleration Detector, Model-2304A 1 ea.
Contact Pin for the above 1 ea.
Low-Noise Cable, Model LNC-1A-3 for the above 1 ea.
Pulse Hammer, Model-2340 1 ea.
Cable for the above, 3m long. 1 ea.
Dry Battery, UM-1 1 ea.
Operation Manual 1 ea.
Power Unit with Printer 1 ea.


Main System 202W x 120H x 235D mm, approx. 3Kg.
Acceleration Detector   14mm dia. x 119 mm L (complete with Pin), approx. 630g.
Pulse Hammer   110H x 160L (Length of the Handle), approx. 155g.


POWER UNIT complete with PRINTER:
Dimension 154W x 64H x 159D mm
Weight   approx. 900g.


Machine that can connect to personal computer:
Loose Meter, Model-6105A
Connectable to personal computer via RS-232C interface.
Data acquisition software (for use with WINDOWS) provided.