Instructions
37
Vibration offset “D”
Unit mm
Measuring range 0.001 - 1.999 mm
Resolution 0.001 mm
Accuracy ± (5% + 2)
Vibration frequency 10 Hz - 500 Hz
Measuring function Peak-peak (p-p)
Comparison Values
For evaluation of machines and accessories, the directives ISO 2372 and VDI 2056 differentiate between 4 classes.
In these classes, the vibration limits are specied (in mm/s).
The following device groups are classied:
Group K Small machines with electric motors up to 15 kW output
Group M Medium-sized machines with electric motors > 15 kW to 75 kW output, no special foundation
Group G Large machines with heavy foundation
Group T High-performance machines with special foundation
Group K Group M Group G Group T
Good 0 – 0.71 mm/s 0 – 1.12 mm/s 0 – 1.8 mm/s 0 – 2.8 mm/s
Acceptable 0.72 – 1.8 mm/s 1.13 – 2.8 mm/s 1.81 – 4.5 mm/s 2.8 – 7.10 mm/s
Still admissible 1.81 – 4.5 mm/s 2.81 – 7.1 mm/s 4.51 – 11.2 mm/s 7.11 – 18 mm/s
Dangerous > 4.5 mm/s > 7.1 mm/s > 11.2 mm/s > 18 mm/s
In directive ISO 2373, mechanical vibrations of circumfering electrical machines with axis heights of 80 to 400 mm, the
measurement and evaluation of the vibration strength are indicated.
Quality degree
Rotating speed
(rpm)
Axis height in mm
max. vibration strength in mm/s
80 - <132 mm 132 - <225 mm 225 - 400 mm
N (Normal) 600 - 3600 1.8 2.8 4.5
R (Good) 600 - 1800 0.71 1.12 1.8
1800 - 3600 1.12 1.8 2.8
S (Special) 600 - 1800 0.45 0.71 1.12
1800 - 3600 0.71 1.12 1.8