General Tools and Instruments VM8205SD User Manual
Page 7
The meter can measure two vibration-related parameters (acceleration and velocity) and
show readings of each one in any of three units. Acceleration can be measured and
displayed (using the term “ACC”) in the metric unit m/s
2
, the metric unit “g” (gravitational
force) or the English unit ft/s
2
. Velocity can be measured and displayed (using the term
“VEL”) the in the metric unit mm/s, the metric unit cm/s or the English unit inch/s.
4. To select the measurement parameter and its units, press the REC/ENTER button
(which has the word “Unit” stenciled below it). Doing so cycles through the six
parameters and units in the following order:
• ACC in m/s
2
• ACC in g
• VEL in mm/s
• VEL in cm/s
• ACC in ft/s
2
• VEL in inch/s
Pressing the REC/ENTER button when VEL in inch/s is displayed returns the display to
ACC in m/s
2
. Releasing the button saves the displayed parameter/unit as the default.
For most industrial vibration measurement applications, use an acceleration setting.
Pressing the FUNC./HOLD/NEXT button repeatedly cycles through the three functions that
can be performed on measured values. The meter can:
• Show the root mean square (RMS) value of measured acceleration or velocity readings
(this is the typical function performed on acceleration and velocity measurements)
• Measure the peak value in a series of measurements (the display shows “PEAK”)
• Update and hold the peak value (the display shows “Max HOLD”). To clear a previously
stored peak value, press the LOGGER ▲ button and hold it for at least five seconds.
5. To choose the function to be applied to measured values, press the
FUNC./HOLD/NEXT button until the text corresponding to the desired function appears on
the display. Then release the button. Doing so makes the selected function the default
until the FUNC./HOLD/NEXT button is pressed again.
The following tables correlate the severity of a machine’s vibration (good, acceptable,
still permissible and dangerous) with a range of values for each of the four machinery
classifications recognized by ISO2372 and VDI 2056.
7
Small machines, especially production
electrical motors of up to 15 kW
(Group K)
Good
0 to 0.71 mm/s
Acceptable
0.72 to 1.80 mm/s
Still permissible
1.81 to 4.5 mm/s
Dangerous
> 4.5 mm/s
Medium sized machines, especially
electrical motors with 15 up to 75 kW
output, without special foundations
( Group M )
Good
0 to 1.12 mm/s
Acceptable
1.13 to 2.80 mm/s
Still permissible
2.81 to 7.1 mm/s
Dangerous
> 7.1 mm/s