CEMB USA N100 - Manual (Page 35)

Balancing function 6 - 1
Chapter 6
Balancing function
Before proceeding with more in-depth analysis, operators may sometimes need to detect
the rotation velocity of one or more of the shafts with a high degree of precision.
The N100 instrument has a precise tachometer function, accessible from the main control
panel, capable of measuring velocity of up to 60,000 RPM (1000 Hz).
The following instructions must be complied with for correct rotation velocity
measurement:
- apply a suitable reflecting sticker on the rotating body as a point of reference (0°).
− connect the photocell to the N100 instrument and position it at a distance of
between 50 and 400 mm from the rotating body. Slowly turn the rotating body (if
possible by hand, otherwise as slowly as possible) and check that the LED
positioned on the back of the photocell only lights up once per turn, when the ray
of light lights up the reference mark. If that is not the case, move the photocell
closer to or further away from the piece or tilt it away from the surface.
Warning:
Take great care when positioning the photocell: as the rotating body requires
manual intervention, make sure that it is still and cannot be started up accidentally.
If the rotating body cannot be rotated by hand when positioning the photocell, it
should be positioned in points in which the LED is visible without having to get
too close to the moving bodies.
Measurement settings
The unit of measurement is the only element that must be set before proceeding with the
measurement of angular velocity.
Press to display this parameter as a negative
value, whilst the and arrows can be used to change from Hertz (Hz) to revs
per minute (RPM).
Press to confirm the new value; whilst quits the setting without
changing the existing values.