Table of Contents
Advertisement
20
Installation
RPM sensor – VIB 6.620 / VIB 6.622
The machine speed is measured by means of a non-contact inductive
RPM sensor. PRÜFTECHNIK offers two suitable sensors for different
installation types and switching frequencies:
- VIB 6.620 – non-flush installation; switching frequency < 300 Hz
- VIB 6.622 – flush installation; switching frequency < 1500 Hz.
The sensor is mounted near the measurement marks of the machine
shaft (e.g. threaded coupling or ring gear). For each revolution the
measurement marks generate an electrical pulse in the sensor. For
checking the function there is an LED on the sensor that goes out
with each induced pulse. The rotational speed is the pulse frequency
divided by the number of measurement marks on the shaft.
Measuring marks increase the measurement precision
The faster the shaft rotates and the more measurement marks are reg-
istered, the more precise is the measurement of the rotational speed.
The upper switching frequency of the sensor must not be exceeded.
For measuring low speeds (< 60 RPM) there must be at least two
measurement marks on the shaft. The number of meas urement marks
must be recorded in the installation report and taken into account in
the measurement configuration in the OMNITREND Center PC soft-
ware (context: measuring channel).
Installation
The RPM sensor is electrically insulated. You can install it on the
machine housing with a suitable mounting bracket. Make sure that
the setup is not affected by machine vibrations.
• Switch off the machine and secure it against restarting.
• Select a suitable location in the vicinity of the measurement marks.
The measurement mark should have a diameter of at least 10 mm.
The distance between the measurement mark and the sensor must
not exceed 8 mm (see illustration on next page).
Risk of injury from fragments!
Insufficient measuring distance may lead to contact of measurement
mark and sensor. Upon contact fragments may splinter and severely
injure persons.
• When adjusting the measurement distance, take into account any
radial shaft movement.
Measurement error due to EM interference
No electromagnetic fields with a frequency of 600 Hz are permitted in
the vicinity of the RPM sensor.
WARNING
NOTE
Advertisement
Table of Contents
