Doc# 0296-0018 • REV R (July 2017) Page 43 of 61
is usually a pancake coil in the end of cylindrical tube, that can be mounted close to the mov-
ing part. Excitaon is very high frequency, about 240,000 Hz for detecon of small gap
changes (as low as 1 micrometer [40 milli-inch] at 0.5 Hz.
Velocity Sensor
Used primarily in handheld probes, providing informaon for vibraon monitoring and bal-
ancing of rotang machinery. The basic velocity pickup is a magnet (as a seismic mass) sus-
pended on a spring which moves through a coil of wire.
Accelerometer
Work well over a very wide range of frequencies (1 to 20,000 Hz) and work best for high
frequencies where acceleraon is large. Used in applicaons such the passage of
turbine blades, which may be one hun- dred mes the sha rotaon, or the meshing of
gears or ball/roller bearings, which may be many mes the sha rotaons per minute. Other
advantages include their small size, light weight, good temperature stability and moderate
price. Accelerometers develop a voltage from a piezoelectric crystal that has a mass
mounted upon it. When the mass xed to the crystal vibrates from the moon of the
device upon which it is aached, the crystal generates a voltage proporonal to the force
applied by the mass as it vibrates with the machinery.
Operang Procedures
Step 1. Make sure that the TTS is OFF.
Step 2. Make sure that the amplitude knob is turned completely counter clockwise.
Step 3. The Transducer Under Test should already be mounted on the Reference Accelerometer. If it is
not, go to Chapter 3 for installaon instrucons.
Step 4. Make sure that you have the TUT Test data handy for reference during the Test Procedures.
Step 5. Turn the Power to ON.
Step 6. The TTS cycles through the self-test.
• The TTS is automacally checking the RAM and ROM.
• The Baery Check Mode screen appears if the tests are successful. (See Fig. 5-1)
FIG. 5-2 BATTERY CHECK MODE SCREEN
To Next Page
Loading...
Need help?
General
