PCB Piezotronics IMI SENSORS 622B01, Инструкция по установке и эксплуатации

Страница: 9 / 19

MS – Mine Safety Approved Sensors
TO – Temperature Output Sensor
Note : Not all sensors are available with the optional
prefixes. Contact the factory to discuss special
features that may be needed.
4.0 INSTALLATION OVERVIEW
When choosing a mounting method, consider closely both
the advantages and disadvantages of each technique.
Characteristics like location, ruggedness, amplitude range,
accessibility, temperature, and portability are extremely
critical. However, the most important and often
overlooked consideration is the effect the mounting
technique has on the high-frequency operating range of
the accelerometer.
Shown in Figure 4 are six possible mounting techniques
and their effects on the performance of a typical
piezoelectric accelerometer. (
Note: Not all of the
mounting methods may apply to your particular sensor. )
The mounting configurations and corresponding graph
demonstrate how the high-frequency response of the
accelerometer may be compromised as mass is added to
the system and/or the mounting stiffness is reduced.
Note:
The low-frequency response is unaffected by the
mounting technique. This roll-off behavior is typically fixed
by
the sensor’s built -in electronics. However, when
operating AC-coupled signal conditioners with readout
devices having an input impedance of less than one
megaohm, the low frequency range may be affected.
4.1 STANDARD STUD MOUNT
This mounting technique requires smooth, flat
contact surfaces for proper operation and is
recommended for permanent and/or secure
installations. Stud mounting is also recommended
when testing at high frequencies.
Note:
Do NOT attempt mounting on curved, rough,
or uneven surfaces, as the potential for misalignment
and limited contact surface may significantly reduce
the sensor’s upper operating frequency range.
STEP 1:
First, prepare a smooth, flat mounting
surface and then drill and tap a mounting hole in the
center of this area as shown in Figure 5.
A precision-machined mounting surface with a
minimum finish of 63 µin (0.0016 mm) is
recommended. (If it is not possible to properly prepare
the machine surface, consider using an adhesive
mounting pad as a possible alternative.) Inspect the
area, checking that there are no burrs or other foreign
particles interfering with the contact surface.
STEP 2:
Wipe clean the mounting surface and spread
on a light film of grease, oil, or similar coupling fluid
prior to installation. See Figure 6.
Adding a coupling fluid improves vibration
transmissibility by filling small voids in the mounting
surface and increasing the mounting stiffness. For