INFICON Front Load Single Sensor - Manual (Page 72)

4 - 8
PN
07
4-
15
6N
Front Load Single and Dual Sensors Operating Manual
4.3.4 Replacing the Finger Spring
The finger spring (PN 750-171-P1) that retains the crystal holder in the sensor head
cavity should be replaced when the crystal holder is no longer being held securely
in the sensor head cavity, or after approximately 4000 crystal holder extractions.
NOTE: The actual number of crystal holder extractions before the retention force
is significantly reduced will vary based on process conditions.
Proceed as follows to replace the finger spring.
1 Extract the crystal holder. (Refer to section 4.2 on page 4-2 ).
2 Remove the finger spring with a pair of tweezers. (See Figure 4-7 .)
3 Insert the new finger spring, allowing it to expand and conform to the inner
diameter of the sensor assembly as shown in
Figure 4-7 .
NOTE: The finger springs are formed and heat treated to a diameter that is
larger than the diameter of its groove to aid in assembly and retention.
4 Verify that the finger spring is contained in the groove, by running a finger along
the inner lip of the sensor assembly, and verify that the finger spring has not
overlapped onto itself. This will ensure that the finger spring will not be
damaged during crystal holder installation.
5 Insert the crystal holder.
Figure 4-7 Finger spring replacement
Finger Spring
(PN 750-171-P1)
Sensor Body:
Standard: 750-207-G1
Right Angle: 750-209-G1
Dual: 750-208-G1