Assembling The I-Mag Sensor - MKS HPS 937A Series Owner's Operation And Maintenance Manual

Assembling the I-MAG Sensor

Wear gloves and assemble with clean tools.
Roll the sensor body on a flat surface and, looking down the port,
1
check the anode
and centered with the sensor body
2 Install the ground shield
tweezers. Make sure that the ground
shield drops into the locating collar
3 Slide the small ceramic spacer
the small end of the ground shield
4 Check that the leaf spring
contact the base of the cathode
shown to the right. If not, remove the
small ceramic spacer and the ground
shield , and gently bend the leaf spring
towards the anode
the ground shield and ceramic spacer .
5 Slide the cathode
,and the large ceramic spacer
3
place. The grid washer has a concave shape. Refer to the figures to
see its installation orientation.
Insert the small end of the compression spring
6
body .
7
Using your thumbs, push the larger end of the spring into the sensor
7
body until it is contained within the tube's inside diameter.
8 Using the smooth-jaw, needle-nose pliers, work the compression
spring down into the sensor body until it is fully seated in the formed
groove.
9 Inspect the ground shield
are centered with respect to the anode
10 If adjustment is needed, gently reposition the grid washer/cathode
assembly, taking care not to scratch the grid washer .
We suggest you measure the resistance between the ion current feedthrough
pin and the grid washer
13
with the cathode . The measurement should indicate a short circuit
4
between them. There should be an open circuit between the ion current
feedthrough pin 13 and both the high voltage feedthrough pin
body .
7
for any radial runout motion. It should be straight
8
for proper operation.
7
using
6
.
11
over
5
6 .
will
9
4 as
and then replace
8
4 , the grid washer
into
2
and the grid washer
6
8
to verify that the leaf spring
3
937A Multi-Sensor System
Leaf spring in
contact with
cathode
into the sensor
1
to verify they
3
.
is in contact
9
and sensor
10
A.5