INFICON STM-100/MF Thin Film Deposition Monitor - Manual (Page 43)

SENSOR HEAD INSTALLATION
As a general rule the sensor head should not be installed closer than 10
inches to the evaporation source. This minimum distance will generally provide
adequate measurement sensitivity while reducing the possibility of the source
spattering small particles onto the sensor. Even small particles hitting the crystal
surface may cause the crystal to become unstable or stop oscillating completely.
The sensor should be shielded from the evaporant source by a shutter or other
means when evaporant material is being initially conditioned or out gassed.
Install the sensor so that the crystal opening is in a direct line with the
evaporation source and well within the evaporant stream. Ensure that the sensor
is not shadowed by mechanical structures within the vacuum system. The sensor
should be held mechanically stable by attaching it to a mounting bracket via the
rear #4-40 tapped holes.
Water Cooling
Microdot Coaxial Connector
#4-40 Tap -- 4 holes
Equally Spaced
on o0.731 B.C.
Figure 3.8: Head Mounting Dimensions.
Installing Water Lines
Bend the two sensor water lines into the desired position for connection to
the vacuum feedthrough. Take care not to crimp the lines. There are two
methods for attaching the water lines to the feedthrough.
The first is to silver solder or TIG weld the sensor and water lines together. To do
this first locate the final position of the sensing head and feedthrough. Trim the
1/4" water lines on the feedthrough to the desired length. Bend and fit the sensor
water lines as required. Cut the 1/8" water lines to length allowing 1/4" to 1/2" of
extra length to be inserted the 1/4" feedthrough water lines. Then braze, silver
solder, or TIG weld.
The second is to use Swagelok compression fittings. These are available from
Sycon as part number 022-001. These can also be purchased from Swagelok as
part number SS-300-6-2.
Sensor Installation
Water Lines
Page 3 - 9 INSTALLATION