1 physical installation – INFICON Composer Gas Concentration Controller User Manual
Page 28
1 - 10
IP
N 07
4-
28
9L
Composer Operating Manual
1.10.1 Physical Installation
The Transducer is connected to the Reactor’s delivery tubing with Cajon™
VCR-4 fittings. Although a vertical orientation is shown, there is no restriction
on mounting orientation. It is recommended that the Transducer be secured by
means other than relying on the plumbing. Two 1/4"
−20 holes are provided on
two faces of the Transducer for this purpose. Any one of the four threaded holes
will provide a ground connection.
CAUTION
Perform a thorough leak check prior to connecting the
Transducer to any process gas. Many of the gasses
used for film growth are toxic at very low exposure
levels. The use of a highly sensitive helium mass
spectrometer type leak detector is mandatory for
safety. See
for the
recommended procedure.
The Transducer’s gas flow is restricted by the inlet and outlet tubing’s 0.058"
inside diameter. This restriction arises from acoustic energy conservation
considerations. The penetration of the inlet and outlet at the extremes of the
Resonant Chamber was chosen so the gas flow within the Resonant Chamber
generally sweeps the entire volume, thereby avoiding the creation of large
stagnant zones and thereby extending response times.
NOTE: Cajon
TM
recommends that VCR type fittings be tightened 1/8 turn past
finger tight for Nickel and stainless steel gaskets. Gaskets should not
be reused.
CAUTION
Do not allow Composer’s transducer to be attached to
gas tubes that can exceed 6200 Torr (1665 kPa) [8.2
atmospheres gauge]. Exposure to excess pressures
can stretch the diaphragms and require on site
rezeroing. See
Applications of pressures in excess of 8.2
atmospheres gauge may cause catastrophic
diaphragm failure. It is recommended that a certified
rupture disk be installed upstream of the transducer to
limit any possible over pressure to less than 8
atmospheres.