Teledyne T360, Operation Manual, Page: 53 / 358

Teledyne API Model T360/T360M Operation Manual Getting Started
51
Source of
SAMPLE GAS
Removed during
calibration
VENT
Calibrated
CO
2
Gas
at span gas
concentration
VENT
here if input
is pressurized
Chassis
PRESSURE SPAN
IZS
PURGE LINE
SAMPLE
EXHAUST
VENT SPAN
External
Zero Air
Scrubber
N
2
Figure 3-18: Pneumatic Connections with Ambient Zero/Pressurized Span Valves (Opt 50B) and
External Zero Air Scrubber
This option requires that both zero air and span gas be supplied from external
sources. It is specifically designed for applications where span gas will be
supplied from a pressurized bottle of calibrated CO
2
gas. A critical flow control
orifice, internal to the instrument ensures that the proper flow rate is maintained.
An internal vent line, isolated by a shutoff valve ensures that the gas pressure of
the span gas is reduced to ambient atmospheric pressure. Normally zero air
would be supplied from zero air modules such as a Teledyne Instruments Model
701.
In order to ensure that span gas does not migrate backwards through the vent line
and alter the concentration of the span gas, a gas line not less than 2 meters in
length should be attached to the vent span outlet on the rear panel of the analyzer.
To prevent the buildup of back pressure, this vent line should not be greater than
10 meters in length.
07272B DCN6552