Teledyne GFC-7000E - Trace CO2 Analyzer - Manual (Page 49)

Model GFC7000E Instruction Manual Optional Hardware and Software
04584 Rev A1 38
5.3. Expendable Kits (Options 42C, 42D and 43)
OPTION NUMBER DESCRIPTION
OPT 42C 1 year’s supply of replacement of 47mm dia. particulate filters
OPT 42D 1 full replacement’s volume of indicating soda-lime for the external CO
2
scrubber included with options 51 & 53 ( approximate active lifetime: 1
year)
OPT 43 Options 42 C & 42D
5.4. Calibration Valves Options
There are four available options involving Zero/Span/Shutoff valves. From an operational and
software standpoint, all of the options are the same, only the source of the span and zero gases
are different.
5.4.1. Zero/Span/Shutoff Valve (Option 50)
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 module 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.
The following table describes the state of each valve during the analyzer’s various operational
modes.
Table 5-1: Zero/Span Valve Operating States for Options 50 & 51
MODE VALVE CONDITION VALVE PORT CONNECTION
(Fig. 5-2)
Sample/Cal Open to SAMPLE inlet 3 Æ 2
Zero/Span Open to ZERO AIR inlet 3 Æ 2
SAMPLE
(Normal State)
Shutoff Valve Closed N/A
Sample/Cal Open to zero/span inlet 1 Æ 2
Zero/Span Open to ZERO AIR inlet 3 Æ 2 ZERO CAL
Shutoff Valve Closed N/A
Sample/Cal Open to ZERO/SPAN inlet 1 Æ 2
Zero/Span Open to SPAN GAS inlet 1 Æ 2
SPAN CAL
Shutoff Valve Open to PRESSURE SPAN
Inlet
1 Æ 2
The minimum span gas flow rate required for this option is 800 cm 3 /min.