Teledyne IR-7000 - Non-dispersive infrared series - Manual (Page 33)

NDIR Gas Analyzer Installation 3
Teledyne Analytical Instruments., - Rev. 3 25
3.6.2 Analog Output Connections
Output signals from the IR section of the analyzer are available from
the 2 leftmost terminals on the long connector labeled INFRARED
CHANNEL 1. Attach the wires from the output device to the connector at
the terminals labeled VOLT OUT/IR. Make sure the proper polarity is
observed.
If an O
2
channel is installed, connect the 2 wires from the device used
to monitor the O
2
concentration to the terminals labeled VOLT OUT/O2.
Again, observe proper polarity.
If the current output option is installed, connect the 2 wires from the
current driven output device to the terminals labeled mA OUT/IR using
the indicated polarity. Repeat for the O
2
channel at the terminals labeled
mA OUT/O2.
3.6.3 Solenoid Valve Connections
To use the automatic calibration feature of this instrument a pair of
AC solenoid valves must be installed on the sample system. If not
installed by the factory, the customer is responsible for obtaining and
installing the valves into the sample system. Refer to Figures 3-1 and 3-2
for suggested placement. The solenoid valves are driven by isolated triacs.
The triacs can handle a maximum rated load of 0.6 A at instrument
voltage.
The factory recommends using 2 3-way valves to control the sample
and calibration gas flow through the analyzer. See Figure 3-1 and 3-2 for
suggested sample system valve layouts.
To install the electrical connections of the solenoid valves, refer to
Addendum “B” at the back of this manual.
The sense of the valve — flow when energized or flow when de-
energized — depends of the disposition of the 3-way valve in the sample
system. The sense must be correct for your application. When the
autocalibration feature is called by the microprocessor to begin a ZERO
calibration, the solenoid connected to the terminal labeled ZERO will be
energized. The solenoid connected to the SPAN terminal will be de-
energized. See Table 3-1 for the solenoid valve status during
autocalibration for the suggested sample systems given in Figures 3-1 and
3-2.