Valve Control; Figure 6-11: Heater Control Loop Block Diagram - Teledyne T400 User Manual

On instruments with Zero/Span valve option (OPT-50A) the metal wool scrubber option
•
(OPT- 68) there is a DC heater embedded in the scrubber, which maintains it at a
constant 110ºC.
On instruments with the IZS valve option (OPT- 50G) there is a DC heater attached to the
•
IZS O
Thermistor(s) –
Themocouple(s)
(used on Optional Metal
Wool Scrubber)
6.3.3.4

VALVE CONTROL

The valve that switches the gas stream to and from the analyzer's O
measure/reference cycle is operated by an electronic switch located on the relay PCA.
This switch, under CPU control, supplies the +12VDC needed to activate each valve's
solenoid.
Similar valves also controlled by the relay PCA are included in the following optional
components:
On instruments with the ZERO/SPAN valve option (OPT- 50A) there are two additional
•
valves:
• The ZERO/SPAN valve selects which calibration gas inlet (the ZERO gas inlet or the
• The SAMPLE/CAL valve selects either the sample inlet when the analyzer is in
• On instruments with the IZS valve option (OPT- 50G) one additional valve (the
SAMPLE/CAL valve) selects either the sample inlet when the analyzer is in SAMPLE
mode or the dry air inlet when the analyzer is in one of its calibration modes.
154
generator UV Lamp, which maintains it at a constant 48ºC.
3
Photometer Lamp
Temperature and Optional IZS O
3
Generator Lamp Temperature)
RELAY PCA
THERMOCOUPLE
CONFIGURATION
JUMPER
(JP5)
DC
Control
Logic
DC HEATERS
(UV LAMP Heaters)
Metal Wool Scrubber)

Figure 6-11: Heater Control Loop Block Diagram

SPAN Gas inlet) is the source of gas when the analyzer is in one of its calibration
modes.
SAMPLE mode or the calibration gas stream when the analyzer is in one of its
calibration modes.
Teledyne API – Model T400 O
MOTHERBOARD
Preamplifiers
and Signal
Conditioning
Cold Junction
Compensation
Solid State
AC Relays
AC HEATER
(optional
Analyzer
3
A/D
Converter
(V/F)
CPU
scrubber during the
3
083730400A DCN8130