Teledyne 3020T - Manual (Page 20)

2-6
2 Operational Theory Model 3020T
Teledyne Analytical Instruments
Figure 2-4 is the flow diagram for the sampling system. In the standard
instrument, calibration gases (zero and span) can be connected directly to the
Sample In port by teeing to the port with appropriate valves. The shaded
portion of the diagram shows the components added when the –C and/or F
options are ordered. The valves, when supplied, are installed inside the
3020T enclosure and are regulated by the instruments internal electronics.
The flame arrestors, when supplied, are installed in the Gas Connector Panel.
Figure 2-4: Flow Diagram
2.4 Electronics and Signal Processing
The Model 3020T Trace Oxygen Analyzer uses an 8031 microcontrol-
ler with 32 kB of RAM and 128 kB of ROM to control all signal processing,
input/output, and display functions for the analyzer. System power is sup-
plied from a universal power supply module designed to be compatible with
most international power sources. See chapter 5 Maintenance for the location
of the power supply and the main electronic PC boards.
The signal processing electronics including the microprocessor, analog
to digital, and digital to analog converters are located on the motherboard at
the bottom of the case. The preamplifier board is mounted on top of the
motherboard as shown in the figure. These boards are accessible after re-
moving the access panel. Figure 2-5 is a block diagram of the Analyzer
electronics.
In vacuum service the
restrictor should b
placed here.
Sample In
Span In
Zero In
Exhaust O u
Solenoid
Valves
Restrictor
Cell
In normal service the
restrictor should b
placed here.
Components in the s
the -C option (interna
only and are not sho
diagram abov e