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3 electronics, 5 trace oxygen analyzer operational theory 2 – Teledyne 3300TB - Low cost trace oxygen analyzer User Manual

Page 15

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2-5

Trace Oxygen Analyzer

Operational Theory 2

Teledyne Analytical Instruments

2.3

Electronics

2.3.1 General

The signal processing uses an Intel

microcontroller with on-board RAM

and ROM to control all signal processing, input/output, and display functions for
the analyzer. System power is supplied from a universal power supply module
designed to be compatible with most international power sources.

The power supply circuitry is on the Power Supply PCB, which is mounted

vertically, just behind the rear panel of the Control Unit.

The signal processing electronics including the sensor amplifier,

microcontroller, analog to digital, and digital to analog converters are located on
the Main PCB, which is mounted vertically, just behind the front panel of the
Control Unit.

2.3.2 Signal Processing

Figure 2-3 is a block diagram of the signal processing electronics described

below.

Figure 2-3: Block Diagram of the Signal Processing Electronics

ALARMS

ALARMS

DISPLAY

D A C

A D C

KEYBOARD

E–I CONV

SENSOR

AMPLIFIER

TEMPERATURE
COMPENSATION
NETWORK ON
SENSOR PCB

MICRO-
CONTROL-
LER

RELAYS

RELAYS

MFC

4–20 mA dc

0–10 V dc

RANGE ID

Concentration

Millivolt

Potput

Microamp

Output

B-2C Sensor