2-5
Percent 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
A LAR M S
A LAR M S
D IS P LAY
D A C
A D C
K EY BO AR D
E –I C ON V
S EN SO R
A M PLIFIE R
TE M PE RATU RE
C O M PE NS AT ION
N ET W OR K ON
S EN SO R P C B
M IC R O -
C O NT RO L-
LER
R ELAYS
R ELAYS
M FC
4–20 m A dc
0–10 V dc
R AN GE ID
C oncentration
Millivolt
Potput
Microamp
Output
I-22 Sensor