Part I: 2-1
Percent Paramagnetic Oxygen Analyzer Part I: Control Unit
Teledyne Analytical Instruments
Operational Theory2.1 Introduction
The Model 3010MB Oxygen Analyzer Control Unit uses an 80C31
microcontroller with 32 kB of RAM and 128 kB of ROM to control all
signal processing, input/output, and display functions for the Model 3010MB
analyzer. (The sample system and Paramagnetic sensor are covered in Part
II, Analysis Unit, in this manual.) System power is supplied from a universal
power supply module designed to be compatible with any international
power source.
2.2 Electronics and Signal Processing
All of the Analyzer electronics are located on Printed Circuit Board
(PCB) assemblies inside the Control Unit chassis. The PCB locations are
illustrated in section 5, Maintenance.
Refer to Figure 2-1, Block Diagram of the 3010MB CU Electronics:
In the presence of oxygen, the sensor (in the Analysis Unit) generates a
current. A current to voltage amplifier (in the Control Unit) converts this
current to a voltage.
The second stage amplifier amplifies the voltage. The output from the
second stage amplifier is sent to an 18-bit analog to digital converter con-
trolled by the microprocessor.
The digital concentration signal—along with input from the control
panel—is processed by the microprocessor, and appropriate control signals
are directed to the display, alarms and communications port as well as to the
gas control valves in the Analysis Unit.
The same digital information is also sent to a 12 bit digital to analog
converter that produces the 4-20 mA dc and the 0-1 V dc analog concentra-
tion signal outputs, and the analog range ID outputs.
The microprocessor monitors the power supply, and activates the
system failure alarm if a malfunction is detected.