Teledyne 3190Z - Zirconium oxide trace oxygen analyzer - Manual (Page 16)

Operational Theory Model 3190Z
Teledyne Analytical Instruments 8
The sensor is designed for long term stability with an operating
life of 5 years.
This unit features one or two sensors, and can be custom-designed
for a specific range of oxygen analysis.
2.2.2 The Effect of Pressure
In order to state the amount of oxygen present in the sample as a
specific portion of the gas mixture, it is necessary that the sample diffuse
into the sensors under constant pressure.
If the total pressure increases, the rate that oxygen reaches the
sensors will also increase. The electron transfer, and therefore the
external current, will increase, even though the proportion of oxygen has
not changed. It is therefore important that the sample pressure at the
sensors, (usually vent pressure) remain relatively constant between
calibrations.
2.3 Electronics
2.3.1 General
The signal processing uses a 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, which includes the signal
amplifiers, microcontroller, analog to digital converter, and digital to
analog converter, are located on the Main PCB. It is mounted vertically
just behind the front panel of the control Unit.