Applications Not At Atmospheric Pressure; Sensor Impedance; Electronics; General - Teledyne 9060L Operating Instructions Manual

Operational Theory
THE PROBE/SENSOR MUST ALWAYS BE
CONNECTED TO EARTH.
Power to the heater is supplied directly from the main power
source, and the temperature is initially controlled above 700°C (1300°F)
after power up.

2.3 Applications Not at Atmospheric Pressure

For high and low pressure applications where the pressure at the
point of measurement is significantly above or below atmospheric
pressure, compensation must be applied. The Model 9060L does not
incorporate a pressure sensor thus no compensation is performed. This
factor must be considered when reading concentration from the display
under high or low pressure monitoring conditions.

2.4 Sensor Impedance

The zirconia sensor impedance is a basic measurement of the
reliability of the oxygen reading. A probe or sensor with a high
impedance reading will eventually produce erroneous signals. The
analyzer checks the zirconia sensor impedance every 5 minutes and if
the impedance is above the maximum level for a specific temperature
then the impedance alarm will be activated. Typical sensor impedance
is 1 KΩ to 8 KΩ at 720°C (1320°F).

2.5 Electronics

2.5.1 General

The signal processing uses an Intel
RAM and ROM to control all signal processing, input/output, and
display functions for the analyzer. System power can be either 120 or
220 VAC depending on the position of an internal switch.
The power supply circuitry and temperature controller circuitry are
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,
micro-controller, analog to digital, and digital to analog converters are
Teledyne Analytical Instruments
Model 9060L
®
micro-controller with on-board
20