Teledyne 3060e - Ultra Trace oxygen analyzer - Manual (Page 20)

2-10
Model 3060E Model 3060E Model 3060E Model 3060E Model 3060E Chapter 2 Chapter 2 Chapter 2 Chapter 2 Chapter 2
Teledyne Electronic Technologies
Analytical Instruments
• Oxygen Scrubber
The O
2
scrubber is used to remove O
2
(down to less than 1 PPB,
typically 0.5 PPB) from the sample gas. The scrubbed gas is used
for:
Sparging
Electrolyte in the Ultra Trace oxygen sensor is sparged with
oxygen-free gas to reduce dissolved oxygen from the electrolyte.
Zero Calibration
The oxygen-free gas is used to electronically offset the back-
ground signal of the Ultra Trace sensor. This provides a zero
point for the system to measure the oxygen content of the
sample gas during analysis.
Span Calibration Using Internal Calibrator
The oxygen-free gas is mixed with oxygen generated in the
electrochemical calibrator to produce a span gas with a known
oxygen concentration. This provides a span point for the system
to measure the oxygen content of the sample during analysis.
NOTE: The standard O
2
scrubber has a capacity of 80 cc of pure O
2
.
Under normal operating conditions, the scrubber is expected to
last several years. The scrubber is installed in the system using
metal gasket and VCR type fittings.
The life of the scrubber is approximately 10 years when subjected
to an O
2
concentration of 10 PPM at a flow rate of 150 cc/min.
• Mass Flow Controller
A mass flow controller is used to control the rate of gas flowing by
the sensing electrode of the sensor. The flow controller is located
upstream of the sensor. It provides signal input to the electronics in
the control module. The flow rate is displayed on the LCD screen
and is typically set at 150 cc/min.
• Fittings
The electropolished 316L stainless steel tees, elbows and crosses
used in the sampling system are orbitally welded for system integrity.
Small size fittings are used to make the sample system compact and
to minimize total system internal volume.