Model 311; Introduction; Description; Method Of Analysis - Teledyne 311 Instruction Manual

1.

INTRODUCTION

1.1 Description: The Teledyne Analytical Instruments (TAI) Model 311 is a
portable, intrinsically safe trace oxygen analyzer which can be operated without an external
power source and reliably calibrated without the use of cumbersome, questionable, so-called
"certified" calibration gases.
The instrument provides for trace oxygen analysis in decade steps ranging from 0-10 to 0-10,000
ppm (full scale) plus a special calibration range that encompasses the known oxygen
concentration of atmospheric air (209,000 ppm).
Sample oxygen is read from an extremely accurate integral meter (0.5% linearity) whose range of
measurement is determined by the position of the range selector switch. The 100 division meter
scale and the multiplying factor indicated by the position of the range switch determine the full
scale oxygen sensitivity of the instrument. The linear 5 inch scale (mirror equipped to eliminate
parallax) provides excellent resolution and accuracy.
Sample gas is introduced and vented via a pair of quick disconnect fittings that feature integral
shutoff valves which automatically close when the mating male fitting is withdrawn. The fittings
are an integral part of the measuring cell manifold so that internal sample passage volume is at an
absolute minimum. Sample flow control, although not critical (0.1 to 10 liters/min.) must be
accomplished with accessory equipment.
1.2

Method of Analysis.

electrochemical transducer which functions as a fuel cell; in this instance, the fuel is oxygen.
Oxygen diffusing into the cell reacts chemically to produce an electrical current that is
proportional to the oxygen concentration in the gas phase immediately adjacent to the
transducer's sensing surface. The linear, but minute, signal produced by the transducer from
trace oxygen is amplified by a two stage amplifier. The dual stages of amplification provide
enough gain to drive the 0-100 microampere meter and thermistor controlled network utilized to
compensate for the positive temperature co-efficient of the transducer.
1.3

Outstanding Features.

the Model 311:
1.3.1 Micro-Fuel Cell: The Micro-Fuel Cell* is a sealed electrochemical trans-
ducer with no electrolyte to change or electrodes to clean. When the cell reaches the end of its
useful life, it is merely thrown away and replaced, as one would replace a worn out battery in a

MODEL 311

TRACE OXYGEN ANALYZER
The sample oxygen is measured by a unique
The following unique features are incorporated into
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