Teledyne 311TC Instruction Manual

Trace Oxygen Analyzer Model 31 1TC

INSTRUCTION MANUAL

MODEL 311TC

TRACE OXYGEN ANALYZER

DANGER

HIGHLY TOXIC AND OR FLAMMABLE LIQUIDS OR GASES MAY BE PRESENT IN THIS MONITORING
SYSTEM.

PERSONAL PROTECTIVE EQUIPMENT MAY BE REQUIRED WHEN SERVICING THIS SYSTEM.
HAZARDOUS VOLTAGES EXIST ON CERTAIN COMPONENTS INTERNALLY WHICH MAY PERSIST FOR

A TIME EVEN AFTER THE POWER IS TURNED OFF AND DISCONNECTED.
ONLY AUTHORIZED PERSONNEL SHOULD CONDUCT MAINTENANCE AND/OR SERVICING. BEFORE

CONDUCTING ANY MAINTENANCE OR SERVICING CONSULT WITH AUTHORIZED SUPERVISOR/
MANAGER.

Teledyne Analytical Instruments

P/N M37928

03/06/00

ECO # 00-0060

i

Trace Oxygen Analyzer Model 31 1TC

Copyright © 1999 Teledyne Analytical Instruments

All Rights Reserved. No part of this manual may be reproduced, transmitted,
transcribed, stored in a retrieval system, or translated into any other language or com­puter language in whole or in part, in any form or by any means, whether it be elec­tronic, mechanical, magnetic, optical, manual, or otherwise, without the prior written
consent of Teledyne Analytical Instruments, 16830 Chestnut Street, City of Industry,
CA 91749-1580.

Warranty

This equipment is sold subject to the mutual agreement that it is warranted by us
free from defects of material and of construction, and that our liability shall be limited
to replacing or repairing at our factory (without charge, except for transportation), or at
customer plant at our option, any material or construction in which defects become
apparent within one year from the date of shipment, except in cases where quotations or
acknowledgments provide for a shorter period. Components manufactured by others
bear the warranty of their manufacturer. This warranty does not cover defects caused by
wear, accident, misuse, neglect or repairs other than those performed by Teledyne or an
authorized service center. We assume no liability for direct or indirect damages of any
kind and the purchaser by the acceptance of the equipment will assume all liability for
any damage which may result from its use or misuse.

We reserve the right to employ any suitable material in the manufacture of our
apparatus, and to make any alterations in the dimensions, shape or weight of any parts,
in so far as such alterations do not adversely affect our warranty.

Important Notice

This instrument provides measurement readings to its user, and serves as a tool by
which valuable data can be gathered. The information provided by the instrument may
assist the user in eliminating potential hazards caused by his process; however, it is
essential that all personnel involved in the use of the instrument or its interface, with the
process being measured, be properly trained in the process itself, as well as all instru­mentation related to it.

The safety of personnel is ultimately the responsibility of those who control
process conditions. While this instrument may be able to provide early warning of
imminent danger, it has no control over process conditions, and it can be misused. In
particular, any alarm or control systems installed must be tested and understood, both as
to how they operate and as to how they can be defeated. Any safeguards required such
as locks, labels, or redundancy, must be provided by the user or specifically requested of
Teledyne at the time the order is placed.

Therefore, the purchaser must be aware of the hazardous process conditions.
The purchaser is responsible for the training of personnel, for providing hazard warning
methods and instrumentation per the appropriate standards, and for ensuring that hazard
warning devices and instrumentation are maintained and operated properly.

Teledyne Analytical Instruments (TAI), the manufacturer of this instrument,
cannot accept responsibility for conditions beyond its knowledge and control. No
statement expressed or implied by this document or any information disseminated by the
manufacturer or its agents, is to be construed as a warranty of adequate safety control

under the user’s process conditions.

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Trace Oxygen Analyzer Model 31 1TC

RFI Immunity

The Teledyne Model 311TC has been tested to the standard required by the
European Community for CE marking, EN 60601-1-2.

The sample subjected to testing passed all sections of this testing with the
exception of the following:

From 150KHz to 16MHz no problems were observed. From
16MHz to 80MHz the meter needle deflected to full scale and then
dropped to zero. The equipment under test required a power cycle
to fully reset.

The power cord is used for battery recharging purposes only and
requires a power cycle in normal operation. Therefore, no failure
occurred with respect to EN 50082-2 performance criteria.

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Trace Oxygen Analyzer Model 31 1TC

T able of Contents

1 Introduction

1.1 Description...................................................................1-1

1.2 Method of Analysis ......................................................1-1

1.3 Outstanding Features .................................................. 1-2

2 Installation

2.1 Sampling Equipment....................................................2-1

2.2 Power Service..............................................................2-1

3 Operation

3.1 Introduction..................................................................3-1

3.2 Positive Pressure Sampling.........................................3-2

3.3 Atmospheric Pressure Sampling..................................3-2

3.4 Calibration ...................................................................3-3

3.4.1 Calibration Procedure Using Calibration Gas . .3 - 3

3.4.2 Calibration Procedure Using Air ....................3 -4

4 Maintenance

4.1 Battery Power Supply Service .....................................4-1

4.2 Routine Maintenance...................................................4 -2

4.3 Micro Fuel Cell .............................................................4-2

4.4 Cell Replacement ........................................................ 4-2

4.5 Transduction and Temperature Compensation............4-4

4.6 Leak Testing ................................................................4-4

Procedure 1. .............................................................4-4

Procedure 2. .............................................................4-5

Appendix

Specifications......................................................................A-1

Recommended Spare Parts List for Model 311TC..............A-2

Drawing List ........................................................................A-2

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Introduction

1.1 Description

The Teledyne Analytical Instruments (TAI) Model 311TC 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 1-10,000 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 4.5 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

The sample oxygen is measured by a unique 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 transducers 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

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0-100 microampere meter and thermistor controlled network utilized to
compensate for the positive temperature coefficient of the transducer.

1.3 Outstanding Features

The following unique features are incorporated into the Model

311TC:

• Micro-Fuel Cell

The Micro-fuel Cell (U.S. Pat. Nos. 3,767,552 and 3,668,101) is
a sealed electrochemical transducer 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 flashlight. The life of the cell is
warranted by TAI (see Section 4.4) in a fashion similar to that
employed by the manufacturers of automobile batteries. This
procedure guarantees the customer compensation for failure of a
given cell to perform as specified.

• Reliable Calibration

The unique qualities of the Micro-fuel Cell allows the user to
calibrate the instrument with the most economical, reliable,
abundant, standardization gas there is — atmospheric air.

The special “CAL” range of the instrument features a mark that
coincides with the 209,000 ppm oxygen concentration of air. By
drawing air through the instrument (see the sample calibration
procedure in Section 3.2) reliable calibration can be achieved.

The electronics have been properly zeroed (a onetime factory
operation), so that the instrument does not produce an output
indication in the absence of oxygen. Refer to Section 3.2 if
readjustment is required.

• Integral Power Supply

The differential power requirement (plus and minus 3.6 volts
D.C.) of the instrument amplifier is furnished by two internally
mounted 750 milliampere hour nickel cadmium batteries. Fully
charged, these batteries will provide enough power to operate
the instrument continuously for a period of about thirty-five (35)
days. Furthermore, an overnight charge on a one-month duty

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cycle should keep the original batteries supplied usable for many
years.

An integral charging circuit and a detectable power cord are
provided so that the batteries may be recharged from any 50 or
60 cycle, 220/240V (or with option, 105 to 125V) convenience
outlet.

The instrument is designed to either sample or have its batteries
recharged. Both operations cannot be carried out
simultaneously. TAI has deliberately interlocked the circuitry so
that both operations cannot be carried on at the same time.

Only when the selector switch is placed in the OFF position will
the neon lamp on the back plate of the Model 311TC light up to
indicate power to the battery charging circuit.

A current limiting resistor is potted into the end of each battery.
This assures that under no circumstances can more than 25
milliamperes (100 milliwatts) be switched or drawn from either
battery supply. This means that the Model 311TC may be used
in explosive atmospheres where arcs of 100 milliwatts or less
can be tolerated. The Model 311TC meets CENELEC approval
requirements as intrinsically safe for Group IIC Temperature
Class T4, hazardous locations as approved by BASEEFA
EX86B2228.

CAUTION: This safety feature does not apply when the instrument is being

charged (AC power cord connected and selector switch in the
“OFF” position). The instrument should not be used in explo­sive atmospheres when the batteries are being charged.

To determine the state of the rechargeable batteries, turn the
range selector knob counterclockwise to the battery test position
and hold there. The knob is a spring loaded switch. Observe that
the meter indicator stays within the battery limits. If it does not,
then recharge or replace the batteries. Release the Range
Selector Switch, it will automatically return to the OFF position.

• Accuracy and Response

The Model 311TC provides monitoring accuracies of ±2% of
full scale or ±1 ppm, whichever is greater, at constant
temperature. A ±5% of full scale accuracy is achievable
throughout the operating temperature range of 0 to 50 deg C.

With a sample flowrate of 150 cc/min. 90% response is achieved
in 10 seconds in the X10, X100, X1000, and CAL range switch

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positions. When in the X1 (0-10 ppm) range, 90% response is
realized in 60 seconds.

• Compact Packaging

The instrument is housed in 6-1/8 X 9-1/2 X 5-5/8 in aluminum
case that is equipped with a carrying handle and foot pads.
When in use, the analyzer should be placed in an upright position
on a level surface (off level positioning will detract from meter
accuracy).

Access to the instrument interior is gained by loosening (ccw)

1

the three (3)
the outer case. The case may then be detached from the control
panel assembly. Further disassembly may be accomplished by
removing the back plate assembly from its four (4) mounting
standoffs and laying the two separated assemblies out as
illustrated on the analyzer wiring diagram. The diagram is
included among the drawings at the rear of the manual.

/4 turn screw driver type fasteners on the back of

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Installation

2.1 Sampling Equipment

The customer must provide a means of controlling the pressure and
flowrate of the sample gas. For positive pressure applications, TAI/AI
suggests a simple throttle valve installed in the sample line between the
sample point and the analyzer. The flowrate should be limited to between 0.1

and 10 liters/min.

No te : If a pressure regulator is necessary or desirable, it must have a

metallic diaphragm. Regulators with organic or plastic diaphragms
are permeable to oxygen and, if used in the sampling system, will
lead to high oxygen readings.

For atmospheric pressure sampling, connect a pump and flow control
valve downstream from the analyzer and draw (rather than push) the sample
through the instrument.

TAI/AI supplies three (3) male disconnect fittings with the instrument:
one for installation of the customer’s sample line; one to be used to open the
vent fitting of the instrument; and one (equipped with a plastic tube) for
drawing air through the unit for calibration purposes.

2.2 Power Service

A source of single phase, 105 to 125 volt, 50 or 60 Hz power, capable
of delivering a maximum of ¼ ampere of current will be periodically re­quired to recharge the instrument’s battery power supply. An internationally
approved 3 wire detachable power cord is provided with the instrument and
should be stored in a safe place when not in use.

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Operation

3.1 Introduction

The Model 311TC is supplied completely assembled and ready for
instant use. The Micro-fuel Cell is in place within the manifold, and prior to
shipment the manifold was purged with an inert gas to eliminate all but
traces of oxygen from the internal sampling system. The integral shut-off
valves in the quick disconnect sample fittings, if not disturbed, will maintain
this inert atmosphere within the manifold indefinitely. This can be demon­strated by advancing the range selector switch to the X100 (0-1,000 ppm)
position.

When the range selector is advanced from the “OFF” position, power
to the instruments circuitry is established. The meter will instantly respond
to the residual oxygen within the integral sample passages.

It is impossible to achieve a “perfect” seal of the internal sample
system, and what the meter is indicating is the diffusion — consumption
balance point of the internal sample system and the Micro-fuel cell.

This “balance” point, with a properly calibrated instrument, is always
within the limits of the X100 range. If the reading climbs off the limits of
this scale, a leak in the manifold assembly is indicated.

Note: To extend the cell life and minimize the time required to make the

next analysis, the instrument should always be purged with the
sample or inert gas prior to being taken out of service for standby
or storage.

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3.2 Positive Pressure Sampling

When connecting the instrument to a positive pressure sample source,
always proceed as follows:

1) Before making any connections to the instrument, establish a

flowrate in the sample line of from 0.1–10 liters/min using a
throttle valve between the positive pressure source and the
instrument inlet (1–2 liters/min is suggested). Allow the sample
to vent to atmosphere long enough to purge the line free of air.

2) Install the vent fitting first, and then the sample source fitting.

Be prepared to make the connections in rapid order, so that
atmospheric diffusion time through the vent fitting is held to a
minimum.

When disconnecting the instrument, reverse the procedure: source
fitting first, and then vent fitting.

The objective of the connection — disconnection procedure is to
refrain from pressurizing the manifold.

Note: If a flowing sample was connected to the manifold without the vent

fitting in place, the pressure in the manifold would rise and equili­brate to the sample pressure almost immediately.

In such a situation, depending on the magnitude of the sample pres­sure, leaks in the manifold could result.

3.3 Atmospheric Pressure Sampling

If the sample is at atmospheric pressure (or slightly negative), a
sample pump will be required downstream from the analyzer. The inlet
side of the pump should also be equipped with a throttle valve so that
sample flow can be reduced to between 0.1 and 10 liters/min (1–2 liters/min
is suggested). If pump loading is a consideration, the inlet side of the pump
will have to include a bypass path that is open to the atmosphere through an
additional throttle valve. The sample path and bypass path may then be
balanced by manipulating the two valves, so that sample flow is within the
prescribed limits without loading the pump.

Note: Under no circumstances should there be any restrictions in the line

between the sample point and the analyzer.

If this should occur, a partial vacuum would be drawn on the cell.
Since the cell is a partial pressure sensitive device, any oxygen readings

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taken under these conditions would be erroneous. Pressure less than 0.3
atm. could damage the cell.

3.4 Calibration

The inherently constant output of the cell during its useful life elimi­nates the need for frequent calibration. TAI feels that the interval between
calibrations should be dictated by the customer’s application.

Note: Do not calibrate the instrument unless there is a trace oxygen gas

readily available for purging immediately following the calibration
procedure.

The Model 311TC should be calibrated using a span gas with a known
oxygen concentration. Ambient air (20.9% or 209,000 ppm) may be used
for calibration, but air calibration requires a longer cell stabilization period
before the analyzer can be used for trace analysis. This waiting period can
be minimized by calibrating with a span gas having a low oxygen concentra­tion. Air calibration is not recommended in cases where the analysis will be
performed in ranges of 0-100 ppm or less. This is due to the long stabiliza­tion period required for the instrument to recover from the 209,000 ppm
oxygen in air.

Using a span gas, the analyzer can be calibrated on any range. The
span gas concentration should be within 70% to 90% of full scale of the
range selected.

Note: Using a span gas with a concentration greater than 100% of full

scale will put you in the next range and result in a reduced accu­racy.

Prior to calibration, allow the oxygen reading to come to a reasonably
stable value with zero or sample gas flowing through the analyzer.

3.4.1 Calibration Procedure Using Calibration Gas

It is recommended to calibrate the instrument using a gas source with a
known concentration of oxygen, preferably with a concentration between
70–90% of full scale on the range you are primarily interested in. For
example, if you anticipate your sample gas will contain 0–50 ppm oxygen,
obtain a calibration gas with 70–90 ppm oxygen and calibrate the instrument
on the 0–100 ppm range.

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To calibrate the instrument using a lab analyzed calibration gas use the
following procedure:

1) Stand the instrument upright on a level surface, and with the
range switch in the “OFF” position, check the alignment of the
meter pointer with the zero mark on the scale. Use the mirror to
eliminate parallax, and adjust the screw on the face of the meter,
if necessary, until the pointer and zero mark are in precise
coincidence.

2) Advance the range switch to the range position containing the
concentration of the calibration gas.

3) Connect the calibration gas to either of the instrument's sample
port using a quick disconnect fitting. Use a blank quick
disconnect fitting on the other port to open the seal.

Always connect the vent fitting first followed by the source

fitting.

The analyzer is insensitive to flow rate, however for calibration,
use a flow rate similar to the sample flow you will be using. If
the flow rate will vary or is unknown, use a flowrate between
1–2 liters per minute. Allow sample to flow for several minutes
to flush the sample line. Watch the output of the meter for the
reading to stabilize.

4) Unlock and adjust the span control until the meter pointer is in
coincidence with the concentration of the calibration gas.

Note: Be sure that you relock the control after the adjustment is made.

5) Immediately after step 4 has been accomplished, disconnect the
calibration source gas fitting at the analyzer sample port, and
plug in either the sample or a source of zero gas.

Always disconnect the source fitting first, immediately followed by

the vent fitting.

The benefit of using this procedure is that less time is required to

recover to zero from the calibration source gas.

3.4.2 Calibration Procedure Using Air

To calibrate the instrument with atmospheric air as a standard, use the

following procedure:

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1) Stand the instrument upright on a level surface, and with the
range switch in the “OFF” position, check the alignment of the
meter pointer with the zero mark on the scale. Use the mirror to
eliminate parallax, and adjust the screw on the face of the meter,
if necessary, until the pointer and zero mark are in precise
coincidence.

2) Advance the range switch to the “CAL” position.

3) Install the plastic tube equipped male disconnect fitting in either
of the analyzer’s sample ports, and a blank disconnect fitting in
the other port (direction of sample flow is of no importance). A
pump is recommended on the plastic tube. Pump the tube until
the meter reading is stable.

CAUTION: Do not use your mouth as a siphon. The micro-fuel cell could

leak. This cell contains potassium hydroxide solution (KOH)
which is caustic and extremely hazardous.

4) Unlock and adjust the span control until the meter pointer is in
coincidence with the “CAL” mark on the meter scale.

Note: Be sure that you relock the control after the adjustment is made.

5) Immediately after step 4 has been accomplished, disconnect the
tubing equipped calibration fitting, and plug in either the sample
or a source of zero gas.

If the instrument is to be used for sampling after the calibration proce­dure has been completed, follow the decreasing oxygen reading by position­ing the range switch so that the meter gives the best possible resolution of
the oxygen. Do not attempt to take a reading until the meter indication
stabilizes. If the sample oxygen content lies within the limits of the X1
range (0-10 ppm), an overnight purge is recommended for the instrument to
recover sufficiently from the effects of the 209,000 ppm oxygen concentra­tion of air (over four decades of range differential). Recovery time is
proportionally less in the coarser ranges.

If, on the other hand, the instrument is not to be used immediately after
calibration, and a low ppm oxygen gas is being employed as a purge, allow
the manifold to be purged overnight, and then disconnect both male fittings.

Always disconnect the source fitting first, immediately followed by the
vent fitting.

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Maintenance

4.1 Battery Power Supply Service

The Model 311TC is designed to be intrinsically safe, and therefore is
for use only when it is not connected to the AC power line. TAI suggest
that an overnight recharge be accomplished every four (4) weeks of con­tinuous use. To recharge the batteries, place the range switch in the “OFF”
position and connect the power cord to a convenient outlet.

Note: The amber charge lamp (back of case) will be lit during charging.

The integral charging circuit will automatically energize and regulate
the battery charging current when the switch is in the “OFF” position and
the AC cord is plugged into the power line.

CAUTION: Do not turn the range switch either to "BATT TEST" or to any

other operating position while the unit is connected to a power
line. Doing so may damage the equipment.

When recharging is completed, unplug the unit from the AC outlet.
Turn the range switch to the operating position and then to the “BATT
TEST” position.

Note: The “BATT TEST” position will not give a reliable indication of the

battery charge immediately after a charge cycle. Allow the unit to
run for several minutes before testing the batteries.

In the "BATT TEST" position, the meter should indicate between the
6 and the 8 on the 0-25% scale.

If the instrument is stored with the range switch in the “OFF” position
(charge cord disconnected), the period of time between charge periods is
extended from one month to four months. However, do not leave it longer
than this time period.

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4.2 Routine Maintenance

Beyond adhering to a battery recharge schedule, no routine mainte­nance is required, as there are no moving parts in the instrument other than
the meter movement. The Micro-fuel Cell is a sealed, modular component
that should be replaced only when faulty.

4.3 Micro Fuel Cell

The Class B-2 cell employed in the Model 311TC is warranted for six
(6) months from the date of shipment.

With regard to spare cells, service time starts when the cell is removed
from its shipping package. The customer should stock only one spare cell
per instrument at a time. Do not stockpile spare cells.

The standard Model 311TC is equipped with a Class B-2 Micro-Fuel
cell installed. This particular Micro-Fuel cell is a general purpose sensor for
use in inert gas and hydrocarbon streams and should not be used in applica­tions where CO2 is a major component in the sample. Concentrations of
1,000 ppm or less will not effect the cell performance. Other Micro-Fuel
cells are available for applications with sample gases containing carbon
dioxide.

If a cell was working satisfactorily, but ceases to function before the
warranty period expires, the customer will receive credit toward the pur­chase of a new cell.

If you have a warranty claim, you must return the cell in question to
the factory for evaluation. If it is determined that failure is due to faulty
workmanship or material, the cell will be replaced at no cost to the cus­tomer.

Note: Evidence of damage due to tampering or mishandling will render

the cell warranty null and void.

4.4 Cell Replacement

The characteristics of the Micro-fuel Cell are similar to those of a
mercury battery in that both provide an almost constant output through
their useful life, and then fall off sharply towards zero at the end. If the
sample being analyzed has a low (X1 range) oxygen concentration, cell
failure will probably be indicated by the inability to properly calibrate the
analyzer. The user will find that very little adjustment of the 10-turn span

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potentiometer will be required to keep the analyzer calibrated properly
during the duration of a given cell’s useful life. If large, many turn adjust­ments (cw) are required to calibrate the instrument, or calibration cannot be
achieved within the range of the control, the cell should be immediately
replaced.

To offset the possibility of not having a replacement cell available
when it is needed, TAI/AI recommends that a spare cell be purchased
shortly after the instrument is placed in service, and each time the cell is
replaced thereafter.

The spare cell should be carefully stored in an area that is not subject
to large variations in ambient temperature (75 deg. F nominal), and in such
a way as to eliminate any possibility of incurring damage. Under no cir-

cumstances, disturb the integrity of the cell package until the cell is to
be actually used. If the cell package is punctured and air permitted to

enter, the cell will immediately start to react to the presence of oxygen.

No tools are required to replace the cell in the instrument. Simply
unscrew (ccw) the plug at the bottom of the analyzer and the cell will drop
out of the manifold cavity.

Remove the new cell from its package, and carefully remove the
shorting device.

Note: Do not touch the silver colored sensing surface of the cell. It is

covered with a delicate Teflon membrane that can be ruptured in
handling.

Place the cell on the end of the manifold plug so that the sensing
surface of the cell is in contact with the plug and the electrical contact plate
end of the cell is facing upwards. Insert the cell and plug in the manifold
cavity, and screw the plug back into place. Apply as much pressure as you
can with your fingers, but use no tools.

After the cell has been installed, purge the instrument with an inert gas
(or the sample), and then proceed as directed in Section 3.2.1.

4.5 Transduction and Temperature
Compensation

The Micro-Fuel Cell has an inherent positive temperature coefficient,
the effects of which have been minimized through the implementation of a
calibrated thermistor compensation circuit.

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Internal electronic calibration is accomplished by TAI. However,
should there be any doubt concerning it, the following procedure can be
used to recalibrate. Refer to the schematic.

1. Disconnect cell

2. Move range switch to “cal” position.

3. Adjust R1 (designated as R1 on schematic C37936 and
designated on the A1 PCB module assembly as R28) such that
the output of A1, pin 6, measures between 0 and +0.5 mV,
ideally +0.3 mV.

4. Adjust R2 (designated as R2 on schematic C37936 and
designated on the A3 PCB module assembly as R28) for 0 + 1
mV at output of A2, pin 6.

5. Verify that the offset is the same on all ranges.

6. Reconnect cell.

4.6 Leak Testing

Note: If a leak is suspected in the unit, do not attempt to tighten the

disconnect fittings. The fittings are potted in epoxy and tightening
them will break the seal.

To check for leaks, TAI recommends one of the following procedures:

Procedure 1.

1. Purge the instrument down as low as possible.

2. Place the vent line in water and disconnect the sample.

3. Next, disconnect the vent line and place the range switch on the
X100 range.

4. The unit should stay on the X100 range if there are no leaks.

Procedure 2.

1. Purge the instrument with nitrogen at the sample port.

2. Note the reading once is has stabilized (at least 24 hrs. on the
0–10 ppm range) and increase the flow rate.

3. If the reading goes down, the unit, or the tubing to the unit, has
a leak.

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SENSOR

CLASS

(P/N)

A-2C

(C6689-A 2C)

A-2CI

(C6689-A 2C-

I)

B-2C

(C6689-B 2C)

B2 C6689-

B2

TYPICAL

BA CK G R OU ND APPLIC ATION NOTES WARRANTY

The Clas s A-2C Mi cro-Fuel C ell is id eal for mea suring oxygen fr om

5-100% CO2

1-30% CO2

H2, He, C2H4 The Class B-2C Micro- Fuel Cell is rec ommended for applica tions

N2, Ar,

Hy drocarbon s

low t o 5,0 00 ppm oxygen in ga ses c o nt aining CO 2 . The level of CO 2
may var y over a wide range, and will not affect the sensor
performance. The sensor should not be exposed to air for extended
periods of time as this will shorten its useful life.

The Class A-2CI Micro-Fuel Cell is recommended for applications
where CO2 levels are low (less than 30%). Sensor will take about 1
to 2 days to equilibrat e with the CO2. Can be used in mixtures of H2
and CO2.

involv ing lighte r gas es.

The Class B-2 Micro Fuel Cell is a general purpose trace oxygen
sensor for use in inert and hydrocarbon streams.

6 months

6 months

6 months

6 months

Table 4-1: Micro-Fuel Cell Applications

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T race Oxygen Analyzer Maintenance 4

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T race Oxygen Analyzer Appendix

Appendix

Specifications

TBE/AI Sales Order Number:

Instrument Model Number: 311TC

Instrument Serial Number:

Micro-fuel Cell Class: B-2

Accuracy: ±2% of scale or ±1 PPM (whichever

is greater) at constant temperature;
±5% of full scale or ±1 PPM (which­ever is greater), over the operating
temperature range.

Operating Temperature Range: 30oF to 125oF

Response and Recovery: At the specified flowrate (0.25 scfh)

90% in 10 seconds on the X10, X100,
and X1000 ranges, and 90% in 60
seconds on the X1 range.

Ranges of Analysis: X1 : 0–10 ppm Oxygen

X10 : 0–100 ppm Oxygen
X100 : 0–1,000 ppm Oxygen
X1000 : 0–10,000 ppm Oxygen

Recommended Span Gas: Atmospheric air, or span gas 70–90%

of full scale on range of interest or 1–2
decades higher

Teledyne Analytical Instruments

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T race Oxygen Analyzer Appendix

Recommended Spare Parts List for

Model 311TC

QTY PART NO. DESCRIPTION

1 F1122 IEC Fuse, 1/4 Amp. (for 220V units)
1 F1123 IEC Fuse, 1/2 Amp. (for 110V units)
1 C06689-B2 Micro-fuel Cell, Class B-2
2 B-9905 Battery
1 L79 Lamp

A minimum charge is applicable to spare parts orders.

IMPORTANT: Orders for replacement parts should include the part number

(if available) and the model and serial number of the system
for which the parts are intended.

Send Orders to:

TELEDYNE ANALYTICAL INSTRUMENTS

16830 Chestnut St.
City of Industry, CA 91749-1580

Phone [phone], FAX [phone]
Web: www.teledyne-ai.com

Drawing List
Model 311TC

C-41712 Pictorial Diagram
C-37936 Schematic
C-37938 Wiring Diagram (220V)
C-41661 Wiring Diagram (110V)

Teledyne Analytical Instruments

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