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

Trace Oxygen Analyzer Model 31 1TC

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.

Teledyne Analytical Instruments

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)

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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