Teledyne 3350 User Manual
OPERATING INSTRUCTIONS FOR
Model 3350
Oxygen Alarm Monitor
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 M70682
4/11/2014
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Copyright © 2000Teledyne 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 9174
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
acknowledgements 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.
8.
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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Teledyne Analytical Instruments
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Model 3350 complies with all of the requirements of the Commonwealth of Europe (CE) for Radio Frequency Interference, Electromagnetic Interference (RFI/EMI), and Low Voltage Directive
(LVD).
The following International Symbols are used throughout the Instruction Manual for your visual and immediate warnings and when you
have to attend CAUTION while operating the instrument:
GROUND
Protective Earth
CAUTION, The operator needs to refer to the manual
for further information. Failure to do so may
compromise the safe operation of the equipment.
CAUTION, Risk of Electric Shock
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Contents
Introduction
1.1 Overview........................................................................ 1-1
1.2 Main Features of the Analyzer ....................................... 1-1
1.3 Front Panel Description.................................................. 1-2
1.4 Rear Panel Description.................................................. 1-3
Operational Theory
2.1 Introduction .................................................................... 2-1
2.2 Micro-Fuel Cell Sensor .................................................. 2-1
2.2.1 Principles of Operation .......................................... 2-1
2.2.2 Anatomy of a Micro-Fuel Cell................................. 2-2
2.2.3 Electrochemical Reactions .................................... 2-3
2.2.4 The Effect of Pressure............................................ 2-3
2.2.5 Calibration Characteristics ...................................... 2-4
2.3 Electronics ..................................................................... 2-5
2.3.1 General.................................................................. 2-5
2.3.2 Signal Processing .................................................. 2-5
2.4 Alarms............................................................................ 2-6
Installation
3.1 Unpacking the Analyzer................................................. 3-1
3.2 Installation...................................................................... 3-2
3.3 Installing the Micro-Fuel Cell ......................................... 3-2
3.4 Electrical Connections ................................................... 3-2
3.5 Power and Signal Connections ...................................... 3-3
3.6 Calibration ..................................................................... 3-8
3.7 Operation ....................................................................... 3-9
3.8 Cell Warranty ................................................................. 3-10
3.9 Safety Checklist ............................................................. 3-10
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3.5.1 AC and Battery Backed Standby Power ................ 3-3
3.5.2 Battery Backed Standby Power ............................. 3-4
3.5.2.1 Connecting the Rechargeable Battery ..... 3-5
3.5.3 Analog Outputs ...................................................... 3-6
3.5.4 RS-232 Port (optional) ........................................... 3-6
3.5.5 Alarm Relays ......................................................... 3-7
Teledyne Analytical Instruments
3.10 Accessory Flow-Through Adapter ................................. 3-11
Operation
4.1 Using the Function and Data Entry Buttons ................... 4-1
4.2 Alarm Conditions ........................................................... 4-2
4.3 Calibration ..................................................................... 4-2
Maintenance
5.1 Replacing the Fuse........................................................ 5-1
5.1.1 Standard AC Version ............................................. 5-1
5.1.2 AC with Battery Backup Version ............................ 5-2
5.2 Sensor Installation or Replacement ............................... 5-2
5.2.1 When to Replace a Sensor.................................... 5-2
5.2.2 Ordering and Handling of Spare Sensors .............. 5-3
5.2.3 Removing the Micro-Fuel Cell ............................... 5-3
5.2.4 Installing a Micro-Fuel Cell .................................... 5-4
5.2.5 Cell Warranty Conditions ....................................... 5-4
Appendix
A.1 Specifications ................................................................ A-1
A.2 Spare Parts List ............................................................. A-2
A.3 Reference Drawing........................................................ A-3
A.4 Miscellaneous................................................................ A-3
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D ANGER
COMBUSTIBLE GAS USAGE WARNING
This is a general purpose instrument designed for usage in a
nonhazardous area. It is the customer's responsibility to ensure
safety especially when combustible gases are being analyzed
since the potential of gas leaks always exist.
The customer should ensure that the principles of operating of
this equipment is well understood by the user. Misuse of this
product in any manner, tampering with its components, or unauthorized substitution of any component may adversely affect
the safety of this instrument.
Since the use of this instrument is beyond the control of
T eledyne, no responsibility by T eledyne, its affiliates, and a gents
for damage or injury from misuse or neglect of this equipment is
implied or assumed.
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Teledyne Analytical Instruments
Alarm Oxygen Monitor Introduction 1
Introduction
1.1 Overview
The Teledyne Electronic Technologies Analytical Instruments (TET/AI)
Model 3350 is a microprocessor-based Oxygen Alarm Monitor for real-time
measurement of the oxygen content of the atmosphere surrounding its sensor.
The Model 3350 standard instrument is configured to run from an AC
power source and is also available with continuous charging, DC battery backup
option. The rated battery life is approximately 17 hours configured in failsafe
mode and 48 hours in non-failsafe mode.
The instrument is designed as a safety monitor. However, it is the responsibility of the user to establish whether or not the total system or instrument,
environment, alarm components and any other relevant devices will actually
assure safety in his/her particular circumstances.
1.2 Main Features of the Analyzer
• Accurate readings of oxygen content at the standard 0-25% range.
(Consult factory for other ranges)
• Large, bright, light emitting diode meter readout.
• Nylon cell holder.
• Simple pushbutton span controls.
• Advanced Micro-fuel Cell, for percent analysis, has a 12 month
warranty.
• Unaffected by oxidizing gasses.
• Fast response and recovery time.
• Microprocessor based electronics: 8bit CMOS microprocessor with
on-board RAM and 16KB ROM.
• Air calibration range for convenient spanning at 20.9% oxygen.
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1-1
1 Introduction Model 3350
• Two factory preset alarms, form C relay contacts, configured as Failsafe
or Non-Failsafe.
• Sensor failure alarm, form C relay contact, configured as Failsafe or
Non-Failsafe.
• Three analog outputs: two for measurement (0–10 VDC, and
negative ground 4–20 mADC) and one for range identification
(0-10 VDC).
• Optional RS232
• Compact and rugged, wall mounted NEMA-4 rated enclosure.
• CE Approval
1.3 Front Panel Description
All controls and displays except the power switch are accessible from the
front panel. See Figure 1-1. The front panel has three pushbutton membrane
switches, a digital meter, and an alarm indicator LED for operating the monitor.
These features are described briefly here and in greater detail in Chapter 4,
Operation.
1-2
Figure 1-1: Front Panel
Span Key: Pushbutton membrane switch is used to span calibrate the ana-
lyzer:
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Alarm Oxygen Monitor Introduction 1
Data Entry Keys: Two pushbutton membrane switches are used to
manually change the span measurement parameters of the instrument as they are
displayed on the LED meter readout:
• Up Arrow Increment values of parameters upwards as they
are displayed on the LED readout.
• Down Arrow Increment values of parameters downwards as
they are displayed on the LED readout.
Digital LED Readout: The digital display is a LED device that
produces large, bright, 7-segment numbers that are legible in any lighting
environment. It has three functions:
• Meter Readout: As the meter readout, it displays the oxygen
concentration currently being measured.
• Measurement Parameters Readout: It displays the span
calibration point when it is being checked or changed.
• Alarm Condition: It displays intermittently, “CAUt” and the gas
readings when a CAUTION Alarm has been initiated and “dAng”
for DANGER Alarm.
1.4 Rear Panel Description
The rear panel contains the electrical input and output connectors. Separate rear panel illustrations are shown in figure 1-2 for the AC and DC battery
backup versions of the instrument. The connectors are described briefly here
and in detail in the Installation chapter of this manual.
Figure 1-2 Rear Panel, Control Unit - AC
(viewed from inside front door)
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1 Introduction Model 3350
Figure 1-2 Rear Panel, Control Unit - DC
(viewed from inside front door)
• Power Connection AC version: Universal 100–240 VAC, at
50/60Hz. The connector housing includes
the fuse holder and the power switch.
DC Battery Backup Version: , 10 to 36
VDC. Supplied by universal 100-240VAC.
Fuse Holder: Replacing the fuses is
described in Chapter 5, Maintenance.
I/O Power Switch: Turns the instrument
power ON (1) or OFF (0).
• Analog Outputs 0–10 VDC concentration output.
0–10 VDC range ID (or optional
overrange) output.
4–20 mA DC concentration output,
negative ground.
• Digital Output RS232 (optional).
• Audible Alarm Output for standard internal or customer
supplied external audible alarm
(12VDC@5mA).
• Alarm Connections Alarm 1 (CAUTION), Alarm 2
(DANGER), and Sensor Failure Alarm
connections.
1-4
• Sensor Connector Sensor Connector.
Teledyne Analytical Instruments
Alarm Oxygen Monitor Operational Theory 2
Operational Theory
2.1 Introduction
The analysis is specific for oxygen, i.e., the measuring cell will not generate
an output current unless oxygen is present in the sample gas. Thus, the instrument
has an absolute zero and no zero gas is required to operate the analyzer.
The measuring cell has the ability to respond accurately to the presence of
oxygen irrespective of flowrate. TAI recommends using ambient air as a span
gas or, if that is not possible, using a known calibration gas of about 80% of the
range of interest value.
The measuring cell (U.S. Patent #3,429,796) is a solid-state maintenancefree structure that carries a TAI guarantee for performance and usable life. The
cell consumes oxygen from the gas surrounding it and generates a proportional
microampere current. The Control Unit processes the sensor output and translates it into electrical concentration, range, and alarm outputs, and a percent
oxygen meter readout. It contains a microcontroller that manages all signal
processing, input/output, and display functions for the analyzer.
2.2 Micro-Fuel Cell Sensor
2.2.1 Principles of Operation
The oxygen sensor used in the Model 3350 is a Micro-fuel Cell designed
and manufactured by TAI. It is a sealed, disposable electrochemical transducer.
The active components of the Micro-Fuel Cell are a cathode, an anode,
and the aqueous KOH electrolyte in which they are immersed. The cell converts
the energy from a chemical reaction into an electrical potential that can produce a
current in an external electrical circuit. Its action is similar to that of a battery.
There is, however, an important difference in the operation of a battery as
compared to the Micro-Fuel Cell: In the battery, all reactants are stored within
the cell, whereas in the Micro-Fuel Cell, one of the reactants (oxygen) comes
from outside the device as a constituent of the sample gas being analyzed. The
Micro-Fuel Cell is therefore a hybrid between a battery and a true fuel cell. (All
of the reactants are stored externally in a true fuel cell.)
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2 Operational Theory Model 3350
2.2.2 Anatomy of a Micro-Fuel Cell
The Micro-Fuel Cell is made of extremely inert plastic (which can be
placed confidently in practically any environment or sample stream). It is effectively sealed, though one end is permeable to oxygen in the sample gas. At the
permeable end a screen retains a diffusion membrane through which the oxygen
passes into the cell. At the other end of the cell is a connector and temperature
compensation network (restrictors and thermistor) on a printed circuit board.
Refer to Figure 2-1, Basic Elements of a Micro-Fuel Cell, which illustrates the following internal description.
Electrical Connector
Circuit Board
with temperature compensation network.
Anode
Cathode
Teflon Membran e
Screen
Clamp
Figure 2-1. Basic Elements of a Micro-Fuel Cell (not to scale)
At the sensing end of the cell is a diffusion membrane, whose thickness is
very accurately controlled. Near the diffusion membrane lies the oxygen sensing
element—the cathode.
The anode structure is larger than the cathode. It is made of lead and is
designed to maximize the amount of metal available for chemical reaction.
The space between the active elements is filled by a structure saturated with
electrolyte. Cathode and anode are wet by this common pool. They each have a
conductor connecting them, through some electrical circuitry, to one of the
external contacts in the connector receptacle, which is on the top of the cell.
2-2
Teledyne Analytical Instruments
Alarm Oxygen Monitor Operational Theory 2
2.2.3 Electrochemical Reactions
The sample gas diffuses through the Teflon membrane. Any oxygen in the
sample gas is reduced on the surface of the cathode by the following HALF
REACTION:
O2 + 2H2O + 4e– → 4OH
–
(cathode)
(Four electrons combine with one oxygen molecule—in the presence of
water from the electrolyte—to produce four hydroxyl ions.)
When the oxygen is reduced at the cathode, lead is simultaneously oxidized
at the anode by the following HALF REACTION:
2(Pb + 2OH–) → 2(Pb+2 + H2O) + 4e
–
(anode)
(Two electrons are transferred for each atom of lead that is oxidized. TWO
ANODE REACTIONS balance one cathode reaction to transfer four electrons.)
The electrons released at the surface of the anode flow to the cathode
surface when an external electrical path is provided. The current is proportional
to the amount of oxygen reaching the cathode. It is measured and used to
determine the oxygen concentration in the gas mixture.
The overall reaction for the fuel cell is the SUM of the half reactions above,
or:
2Pb + O2 → 2PbO
(These reactions will hold as long as no gaseous components capable of
oxidizing lead are present in the sample. The only likely components are the
halogens—iodine, bromine, chlorine and fluorine.)
The output of the fuel cell is limited by (1) the amount of oxygen in the cell
at the time and (2) the amount of stored anode material.
In the absence of oxygen, no current is generated.
2.2.4 The Effect of Pressure
In order to state the amount of oxygen present in the sample as a percentage of the gas mixture, it is necessary that the sample diffuse into the cell under
constant pressure.
If the pressure changes, the rate that oxygen reaches the cathode through
the diffusing membrane will also increase. The electron transfer, and therefore the
external current, will increase, even though the proportion of oxygen has not
changed.
Fortunately, Dalton's Law confirms that every gas in a mixture contributes
the same pressure to the mixture that it would exert if it were alone in the same
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