Teledyne 1220 User Manual

Instruction Manual

Model 1220

Multi - Channel

Combustible

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.

P/N M68325

ECO: #00-0203

05/25/2000

Teledyne Analytical Instruments

i

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.

ii

Teledyne Analytical Instruments

Specific Model Information

The instrument for which this manual was supplied may incorporate
one or more options not supplied in the standard instrument. Commonly
available options are listed below, with check boxes. Any that are incorpo­rated in the instrument for which this manual is supplied are indicated by a
check mark in the box.

Instrument Serial Number: _______________________

Options Included in the Instrument with the Above Serial Number:

Dual-Sensor
A second sensor PCB is installed to allow the Channel

Module(s) to monitor two sensors simultaneously.

Teledyne Analytical Instruments

iii

IMPORTANT NOTICE

The 1220 is a safety monitor. However, it is the responsibility of the
user to establish whether or not the total system of instrument, environ­ment, alarm components, and any other relevant devices actually will
assure safety in his particular circumstances.

Location of the equipment and sensors to insure proper operation is
responsibility of the user.

The safety checklist outlined here should be treated only as a guide. It
is up to the user to establish practical safety precautions. It is vital that the

operator understand and test the operation of the total system.

Safety Checklist:

❑ Verify that the instrument is powered correctly.

❑ Verify that the instrument works (all functions).

❑ Verify that alarm indications give the intended results.

❑ Verify that unauthorized personnel cannot tamper with the

instrument or its auxiliary equipment.

iv

❑ Institute routine test/calibration procedures.

❑ Identify and handle any sampling or location problems.

❑ Provide all necessary warning labels and verify that the

labels are on the equipment.

❑ Train all operators to understand all operations and func-

tions of the analyzer and the system.

❑ Identify and handle any environmental or other influences

that could affect the operation of the instrument.

Teledyne Analytical Instruments

Table of Contents

Introduction

1.1 Overview........................................................................... 1-1

1.2 Description........................................................................ 1-1

1.2.1 System Chassis ............................................................ 1-2

1.2.2 Control Unit ................................................................... 1-2

1.2.3 Channel Modules .......................................................... 1-2

1.2.3.1 Main Featuress of the Channel Module............... 1-2

1.2.4 Detector......................................................................... 1-2

1.2.5 Terminal Strip Housing .................................................. 1-2

Operational Theory

2.1 Introduction .................................................................... 2-1

2.2 System Chassis ............................................................. 2-1

2.3 Control Unit .................................................................... 2-1

2.4 Channel Module............................................................. 2-3

2.5 Combustible Sensors..................................................... 2-3

2.5.1 Response of Combustibles to Various Gases .............. 2-7

Installation

3.1 Unpacking the Analyzer ................................................. 3-1

3.2 System Chassis ............................................................. 3-2

3.2.1 Location ................................................................ 3-2

3.2.2 Power .................................................................... 3-2

3.2.3 Electrical Connections .......................................... 3-2

3.3 Control Unit .................................................................... 3-5

3.3.1 ControlUnit Fuses........................................................ 3-5

3.3.2 Control Unit Jumper Settings ...................................... 3-6

3.4 Channel Modules ........................................................... 3-8

3.4.1 Removing the Channel Module Cover......................... 3-8

3.4.2 Changing the Fuse ...................................................... 3-8

3.4.3 Adding or Removing the Second Sensor PCB ............ 3-9

3.4.4 Configuring the Internal Jumper Connections ............. 3-9

3.5 Combustible Sensors................................................... 3-10

Operation

4.1 Introduction .................................................................... 4-1

4.2 Control Unit Operation ................................................... 4-2

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4.2.1 System Power Switch and LED ................................... 4-2

4.2.2 Audible Alarm Switch and Bypass LED....................... 4-2

4.2.3 Fuses .......................................................................... 4-2

4.2.4 RS485 Port.................................................................. 4-2

4.3 Channel Module Front Panel Controls & Indicators ....... 4-4

4.4 Calibration Procedures .................................................. 4-7

4.4.1 Zero Calibrating a Single Sensor Ch. Module ............. 4-7

4.4.2 Span Calibrating a Single Sensor Ch. Module ............ 4-8

4.4.3 Zero Calibrating a Dual Sensor Ch. Module................ 4-9

4.4.4 Span Calibrating a Dual Sensor Ch. Module............... 4-9

4.4.5 Using the "1MAN" Calibration Option. ....................... 4-10

4.4.5.1 Zero & Span Calibrating a Single Sensor Ch. M. ... 4-10

4.4.5.2 Zero & Span Calibrating a Dual Sensor Ch. M....... 4-10

4.5 Alarm Configuration Procedures .................................. 4-11

4.5.1 Defining the Setpoint for the High or Caution Alarm .. 4-11

4.5.2 Configuring Alarm Relay Settings ............................. 4-11

4.5.2.1 Setting the Fail-safe or Non Faile-safe Mode .. 4-11

4.5.2.2 Setting the Latching or Non-Latching Mode ... 4-12

4.6 Setting the ID Code ..................................................... 4-12

4.7 Enabling/Disabling the Pass Code ............................... 4-12

4.8 Setting the Sensitivity Gauge....................................... 4-13

4.9 Routine Operation........................................................ 4-13

4.10 FAIL Alarm Conditions ................................................. 4-14

4.11 Calibration of Combustible Gas Detectors to the LEL of

Gases other than Methane .......................................... 4-14

Failure and Error Codes

5.1 Failure Codes................................................................. 5-1

5.2 Error Codes ................................................................... 5-2

Appendix

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

A-2 Recommended Spare Parts List .................................... A-2

A-3 Drawing List ................................................................... A-3

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Teledyne Analytical Instruments

Multi-Channel Combustible Monitor Introduction 1

Introduction

1.1 Overview

The Teledyne Analytical Instruments (TAI) Model 1220 is a multi­channel system that can be used for determining the concentration of com­bustible gases in an atmosphere at a number of remote locations, and pro­vide alarm information when the combustible gas level exceeds predeter­mined limits at any one or all of the remote locations.

The combustible gas content of the atmosphere is determined by a
number of remotely located detectors that may be strategically placed to
monitor the atmosphere surrounding their location.

The system is designed to provide indications of the state of each
detector and to actuate individual external alarm indicators as well as alarms
common to all channels. The alarms are user-configurable.

Channel Modules

System

Chassis

1.2 Description

The 1220 system is comprised of a System Chassis, Control Unit,
Channel Modules, and Remote Sensors. Each System Chassis contain one
Control Unit and up to eight Channel Modules. Each Channel Module
monitors up to two remote sensors. Since the sensors are designed for
installation in hazardous locations and are suitable for use in NEC Class I,
Division I, Groups B, C and D areas, they are (generally) located in an area
away from the 1220 System.

Control Unit

Model 1220 System

Teledyne Analytical Instruments

1-1

1 Introduction Model 1220

1.2.1 System Chassis (19” Rack)

The System Chassis provides structural support and electrical intercon­nection for the Control Unit and Channel Modules (up to eight Channel
Modules may be installed). These latter plug into the sockets of the system
chassis. Terminal strips at the rear of the System Chassis provide for
external electrical connections.

1.2.2 Control Unit

The Control Unit handles power distribution to the entire system. The
main power is controlled by a switch on the front panel and the system fuses
are accessible from the front. The Control Unit also contains common
alarm relays, which indicate alarm conditions whenever any of the Channel
Modules alarm.

1.2.3 Channel Modules

Each channel module is a complete, self-contained instrument including
integral power supply, and requires only external AC power. A channel is
operational simply when plugged into the System Chassis.

Because a channel module plugs into the control module, channels can
easily be added after installation to monitor additional locations on any
control module originally supplied with less than eight channels. Channel
Modules in the same System Chassis may still be configured independently.

1.2.3.1 Main Features of the Channel Module

The main features of the Channel Module Include:

• High resolution 0-100% LEL LCD display readout

• Drop in replacement for Model 122 instruments

• 1MAN calibration capability

• Membrane switch control

• Rugged sensor design

• 2 sensors per channel option

• Microprocessor based electronics

1-2

• Two concentration alarms with adjustable set-points

• Sensor failure alarm

• User friendly touch key controls

• Passcode protection

Teledyne Analytical Instruments

Multi-Channel Combustible Monitor Introduction 1

Model 1220 Combustible Monitor Front Panel

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1-3

1 Introduction Model 1220

• Failure codes and testpoints

• Two selectable analog outputs (0-10VDC or negative ground
4-20mADC)

• Extensive, automatic self-test diagnostic testing during operation

• Compact and versatile design: Small footprint with accessible

internal PCBs

1.2.4 Detector

The detector is a low temperature, catalytic oxidation, diffusion type
sensor. Each detector contains two beads: a catalytically active bead and a
thermally identical inert bead. Each bead is integrated onto a platinum
heating coil and is mounted on a stainless steel support bar. With this
rugged mounting system the detector is extremely vibration and shock
resistant. The detectors are installed near the potential source of leaks in
the region expected to be first exposed to the gas.

Combustible Gas Detector

1.2.5 Terminal Strip Housing

The terminal strip housing and probe mounts provided for this system
are junction boxes having two hubs with 3/4” pipe treads. The sensor
screws into one hub and the other hub will accommodate standard conduit.

A three-point terminal strip is installed within the housing for connec­tion of the probe.

1-4

Teledyne Analytical Instruments

Multi-Channel Combustible Monitor Operational Theory 2

Operational Theory

2.1 Introduction

The Model 1220 combustible gas analyzer is composed of four com-

ponents:

1. System Chassis

2. Control Unit

3. Channel Modules

4. Combustible Sensors

The System Chassis provides structural support and electrical inter­connection for a Control Unit and up to eight Channel Modules. Each
Channel Module can monitor one or two sensors (dual-sensor option).

2.2 System Chassis

All electrical connections are located on the rear of the system chassis.
The nine terminal strips constitute one each for the Channel Modules and
one for the Control Module.

2.3 Control Unit

The Control Unit provides control of electrical power to the channel
module, audio alarms and external alarms through the common alarm
relays.

Alarm signals from any Channel Module trigger the corresponding
relays in the Control Unit. For example, “high” alarm signals from any
channel trigger the “high” alarm relay in the system control module. There
are three such relays in the Control Unit, one each for high, caution and
failure alarms. The failure alarm relay in the Control Unit is operated
“fail-safe”; however, the gas level alarm relays can be optionally connected

Control Unit - Front Panel

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2-1

2 Operational Theory Model 1220

PRIMARY

POWER

SIGNALS FROM
CHANNEL MODULES

*HIGH

*CAUTION

FAILURE

DRIVERS

POWER
SWITCH

RELAYS

AUDIBLE

ALARM BYPASS

INTERNAL
BUZZER

Control Unit - Block Diagram

for operation in the “non fail-safe” mode by setting the configuration
jumpers as indicated in the installation section 3.3.2. Each of these relays
provides SPDT contacts for operation of external devices.

POWER TO

CHANNEL
MODULES

POWER FOR
EXTERNAL
AUDIBLE
ALARMS

RELAY
CONTACT
ACTUATION

HIGH

CAUTION

FAILURE

An audible alarm is actuated when any alarm state occurs. This
audible alarm may be disconnected by switching the AUDIBLE ALARM
control switch to the BYPASSED position. When this is done, the red
lamp on the system module is illuminated as an indication that the audible
alarm is not functioning.

The Control Unit is the power entry and distribution point. The 1220
system contains universal power supplies that operate on 100-240 VAC,
50/60Hz. The power switch on the Control Unit switches power for the
entire system. The line is protected by two 3 Amp fuses, accessible from
the front panel.

A 1/8 A fuse is furnished for the electronic circuitry of the Control
Unit. The green power LED indicates that the Unit is ON.

Alarm switch S2 has two positions. Normally, the switch is set to the
ACTIVE position which provides for audible alarm when any of the
Channel Modules goes into the alarm state. When set to the BYPASS
position, the local audible alarm is turned off.

2-2

Teledyne Analytical Instruments

Multi-Channel Combustible Monitor Operational Theory 2

2.4 Channel Module

The Model 1220 Combustible Gas Analyzer uses an Intel Microcon­troller with on-board RAM and ROM to control all signal processing,
input/output, and display functions for the analyzer. The channel power is
supplied from two separate universal power supply modules (100-240
VAC), designed to be compatible with most international power sources.
The first power supply (triple outputs) supplies the voltages for logic
devices. The second power supply (dual outputs) supplies voltage for the
detector(s).

The power supply for the detector is provided with a stable current of
300mA.

Each detector is connected in a bridge circuit with the output signal
feeding an operational amplifier.

A block diagram of the functional relationships of the Channel Module is
shown in Figure 2-3.

2.5 Combustible Sensors

The basic elements of the combustible gas detector are shown in
Figure 2-1. The two beads each consist of a small coil of wire coated with
an appropriate material. The measuring bead coating is a mixture of a
catalytic material with an inert binder. This catalytic material is selected to
enhance the oxidation of combustible gases. The reference bead coating is
an inert material having similar thermal properties to the other bead.

BLACK

REFERENCE

REFERENCE
BEAD

WHITE

MEASURING
BEAD

COMMON

RED

MEASURING

Figure 2-1 Combustible Gas Detector

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2 Operational Theory Model 1220

When exposed to a mixture containing gases and oxygen, the measur­ing bead coating allows the oxygen and combustibles to combine at its
surface. The energy produced by this reaction heats the measuring bead.
The rise in temperature changes the bead’s resistance and is related to the
concentration of the combustible gas. The reaction rate is dependent upon
the nature of the particular combustible gas. Raising the temperature of the
bead increases the reaction rate, which increases the sensitivity of the
sensor and reduces the observed differences of various gases. This rise in
temperature is generated by a constant-current supplied to the sensor.

The temperature of the measuring bead will be influenced by other
factors such as initial gas temperature, gas thermal conductivity, flow rates
and the temperature of its housing. The reference bead, having similar
electrical and thermal properties and being heated by the same current, but
lacking the catalytic material will be similarly affected by these extraneous
factors but not significantly affected by oxidation of the combustible gas.

These two beads are placed in close proximity to one another so that
they are affected by the same environmental factors. Thus the differences
between the changes in resistance of the two coils are directly related to the
concentration of combustible gases.

For area monitoring applications, these two beads are installed in a
metal housing as shown in Figure 2-2. Wires connected to the beads are
brought out the back of the detector through potting which provides me­chanical retention of the wires and provides a gas-tight seal. A stainless­steel flashback arrestor screen at the front of the detector covers the beads
and is held in place by a retaining cylinder pressed onto the housing. This
retaining cylinder is threaded internally to accept a flow-through adapter
for calibration.

INTERNAL THREAD FOR
CALIBRATION ADAPTER

RED

WHITE

BLACK

2-4

3/4 NPT

15/16” WRENCH FLAT

Figure 2-2 Remote Combustible Probe

Teledyne Analytical Instruments

PROBE SENSING

SURFACE

Multi-Channel Combustible Monitor Operational Theory 2

The response of a catalytic bead detector to a number of gases is

shown in Table 1.

For lighter than air gases, the detectors are generally installed above
the source; for heavier than air gases, detectors are generally installed
below the source.

Table 1

Detector Response to Gases

COMPOUND LEL* RESPONSE FACTOR

Methane 5.0 1.00

Hydrogen 4.0 0.86

Carbon Monoxide 12.5 0.32

Ethane 3.0 1.20

Ethylene 2.7 1.26

Acetylene 2.5 1.39

Propane 2.2 1.42

Propylene 2.0 1.33

Butane 1.9 1.54

Hexane 1.1 1.50

Cyclohexane 1.3 1.44

Heptane 1.05 1.59

Benzene 1.3 1.50

Toluene 1.2 1.48

Ethylene Oxide 3.6 0.76

Methyl Ethyl Ketone 1.8 0.96

Methyl Acrylate 2.8 0.59

* Taken from Fire Hazard Properties of Flammable Liquids, Gases
and Volatile Solids, National Fire Protection Agency.

Teledyne Analytical Instruments

2-5

2 Operational Theory Model 1220





S2



± 12 V Test

Power Supply 2

AC/DC

+ 5, ± 15 V Test

S1





M



U
X



Analog Output Test



A to D

Converter

Digital to
Analog
Converter
(DAC)



To CPU



0-10 V dc



Concentration

4-20 mA dc
Concentration

Relays



High

2-6

Keyboard

Display & LED
Indicators

Power Supply 1

AC/DC





Central

Processing

Unit

(CPU)



Figure 2-3: Block Diagram of the Signal Processing Electronics

Teledyne Analytical Instruments

Caution

Failure

RS-485

Multi-Channel Combustible Monitor Operational Theory 2

2.5.1 Response of Combustible Sensor to Various
Gases

Response factors have been determined to relate the sensor output of a
specific compound to the output obtained using methane. A list of some
typical compounds is given in Table 1, along with their LEL (Lower
Explosive Limit) values. To determine the output of the sensor to any of
the gases listed, compared to the same concentration of methane, multiply
the reading obtained by the factor listed.

For example, if the output is calibrated with methane at 2%, the
output for ethylene at 2% would be 2.0% X 1.26 = 2.52% methane equiva­lent.

NOTE: The LEL and the response factors cannot be used directly for

calibration. See Table II on page 4-16 for calibration of the
instrument to gases other than Methane.

CAUTION: In most cases, the concentration of any particular

compound that the sensor is exposed to should
not exceed the LEL of that compound, or sensor
damage could occur.

The concentration of combustibles should never
exceed that which will react completely with the
available oxygen present in the sample
(stoichiometric burning), otherwise “coking” (the
deposition of carbon from incomplete combustion)
will occur at the sensor, and drift and a loss of
sensitivity will result.

CAUTION: Exposing the sensor to lead, silicone, or acidic

gases may damage the sensor.

NOTE: For compounds not listed, consult TAI.

Teledyne Analytical Instruments

2-7

2 Operational Theory Model 1220

2-8

Teledyne Analytical Instruments

Multi-Channel Combustible Monitor Installation 3

Installation

Installation of the analyzer includes:

1. Unpacking the system

2. Mounting the Channel Module and Control Module

3. Making the electrical connections

5. Making the gas connections

6. Testing the installation

3.1 Unpacking the Analyzer

Each TAI Model 1220 Combustible Gas Monitoring System is gener­ally shipped with the channel modules and control module installed.

Since the system is intended as a safety monitor for detecting the
presence of combustible gases in industrial environments, the system
enclosure is normally installed in a safe area, while the remote sensors are
installed at potentially hazardous areas up to 12 thousand feet distant.
Numerous case options are available, however. One optional configuration
involves a purgeable case for installation in hazardous areas. This type of
case, which is maintained under a positive pressure, is purged with com­bustible-free air.

Teledyne Analytical Instruments

3-1

3 Installation Model 1220

3.2 System Chassis

The physical dimensions and mounting hole spacing for the System
Chassis are given on Drawing D-67849. The System Chassis is designed to
fit into a standard 19" rack. It requires 7" panel height and 12.3" depth plus
allowance for cabling behind the panel.

3.2.1 Location

The System Chassis is designed for installation in a NON HAZARD­OUS Environment.

3.2.2 Power

The model 1220 is designed to operate from 100/240VAC @ 50/60
Hz. Ventilation must be provided to dissipate heat generated within the
control unit. Natural convection is sufficient to cool 16 Channel Modules.
However, if more are mounted in the same chassis, forced ventilation should
be used.

3.2.3 Electrical Connections

The primary power terminals are designated H(hot), N (neutral) and
GND (ground). Connections should be made in accordance with these
designations.

All electrical connections are available at the barrier-type terminal strips
located at the rear of the control unit. These facilities are shown on the user
interconnection drawing D-67850.

WARNING: Disconnect primary power before making or

changing connections to any of the terminal
strips.

Relay contact connections are indicated as NC (normally closed), NO
(normally open) and C (common). These designations refer to the contact
state when the relay is de-energized.

Sensor connections are indicated as RD (red), WH (white) and BK
(black). These designations refer to the color of the sensor lead wires.

NOTE: The cable shield should be connected to ground only

at one end of the cable (this applies for each sensor

connection). See Figure 3.1.

3-2

Teledyne Analytical Instruments

Multi-Channel Combustible Monitor Installation 3

Care must be observed to ensure that the sensor leads are not inadvert­ently connected to the signal common (C) or to the power ground while
energized. (See Figure 3-1)

Note: The maximum loop resistance for cabling to each sensor

W

is 35 , i.e. the cabling and connections should not ex­ceed 35 total, or 35 / 2 = 17.5 on each side of the

W

W

W

sensor (See Figure 3-2).
Note that the white wire resistance is not a limiting factor

in the Loop Resistance, i.e. its resistance is not included
in the Loop Resistance measurement. To measure the
Loop Resistance directly, short the RED and BLACK
Connections at the Sensor and measure the resistance
between RED and BLACK at the channel module end of
the cable.

Figure 3-1 Sensors Connections

Teledyne Analytical Instruments

3-3

3 Installation Model 1220

Figure 3-2 Maximum Loop Resistance for Sensor Connection

The terminals marked "Ext. Audible Alarm" provide an external signal
that is activated whenever the audible alarm is activated. By setting jumpers
on the Control Unit PCB (see section 3.3), the external signal can be either
(1) a contact closure, or (2) a powerline level signal.

Reactive loads connected to the relay contacts must be equipped with
appropriate transient suppression networks to prevent spurious triggering of
sensitive alarm circuits.

Analog output from each channel module should be connected to
monitoring equipment as shown in Figure 3-3. Note that the monitoring
equipment inputs should be floating (not grounded). The cable shield should
be connected to ground only at one end of the cable.

3-4

Figure 3-3 Analog Output Connection

Teledyne Analytical Instruments

Multi-Channel Combustible Monitor Installation 3

3.3 Control Unit

In the event that it becomes necessary to remove the Control Unit,
primary power to the System Chassis must first be disconnected, and the six
small screws around the periphery of the Control Unit front panel removed.
The two knurled, slotted jack screws may then be backed out to pull the
Control Unit out until it is disengaged from its socket. It may then be slid out
of the chassis.

Reinstallation of the Control Unit simply requires that it be slid into the
system chassis, making certain that the circuit board lines up with the con­nector. The circuit may be seated in the connector by tightening the jack
screws. The six retaining screws may then be reinstalled and the primary
power reconnected to the System Chassis.

Do not hotswap (remove or install with power on) the chan­nel modules to system chassis. Failure may occur by causing
power shorts while lining up the circuit board with the
backpanel connector.

Install channel modules starting at the end of the system
chassis, working toward the middle to prevent missalignment
problems.

3.3.1 Control Unit Fuses

The Control Unit contains three fuses. Two 3 Amp fuses protect the
entire system (one fuse for Hot, one for Neutral). An independent 1/8 Amp
fuse protects the Control Unit circuitry. To change any of the fuses, twist the
fuse holder knob counterclockwise and slide the holder out until the fuse is
visible, install the new fuse, slide the holder back in, and turn the knob
clockwise.

3.3.2 Control Unit Jumper Settings

The Control Unit may be configured by changing the installation of the
jumpers on the PCB. See the following sections for complete jumper instal­lation information. The default jumper installation is:

Teledyne Analytical Instruments

3-5

3 Installation Model 1220

Three alarms (CAUTION, HIGH, and FAIL) may be configured for

either fail-safe (default) or non-fail-safe operation per the following table:

The external audible alarm may be configured to operate in either the
fail-safe (default) mode or the non-fail-safe mode. It may also be configured
to provide either a contact closure (default) or the incoming line voltage to
the external connections. Additionally, the contact closure can be normally
opened or normally closed (when the relay is de-energized). The following
tables summarize the jumper settings for the external audible alarm configu­rations:

3-6

Teledyne Analytical Instruments

Multi-Channel Combustible Monitor Installation 3

The internal audible alarm may be disabled by removing JP17.

WARNING: It is not recommended to remove JP17 unless

there is an external audible alarm in use. With the
jumper removed, the audible alarm will not warn
personnel about alarm conditions.

3.4 Channel Modules

Channel Modules may be removed by first unscrewing the top (retain­ing) screw and then unscrewing the bottom (jack) screw. As the jack screw
is backed out, it will pull the module from its socket. When the jack screw is
free, the module may be slid out by pulling on the two screws. In the event
it is desired to remove a channel module without disturbing the common
alarm circuits, the channel module may be switched into standby mode, by

pressing the switch, before removal. Reinstallation of the channel

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3 Installation Model 1220

module may be accomplished by sliding the module into the chassis until the
top and bottom screws can be engaged, engaging them, tightening the
bottom (jack) screw to reconnect the module, and then tightening the top
(retaining) screw.

WARNING: Disconnect power before performing any of the

following. These operations should only be per­formed by a qualified service technician.

3.4.1 Removing the Channel Module Cover

In order to perform the actions in the following sections 3.4.2, 3.4.3 and

3.4.4, the cover of the channel module must be removed. To remove the
cover, unscrew the two 6-32 screws that hold the cover in place, then slide
out the cover.

3.4.2 Changing the Fuse

Remove the channel module cover as in section 3.4.1. The fuse is

located as shown in the Figure 3-4

Figure 3-4 Fuse and Sensor PCB Locations

3.4.3 Adding or Removing the Second Sensor PCB

The model 1220 channel module may be configured for operation with
either one or two combustible sensors. Each sensor's power supply resides
on a sensor PCB. The location of the two sensor PCBs is shown in Figure
3-4. The single sensor PCB is factory installed at location SENSOR 1. In
order to use two sensors with a single channel module, an additional sensor
PCB must be installed at location SENSOR 2.

To add or remove the SENSOR 2 PCB, first remove the channel
module cover as in section 3.4.1 and add/remove the second sensor PCB as
shown in Figure 3-4.

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Multi-Channel Combustible Monitor Installation 3

3.4.4 Configuring the Internal Jumper Connections

The Channel Module outputs may be configured by setting the internal
jumpers. In addition there are several factory preset jumpers configured as
shown in the following table. Changing the internal jumpers requires remov­ing the channel module cover as in section 3.4.1.

The Channel Module is configured to provide an RS485 communica­tion link with the Control Unit (not available at this time). This communica­tion link is not compatible with Control Units having the Common Meter. In
order to use the Channel Module with a Control Unit that has a Common
Meter, remove jumpers JP1 and JP3 as indicated in the following table:

Used with Model 1220
With common meter (normal)

Off

Off

Jp1

Jp3

RS485

On

On

The Channel Module can provide one of three forms of output. The
output appears at terminal 16 and 17 of the terminal strip, and is selected by
jumper setting as in the following table:

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3 Installation Model 1220

3.5 Combustible Sensors

The sensors should be mounted with their long axis vertical and the
sensing surface downward. It is recommended that any terminal lugs be
attached to the sensor by soldering as well as by crimping. However, care
must be observed to insure that solder does not flow onto the area where the
terminal screws must seat, as that can make it difficult to get firm, permanent
seating of the screws. If conduits carrying the sensor leads to the control unit
also carry other electrical wiring, the sensor leads must be shielded.

The Channel Modules may support one or two sensors (dual-sensor
option). When the dual-sensor option is used, the two sensors connected to a
Channel Module should monitor related areas. For example, in an area
where wind may cause leaking combustible gases to drift in different direc­tions, the two sensors can be placed on opposite sides of the monitoring area.
Then, in the event of a leak, either of the sensors may activate the Channel
Module alarm.

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Multi-Channel Combustible Monitor Operation 4

Operation

4.1 Introduction

Once the System has been Installed, check all wiring to make certain
that it is correct. Check that the POWER switch on the Control Unit is in
the “OFF” position, then apply primary power to the system. Continue
start-up as follows:

1. Check that AUDIBLE ALARM switch is set to BYPASS mode
on the Control Unit.

2. Set the Control Unit POWER switch to ON. The green power
lamp and red bypass lamp should be illuminated. All the green
Power LEDs on the channel modules should be illuminated.

Each channel goes thru the process of a self-diagnostics test for
the following:

Checks the power supply 5V output
Checks the power supply +/-15V outputs
Checks the power supply +/-12V outputs
Checks the analog outputs
Checks for one sensor or two sensor mode
Checks for sensor installation
Checks that the ADC is responding

3. The Channel Modules are shipped with the ZERO and SPAN
preset, and the alarm setpoints at 50% and 80% LEL (Lower
Explosive Limits). The Channel Module relays revert to normal
state after start-up.

4. After verifying that the Control Unit, and each Channel Module
are operating normally, allow the system to stabilize over a 24
hour period.

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4 Operation Model 1220

4.2 Control Unit Operation

4.2.1 System Power Switch and LED

The power to the entire 1220 system is controlled by the System

Power Switch.

The green System Power LED indicates system power status (ON/

OFF).

4.2.2 Audible Alarm Switch and Bypass LED

The Audible Alarm Switch overrides the audible alarm when in the
Bypass position. The red Bypass LED lights when the audible alarm is
bypassed.

4.2.3 Fuses

For fuse replacement/installation, see section 3.3.1 and 3.4.3

4.2.4 RS485 Port

NOTE: This feature is not presently supported--contact the factory for

application assistance.

An RS485 port is provided at the 9-pin D-sub connector. The RS485
port is connected internally to all of the Channel Modules in the system.

4-2

Control Unit - Front View

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Multi-Channel Combustible Monitor Operation 4

Channel Module Front Panel Controls and Indicators

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4 Operation Model 1220

4.3 Channel Module Front Panel
Controls and Indicators

STANDBY Switch - When pressed, this membrane switch
places the Channel Module in the standby mode, i.e.,
removes power from the sensor(s) and extinguishes the
LCD display.

NOTE: If the relays are configured for fail-safe operation, they will remain

energized. If an alarm condition exists, the Channel Module will
return to a non-alarm state.

RESET Switch - After an alarm condition is no longer

RESET

present, as indicated by the concentration value shown on
the display, press this membrane switch to return the relay
or relays to the non-alarm (normal) state.

BYPASS Switch - When in an alarm condition, pressing

BYPASS

NOTE: The red, yellow and blue alarm LEDs begin to flash. They remain

flashing until the alarms are reset or the BYPASS switch is pressed
again.

SELECT

this membrane switch disables the Control Unit audible
alarm.

SELECT Switch - Use this membrane switch to access any
of the Channel Module’s four user-configurable modes and
their options. The four modes are:

1. Sensor and Calibration Mode - This mode allows you to

select sensor 1 (S1) or sensor 2 (S2) and then set the
ZERO and SPAN values. It also is used during the
“One-Man” (1MAN) calibration option.

2. Alarm Configuration Mode - This mode allows you to

adjust the set points of the High and/or Caution alarms
as well as define the configuration for the alarms as
“Fail-Safe” / “Non-Fail-safe” and/or “Latching” / “Non­Latching”.

3. Identification (ID) Code Set Mode - This mode allows

you to define the unique ID for each Channel Module
for use with RS-485 communication (Special option,
contact factory).

4. Passcode Enable/Disable Mode - This mode allows you

to enable or disable the factory-defined passcode.

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Multi-Channel Combustible Monitor Operation 4

ENTER Switch - Use this membrane switch in

ENTER

RUN

conjunction with the SELECT Switch to select a
user-configurable mode and then the option high­lighted.

RUN Switch - Pressing this membrane switch places
the Channel Module in the analysis mode, i.e., the
unit is operational.

When in one of the four
user-configurable modes, all
arrows allow you to navigate
through the options. In
addition, the Up/Down
arrow keys can be used to set
the values shown on the
display for ZERO and SPAN
and also increase/decrease
the value of the HIGH and
CAUTION alarms.

HIGH ALARM

HIGH ALARM

CAUTION

CAUTION

FAIL

FAIL

POWER

Red LED indicates High alarm condition. Flashes
when bypassed.

Yellow LED indicates Caution alarm condition.
Flashes when bypassed.

Blue LED indicates a Channel Module or Sensor
failure. Flashes when bypassed.

Green LED remains on during operation, turns off
in STANDBY Mode.

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4 Operation Model 1220

NOTE:

When one of these modes
are selected, the field light
flashes indicating which
mode the monitor is on.

Configuration Display Panel Fields

“S1” highlighted indicates that Sensor 1 options may be set.

“S2” highlighted indicates that Sensor 2 options may be set.

This option is used to zero (“0”) calibrate the Channel Module.

This option is used to span calibrate the Channel Module.

This option enables a single person to perform both a span and
zero calibration.

“H” highlighted indicates that the High Alarm value can be set
by using the Up/Down Arrow Keys.

“C” highlighted indicates that the Caution Alarm value can be
set by using the Up/Down Arrow Keys.

When the instrument goes into an alarm condition, the alarm
relay switches. If “LCH” (latched) was selected, the alarm relay
remains switched (latched) even after the alarm condition has
been cleared. Using this configuration, you must press the
RESET switch to unlatch (unlock) the relay.

When the instrument goes into an alarm condition, the alarm
relay switches. If “NLCH” (non-latched) was selected, the
alarm relay switches (unlatches) when the alarm condition is
cleared.

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Multi-Channel Combustible Monitor Operation 4

If “FS” is selected, the associated relay is in the Fail-safe Mode,
i.e., the relay is “normally energized”.

If “NFS” is selected, the associated relay is in the Non-Fail-safe
Mode, i.e., the relay is “normally de-energized”.

Sensitivity Gauge

The Sensitivity Gauge monitors the life of the sensor. It does so
by monitoring successive span procedures throughout the life of
the sensor. As the sensor gets older it’s resistance builds,
lessening the sensitivity.

LCD Display

The LCD Display shows the LEL in monitor (RUN) mode,
alarm settings during the configuration mode, and calibration
values during Span and Zero operations.

4.4 Calibration Procedures

4.4.1 Zero Calibrating a Single Sensor Channel Module

NOTE:

To accomplish the following task, two operators are needed.
Operator one at the Control Unit and operator two at the
probe. Both operators are involved in the calibration process.
They must be in constant communication, by phone or other
means.

(A) = Operator One at the Control Unit
(B) = Operator Two at the probe

1. (A) At the Front Panel of the Channel Module to be calibrated:

a. Press SELECT.
b. Use the right or left arrow key to highlight the ZERO option.
c. Press ENTER.

Result: Alarms are deactivated and the ZERO display
option flashes.

2. (B) Introduce zero gas into the sensor.

3. (A) After the reading has stabilized:

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4 Operation Model 1220

a. Press the up or down arrow key until the display reads “0”.
b. Press ENTER.

4. (B) Disconnect the zero gas from the sensor.

5. (A) If necessary, proceed to the previous or next procedure. Other-

wise, press RUN to place the instrument in the analysis mode.

4.4.2 Span Calibrating a Single Sensor Channel Module

NOTE:

To accomplish the following task, two operators are needed.
Operator one at the Control Unit and operator two at the
probe. Both operators are involved in the calibration process.
They must be in constant communication, by phone or other
means.

(A) = Operator One at the Control Unit
(B) = Operator Two at the probe

1. (A) At the Front Panel of the Channel Module to be calibrated:

a. Press SELECT.
b. Use the right or left arrow key to highlight the SPAN option.
c. Press ENTER.

Result: Alarms are deactivated and the SPAN display
option flashes.

2. (B) Introduce span gas into sensor.

3. (A) After the reading stabilizes:

a. Press the up or down arrow key until the display reads the value

that corresponds to the LEL of the certified span gas used.

NOTE: Information about calibration valves for various com-

bustible gases appears in Table 1 on page 2-5 and in Section

4.11 on page 4-14

4-8

NOTE:

If you need to adjust the Sensitivity Gauge, see Paragraph 4.8
for recommendations.

b. Press ENTER.

4. (B) Disconnect the span gas from the sensor.

5. (A) If necessary, proceed to the previous or next procedure. Other-

wise, press RUN to place the instrument in the analyze mode.

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Multi-Channel Combustible Monitor Operation 4

4.4.3 Zero Calibrating a Dual Sensor Channel Module

NOTE:

To accomplish the following task, two operators are needed.
Operator one at the Control Unit and operator two at the
probe. Both operators are involved in the calibration process.
They must be in constant communication, by phone or other
means.

(A) = Operator One at the Control Unit
(B) = Operator Two at the probe

1. (A) At the Front Panel of the Channel Module to be calibrated:

a. Press SELECT.
b. Use the up or down arrow key to highlight the appropriate

sensor to be calibrated (S1 = Sensor 1 or S2 = Sensor 2).

c. Press ENTER.
d. Perform the procedure listed in Paragraph 4.4.1 beginning with

Step “1b” and then return here.

2. To calibrate the second sensor, perform this procedure again begin­ning with Step “1b”.

4.4.4 Span Calibrating a Dual Sensor Channel Module

NOTE:

To accomplish the following task, two operators are needed.
Operator one at the Control Unit and operator two at the
probe. Both operators are involved in the calibration process.
They must be in constant communication, by phone or other
means.

(A) = Operator One at the Control Unit
(B) = Operator Two at the probe

1. (A) At the Front Panel of the Channel Module to be calibrated:

a. Press SELECT.
b. Use the up or down arrow key to highlight the appropriate

sensor to be calibrated (S1 = Sensor 1 or S2 = Sensor 2).

c. Press ENTER.
d. Perform the procedure listed in Paragraph 4.4.2 beginning with

Step “1b” and then return here.

2. To calibrate the second sensor, perform this procedure again begin­ning with Step “1b”.

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4 Operation Model 1220

4.4.5 Using the “1MAN” Calibration Option

The two following calibration procedure can be performed by one

technician.

4.4.5.1 Zero and Span Calibrating a Single Sensor
Channel Module

1. At the Front Panel of the Channel Module to be calibrated:

a. Press SELECT.
b. Use the right or left arrow key to highlight the 1MAN option.
c. Press ENTER.

2. At the remote probe site, introduce certified span gas to the sensor.

3. Wait 60 seconds so that the reading can stabilize.

4. Remove the span gas and introduce zero gas to the sensor.

5. Wait 60 seconds so that the reading can stabilize.

6. At the Front Panel of the Channel Module being calibrated:

a. Press the up or down arrow key until the display reads “0”.
b. Press ENTER.
c. Press the up or down arrow key until the display reads the value

that corresponds to the value of the certified span gas used.

NOTE: Information about calibration values for various combustible

gases appears in Table 1 on page 2-5 and in Section 4.11 on page
4-14

NOTE:

If you need to adjust the Sensitivity Gauge, see Paragraph 4.8

for recommendations.

d. Press ENTER.

7. If necessary, proceed to the previous or next procedure. Otherwise,

press RUN to place the instrument in the analysis mode.

4.4.5.2 Zero and Span Calibrating a Dual Sensor Channel
Module

1. At the Front Panel of the Channel Module to be calibrated:

a. Press SELECT.
b. Use the up or down arrow key to highlight the appropriate

sensor to be calibrated (S1 = Sensor 1 or S2 = Sensor 2).
c. Press ENTER.
d. Use the right or left arrow key to highlight the 1MAN option.
e. Press ENTER.
f. Perform the procedure listed in Paragraph 4.4.5.1 beginning

with Step “2” and then return here.

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Multi-Channel Combustible Monitor Operation 4

2. To calibrate the second sensor, perform this procedure again begin­ning with Step “1b”.

4.5 Alarm Configuration Procedures

4.5.1 Defining the Setpoint for the High or Caution Alarm

NOTE:

(Applies to Dual Sensor Instruments Only)

Caution Alarm relays are shared by both sensors, i.e., only
one setpoint for the High Alarm and one setpoint for the
Caution Alarm can be defined.

The High and

1. At the Front Panel of the Channel Module to be configured:
a. Press SELECT twice to enter the “Alarm Configuration”

Mode. (“H” {High} will be flashing.)

b. Use the up or down arrow key to highlight the appropriate alarm

to be defined (“H” = High Alarm or “C” = Caution Alarm).

c. Press ENTER to select the alarm.
d. Use the up or down arrow key to adjust the displayed value to

the desired percentage for the alarm selected.

e. Press ENTER.

2. If necessary, proceed to the previous or next procedure. Otherwise,
press RUN to place the instrument in the analysis mode.

4.5.2 Configuring Alarm Relay Settings

4.5.2.1 Setting the Fail-safe or Non-Fail-safe Mode

1. At the Front Panel of the Channel Module to be configured:
a. Press SELECT twice to enter the “Alarm Configuration”

Mode. (“H” {High} will be flashing.)

b. Use the up or down arrow key to highlight the appropriate alarm

to be defined (“H” = High Alarm or “C” = Caution Alarm).
c. Use the left or right arrow key to highlight the “FS” option.
d. Press ENTER.
e. Use the up or down arrow key to switch to the desired configu-

ration for the alarm (“FS” = Fail-safe and “NFS” = Non-Fail-

safe.)
f. Press ENTER.

2. If necessary, proceed to the previous or next procedure. Otherwise,

press RUN to place the instrument in the analysis mode.

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4 Operation Model 1220

4.5.2.2 Setting the Latching or Non-Latching Mode

1. At the Front Panel of the Channel Module to be configured:

a. Press SELECT twice to enter the “Alarm Configuration”

Mode. (“H” {High} will be flashing.)

b. Use the up or down arrow key to highlight the appropriate alarm

to be defined (“H” = High Alarm or “C” = Caution Alarm).
c. Use the left or right arrow key to highlight the “LCH” option.
d. Press ENTER.
e. Use the up or down arrow key to switch to the desired configu-

ration for the alarm (“LCH” = Latching and “NLCH” = Non-

Latching.)
f. Press ENTER.

2. If necessary, proceed to the previous or next procedure. Otherwise,

press RUN to place the instrument in the analysis mode.

4.6 Setting the ID Code

1. At the Front Panel of the Channel Module to be configured:

a. Press SELECT three times to enter the “ID Code” Mode. (The

current ID code will be displayed.)
b. Press ENTER.
c. Use the left and right arrow key to select the digit to be modi-

fied and the up and down arrow keys to modify the selected

digit.
d. Repeat Step “c” to modify the remaining digits.
e. Press ENTER to save the ID Code.

2. If necessary, proceed to the previous or next procedure. Otherwise,

press RUN to place the instrument in the analysis mode.

4.7 Enabling/Disabling the Pass Code

1. At the Front Panel of the Channel Module to be configured:

a. Press SELECT four times to enter the “Pass Code” Mode.

(The current pass code state {“Poff” = Passcode off or “P on”

= Passcode on} will be displayed.)
b. Press ENTER.
c. Use the up or down arrow key to modify the state of the code.
d. Press ENTER to accept the change.

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Multi-Channel Combustible Monitor Operation 4

2. If necessary, proceed to the previous or next procedure. Otherwise,

press RUN to place the instrument in the analysis mode.
Passcode: Press the Down arrow key followed by the Right arrow key.

4.8 Setting the Sensitivity Gauge

NOTE: The sensitivity gauge can only be adjusted when performing a

local (Paragraph 4.3) or “1MAN” (Paragraph 4.4.5.1) span
calibration.

Recommendations:

1. Upon initial installation of a new sensor, use the left or right arrow

key to set the gauge to read “100”.

2. Each time that you complete a span calibration procedure, the value
of the sensitivity gauge will be updated to indicate the sensor’s
sensitivity (measured relative to its original sensitivity). This can
be used as an estimate of the sensor’s remaining life.

4.9 Routine Operation

During routine operation, the system will require no attention unless
an alarm state occurs. In the event of an alarm indication, the audible
alarm may be silenced in one of two ways:

1. Move the AUDIBLE ALARM switch on the system control mod­ule to BYPASS. This will immediately silence the audible
alarm and also prevent an audible indication from occurring should
another channel go into an alarm state.

2. Press the BYPASS button on the Channel Module. The associated
alarm LED will flash and the AUDIBLE ALARM will be silenced
until the ALARM condition is cleared. In this case, only the
specific alarm channel will be affected. In the occurrence of an
additional alarm in the same channel, or any alarm in any other
channel, the AUDIBLE ALARM will again activate.

In either case, once the audible alarm has been silenced the combusti­ble gas level may be determined by viewing the LCD display reading on
the channel module. When the level has diminished to less than the alarm
level, the system may be reset by depressing the RESET button.

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4 Operation Model 1220

4.10 FAIL Alarm Conditions

The possible FAIL Alarm Conditions are:

- A sensor fails.

- One of the power suppliers fails.

- 0-10V Output fails.

- The ADC times out without a proper end-of-conversion (EOC).

Whenever a failure is detected, the FAIL alarm is activated: the blue
LED turns on, the alarm relay is de-energized (the FAIL relay is FAIL­SAFE, and the audible alarm is activated. The power supplies to both
sensors are disabled.

Failure alarms are accompanied with a FAIL code number. The
display alternates between “FAIL” and the code number.

The failure alarm may be bypassed (by pressing the Bypass Button),
in which case, the blue LED flashes, and the audible alarm is deactivated.

To acknowledge a failure condition, press RESET. This restarts the
instrument (as if the button has been pressed twice). Alternatively, you
may turn the unit OFF using the button.

NOTE: The reason the failure modes require restarting the instru-

ment is that once a failure has been detected, the unit should
not be used until the error is fixed.

When a failure alarm is detected, the other two alarms (caution and
high) are disabled.

4.11 Calibration of Combustible Gas Detectors to the
LEL of Gases other than Methane

The lower explosive limit (LEL) varies substantially between the
different explosive gases. It is, therefore, necessary to consider the LEL of
a particular gas as well as the relative response of a detector to this gas in
order to calibrate the detector to indicate the concentration as a percentage
of the LEL. The most commonly used calibration gas contains small

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Multi-Channel Combustible Monitor Operation 4

amounts (percentages) of methane mixed with air. Table II lists calibration
factors for the TAI Combustible gas sensor which can be used to calibrate
these detectors to indicate the percent LEL of the specific gases. These
calibration factors are based on the use of methane in the air as the calibra­tion gas and take into account both relative response and LEL of the
specific gases.

To use these calibration factors, multiply the percent volumeric
concentration of methane in the calibration gas by the appropriate calibra­tion factor. The number thus obtained is the meter reading to which the
instrument should be spanned, in accordance with the calibration proce­dures, when the sensor is exposed to the calibration gas. When so adjust­ed, the instrument will be calibrated to indicate the percent LEL of the
selected gas.

Use the following formula to determine the value to enter during the
span calibration procedure:

V = CH4 x CF

Where:

V = Value to enter during span calibration

CH4 = Percent methane in air

CF = Calibration Factor from Table II

EXAMPLE:

CH4 = Certified Calibration Gas = 2.2% methane in air

Gas for which calibration is desired = Ethane

CF = Calibration Factor from Table II = 28

V = Calibration Meter Reading = 62 = 2.2 X 28

Using the calibration procedures in this manual, adjust the span so
that with calibration gas flowing through the calibration adapter, a meter
reading of 62 is obtained. The instrument will then be calibrated to indi­cate 0 to 100% LEL of Ethane.

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4 Operation Model 1220

TABLE II

Calibration Factors for TAI Combustible Gas Sensor

COMPOUND CALIBRATION FACTOR
Methane 20

Hydrogen 29
Carbon Monoxide 25
Ethane 28
Ethylene 29
Acetylene 29
Propane 32
Propylene 38
Butane 34
Cyclohexane 53
Heptane 60
Pentane 46
Toluene 56
Ethylene Oxide 37
Methyl Ethyl Ketone 58
Methyl Acrylate 61
Hexane 61

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Multi-Channel Combustible Monitor Failure and Error Codes 5

Failure and Error Codes

5.1 Failure Codes

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5 Failure and Error Codes Model 1220

5.2 Error Codes

5-2

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Multi-Channel Combustible Monitor Appendix

Appendix

A-1 Specification

Range: 0-100% LEL Combustible Gas in Air

(Methane equivalent)

Number of Channels: Up to eight channels

Repeatability: 2 % of full scale

Accuracy: ±2% of full scale at constant tempera-

ture

Response Time: 90% in less than 15 seconds

Operating Temperature: 0 to 50oC

Temperature Stability: ±1% over 10oF

Alarms: Two Adjustable Alarm Point plus

Failure Alarm Indicators illuminate at
Alarm Setpoint. HIGH-RED;
CAUTION-AMBER; FAIL-BLUE.

Sensor Type: Two element catalytic bead, anodized

aluminum housing, Stainless Steel
(Flame Arrestors)

Signal Output: Internal: LCD Display

External: 0-10 VDC or 4-20 mA
negative ground (user-configurable)

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Appendix Model 1220

Power Requirements: 100-240 VAC 50/60 Hz

System Enclosure: Control Module fits standard 19”

Relay Rack

Dimensions: 7” H x 12.3” D x 19” W

Maximum Loop Resistance for
Sensor Connections/Cabling: 35

W

Maximum Loop Resistance
for 4-20 mA OUTPUT: 600

W

Sensor Probe Mounting: 2 MTG. Holes , 3/16” Diameter, 2 3/

8”

C-TO-C (custom probes for special
applications).

Field Connections: Barrier-Type Terminal Strips with

screw connections.

Alarm Output: Form “C” Relay Contacts (SPDT)

Recommended Spare Parts List

Qty Part Number Description

2 A-12698 Adapter, Flow-Thru
10 A-11091 Adapter, Female
4 B-12093 Detector
5 F-1374 Fuse, Type 3AG, 1/8A
10 F-229 Fuse, Micro, 2A
5 F-1379 Fuse, Type 3AG, 3A
1 C-65446 PCB, Front Panel Display
1 C-67479 PCB, Constant Current Supply
1 C-65446 PCB, Front Panel
1 C-66910 Front Panel With Membrane

_____________________

A minimum charge is applicable to spare parts orders.

Note: Orders for replacement parts should include the part number (if

available) and the model and serial number of the instrument for
which the parts are intended.

A-2

Teledyne Analytical Instruments

Multi-Channel Combustible Monitor Appendix

Orders should be sent to:

TELEDYNE Analytical Instruments

16830 Chestnut Street
City of Industry, CA 91749-1580

Phone [phone], Fax [phone]
TWX [phone] TDYANYL COID

Web: www.teledyne-ai.com

or your local representative.

Drawing List

C-67019 Outline Drawing, Control Unit
A-13450 Outline Drawing, Sensing Detector
B-68172 Interconnection Diagram, Model 1220
C-67478 Schematic Diagram, Constant current supply
D-65445 Schematic Diagram, Model 1220 Front Panel Display
D-65442 Schematic Diagram, Model 1220 Main PCB

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Appendix Model 1220

A-4

Teledyne Analytical Instruments