Sensidyne SENSALARM FLEX User manual

Document No. 360-0257-01 (Rev A)

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P a g e 2 | 82 Sensidyne Document No. 360-0257-01 (Rev A)
How to Use This Manual
This manual is a basic guide for using the SensAlarm Flex Universal Gas Monitoring System. It contains
information on SensAlarm Flex components, sensor types, Graphical User Interface, and user
interactions. It also details elements such as how to mount and wire the Universal Gas Monitoring
System, setup, zero, and span calibration. In addition, it covers commonly used operations regarding
alarms, relays, and Test-On-Demand.
Important notes, cautions, and warnings are highlighted from the other text as follows:
NOTE: Relevant Text
WARNING: Relevant Text
CAUTION: Relevant Text and Related Symbol
Basic Menu Controls Guide
The SensAlarm Flex Graphical User Interface is navigated by a non-intrusive magnetic interface. Users
select actions by moving a magnet over the six (6) different front panel functions, which are Escape
(ESC), Up, Down, Left, Right, and Enter.
Selecting Enter from the Normal Operation Display enters the
SensAlarm Flex menu system. Within the main menu, the user will
arrow to select System or Sensor menu options. Enter is then used
to further drill down to the desired submenu options, and to accept
changes made. Escape (ESC) is similar in use to an ESC key on a
computer keyboard, which exits the selection without changes, and
reverts the user to the previous menu option. To return to the
Normal Operational Display, ESC is selected until the display is
revealed.
NOTE:
This manual contains illustrations of display screen menu options generally used in the setup and
operation of the SensAlarm Flex Universal Gas Monitoring System. The Gas Monitoring System may
also display a variety of additional warning or cautionary screens. These additional display screens are
instructive and intuitive in nature. The user should read each displayed screen and perform the
recommended actions as required.
IMPORTANT: Factory Default Settings
Each Universal Gas Monitor is shipped from the factory with default settings. These include default
settings for alarms, faults, strobes, horn, and relays. The default settings can be found in Section X.
Please note that boxes filled with an “X” indicate a default setting for that particular alarm, fault, strobe,
horn, or relay. Additional blank copies of the Configuration Reference form can be found in Section X.
These blank forms are intended for use by the user to document user-defined changes from the factory
default settings.

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Table of Contents
How to Use This Manual...............................................................................................................................2
Packing List and Notices...............................................................................................................................6
1. INTRODUCTION ...................................................................................................................................9
1.1. Product Versions ............................................................................................................................9
1.2. Standard Features........................................................................................................................11
1.2.1. Universal Sensor Capability ..................................................................................................11
1.2.2. Large Display for Ease of Operation.....................................................................................11
1.2.3. Non-Intrusive Operation ........................................................................................................11
1.2.4. Transportable Calibration......................................................................................................11
1.2.5. Predictive Sensor Failure ......................................................................................................11
1.2.6. AC & External DC Power Compatibility.................................................................................11
1.2.7. Communication Protocols .....................................................................................................11
1.2.8. Relay Outputs........................................................................................................................12
1.3. Factory Installed Options..............................................................................................................12
1.3.1. Second Sensor Interface.......................................................................................................12
1.3.2. Remote Sensors....................................................................................................................12
1.3.3. Test-On-Demand tm Gas Generator.....................................................................................12
1.3.4. Stack Strobe Lights ...............................................................................................................12
1.3.5. Internal Battery Backup.........................................................................................................12
1.3.6. Additional Relay Outputs.......................................................................................................13
1.4. SensAlarm Flex Components.......................................................................................................13
1.4.1. Sensor Interface Assembly ...................................................................................................13
1.4.2. Plus Series Sensor................................................................................................................13
1.4.3. Test-on-Demand....................................................................................................................13
1.4.4. Sensor Holder........................................................................................................................13
1.4.5. Rainshield & Moisture Barrier................................................................................................13
1.4.6. Calibration Plug.....................................................................................................................13
1.4.7. Relays....................................................................................................................................14
1.4.8. Modbus..................................................................................................................................15
1.4.9. 4 to 20 mA Output .................................................................................................................16
1.4.10. Battery Backup...................................................................................................................17
1.4.11. Horn and Silence Pushbutton............................................................................................18
1.4.12. Front Panel LED Strobe.....................................................................................................19
1.4.13. Stack Light.........................................................................................................................19
1.4.14. SensAlarm Flex Components (Summary).........................................................................20

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1.4.15. Display (Main Screen) .......................................................................................................21
1.4.16. Sensor Types.....................................................................................................................21
2. INSTALLATION ...................................................................................................................................23
2.1. Location ........................................................................................................................................23
2.2. Code Compliance.........................................................................................................................23
2.3. Gas Monitor Installation................................................................................................................23
2.3.1. AC Power ..............................................................................................................................25
2.3.2. DC Power..............................................................................................................................25
2.3.3. 4 to 20 mA.............................................................................................................................27
2.3.4. Relays....................................................................................................................................27
2.3.5. Modbus..................................................................................................................................28
2.3.6. Field Wire Terminating Locations (Summary).......................................................................30
3. STARTUP ............................................................................................................................................31
3.1. Power On......................................................................................................................................31
3.2. Sensor Installation........................................................................................................................32
4. OPERATING FUNCTIONS..................................................................................................................33
4.1. Calibration.....................................................................................................................................33
4.2. Zero Calibration ............................................................................................................................35
4.3. Span Calibration...........................................................................................................................37
4.3.1. Sensor Adjustment................................................................................................................37
4.3.2. Set Cal Gas Conc. (Concentration).......................................................................................38
4.3.3. Calibrate................................................................................................................................38
4.4. Test-on-Demand™ (ToD).............................................................................................................39
5. ALARMS, FAULTS AND RELAYS ......................................................................................................42
5.1. Alarms...........................................................................................................................................42
5.2. Faults............................................................................................................................................44
5.3. Relays...........................................................................................................................................47
5.4. Strobes .........................................................................................................................................50
6. CONFIGURATION...............................................................................................................................52
6.1. 4 to 20mA Adjustment ..................................................................................................................52
6.2. Communication Setup ..................................................................................................................54
6.2.8. Modbus Register Types and Locations.................................................................................57
6.3. Menu Structure.............................................................................................................................60
6.3.1. System Menu.........................................................................................................................60
6.3.2. SYSTEM CONFIGURATION (Submenus)............................................................................61
6.3.3. CHANNEL CONFIGURATION (Sensor CH-1 & CH-2 Submenus) ......................................69
7. APPENDIX A: DECLARATION OF CONFORMITY ............................................................................70

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8. APPENDIX B: SPECIFICATIONS.......................................................................................................71
9. APPENDIX C: TROUBLESHOOTING GUIDE ....................................................................................72
10. APPENDIX D: TUV CERTIFICATION..............................................................................................74
11. APPENDIX E: RETURNED MATERIAL AUTHORIZATION (RMA) ................................................76
12. APPENDIX F: CONFIGURATION REFERENCE ............................................................................77

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Packing List and Notices
Each SensAlarm Flex Universal Gas Monitoring System includes:
SensAlarm Flex Universal Gas Monitoring System User Manual (this document)
The SensAlert Plus Sensor datasheet for selected sensors
A reversible screwdriver with magnetic wand
(SensAlert Plus Sensors sold separately)
If you have any questions, need assistance, or are missing any of the above items, please contact your
Sensidyne Manufacturer Representative, or contact Sensidyne Customer Support at 800-451-9444 or
[phone].
PROPRIETARY NOTICE
This manual was prepared by Sensidyne, LP exclusively for owners of the SensAlarm Flex Universal Gas
Monitoring System. The information within this manual is proprietary property of Sensidyne, LP and is to
be used only to understand and operate the instrument. By receiving this document, the recipient agrees
that neither this document, nor the information disclosed within, nor any part shall be reproduced or
transferred, physically, electronically or in any form, or used or disclosed to others for manufacturing, or
for any other purpose except as specifically authorized in writing by Sensidyne, LP.
COPYRIGHT NOTICE
© 2020, Sensidyne, LP, all rights reserved. Information contained in this document is protected by
copyright. No part of this document may be photocopied, reproduced, or translated to another program or
system without prior written authorization from Sensidyne, LP.
TRADEMARK NOTICE
Sensidyne, the Sensidyne logo, SensAlert, SensAlarm, SensAlarm Flex, SensAlert Plus logos, and Test-
on-Demand (ToD) are registered trademarks of Sensidyne, LP. The trademarks and service marks of
Sensidyne, LP are protected through use and registration in the United States of America.
SOFTWARE LICENSE
The software included with the SensAlarm Flex Universal Gas Monitoring System is the property of
Sensidyne, LP and shall remain the property of Sensidyne, LP in perpetuity. The software is protected by
U.S. and international copyright laws and is licensed for specific use with the SensAlarm Flex Universal
Gas Monitoring System. Neither the user nor owner may reverse-engineer, disassemble, decompile, or
make any attempt to discover the source code of the software. The software may not be translated,
copied, merged or modified in any way. Neither the user nor owner may sublicense, rent, or lease any
portion of the software. The right to use the software terminates automatically if any part of this license is
violated.
DISCLAIMER
SENSIDYNE, LP ASSUMES NO RESPONSIBILITY WHATSOEVER, TO ANY PARTY WHOSOEVER,
FOR ANY PROPERTY DAMAGE, PERSONAL INJURY, OR DEATH CAUSED BY OR RESULTING
FROM, IN WHOLE, OR IN PART, THE IMPROPER USE, INSTALLATION, OR STORAGE OF THIS
PRODUCT BY THE USER, PERSON, FIRM, ENTITY, CORPORATION OR PARTY NOT ADHERING TO
THE INSTRUCTIONS AND WARNINGS OR NOT ADHERING TO ALL FEDERAL, STATE, AND LOCAL
ENVIRONMENTAL AND OCCUPATIONAL HEALTH AND SAFETY LAWS AND REGULATIONS.

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THE SELLER SHALL NOT BE LIABLE FOR DIRECT, INDIRECT, CONSEQUENTIAL, INCIDENTAL OR
OTHER DAMAGES RESULTING FROM THE SALE AND USE OF ANY GOODS AND SELLER’S
LIABILITY HEREUNDER SHALL BE LIMITED TO REPAIR OR REPLACEMENT OF ANY GOODS
FOUND DEFECTIVE. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR USE OR FOR A PARTICULAR PURPOSE WHICH ARE EXPRESSLY
DISCLAIMED.
WARNING: READ AND UNDERSTAND ALL WARNINGS AND INSTRUCTIONS BEFORE USE
Failure to read, understand, and comply with ALL accompanying literature, instructions, product
labels, and warnings may result in property damage, severe personal injury, or death.
Product is tested and calibrated at the factory prior to shipment. However, this product must be calibrated
prior to initial use and at regular intervals in accordance with this User Manual to ensure proper operation.
Failure to calibrate and operate this product in accordance with this User Manual may result in the
malfunction of the product.
Read and understand ALL applicable federal, state, and local environmental health and safety laws and
regulations, including OSHA. Ensure complete compliance with ALL applicable laws, codes, and
regulations before and during use of this product.
The owner, user, and installer must understand Hazardous Area Protection Concepts and Area
Classifications associated with their application.
UNDER NO CIRCUMSTANCES should this product be used except by qualified or certified, trained,
technically competent personnel, and not until the warnings, user manual, labels, and other literature
accompanying this product have been read and understood.
ALWAYS wash your hands thoroughly after handling, calibrating, or servicing this product.
ALWAYS wear eye protection, such as safety goggles or a face shield, chemically resistant gloves, and
chemically resistant clothing when handling chemicals, or calibration gas standard sources.
DO NOT get chemicals, gases, fumes, or vapors in your eyes or on your skin, as they may cause severe
burns to skin and eyes. If chemicals, gases, fumes, or vapors get in your eyes or on your skin, wash the
affected area thoroughly with water and seek immediately medical attention.
ALWAYS avoid contact with acids to your skin or eyes. Seek immediate medical attention for any contact
with acids.
ALWAYS calibrate in a well-ventilated area. Adequate precautions should be taken to prevent the
buildup of ANY calibration sources or vapors. Avoid breathing ANY calibration fumes or vapors as they
may be hazardous to your health.
ALWAYS dispose of chemicals and calibration sources in compliance with ALL applicable safety laws,
codes, regulations, and guidelines for proper disposal. Failure to do so may result in environmental
damage, property damage, personal injury or death.
ALWAYS close ALL containers of chemicals used with this product after use.
ALWAYS ensure that any compressed calibration substance sources are empty prior to disposal.
ALWAYS use clean, dry, inert materials to contain and / or transfer substances used for calibration.
DO NOT remove, cover, or alter any label or tag on this product, its accessories, or related products.

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DO NOT operate this product should it malfunction or require repair. Operation of a malfunctioning
product or a product requiring repair may result in property damage, serious personal injury or death.
DO NOT attempt to repair or modify this product, except as specified in the User Manual. If repair is
necessary, contact the Sensidyne Service Department to arrange for a Returned Material Authorization
(RMA) (See APPENDIX E: RETURNED MATERIAL AUTHORIZATION for details).
ALWAYS operate this product in the manner intended. Failure to do so may result in property damage,
serious personal injury or death.
Users should ALWAYS refer to MSDS and suppliers’ instructions for proper safety instructions and
handling for any chemicals used with this equipment.
Use ONLY genuine SENSIDYNE® replacement parts when performing any maintenance procedures
described in this manual. Failure to do so may seriously impair the instrument performance. Repair or
alteration of the product beyond the scope of these maintenance instructions, or by anyone other than an
authorized SENSIDYNE® service technician, may cause the product to fail to function as designed, and
persons who rely on this product for their safety could sustain severe personal injury or death.
The SensAlarm Flex Universal Gas Monitoring System is an ambient air monitoring device. Restricting
the access of ambient air to the sensor may result in less than optimal monitoring performance.
Prolonged exposure to excessively high concentrations of Toxic gas may cause the sensor to produce
erroneous readings.
ALWAYS make use of genuine Sensidyne accessories, such as Rainshields, Splashguards, or
Calibration Adapters to protect against variations caused by environmental conditions. Note that reactive
Gases such as ETO, HF, HCN, NO2, SO2, HCl, ClO2, or Cl2 may require special considerations in use
with certain Sensidyne accessories.
ALWAYS Perform tests only within the specified operating ranges.
Sudden changes in pressure may cause temporary fluctuations in the sensor reading.
Sensors should be hot-swapped only when the Normal Operation Mode screen is displayed.
CAUTION: Failure to read and understand the User Manual may result in property damage,
severe personal injury or death.
CAUTION: Risk of electric shock if front cover is opened.
Important Calibration Considerations:
Verify the concentration of calibration gas standard before making calibration adjustments.
The concentration can be altered by:
Deterioration of the gas concentration during storage due to shelf-life.
Interaction of the calibration gas standard with incompatible materials used to contain and
transfer the gas (tubing), absorption onto or permeation through certain plastics, polymers or
elastomers.
Interaction of the calibration gas standard with ambient contaminants, such as water.
If further translation is required, please contact the Sensidyne EU Authorized Representative (see Back
Cover for contact information) or Sensidyne Customer Support at 800-451-9444 or [phone].

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1. INTRODUCTION
This User Manual provides specific information concerning the installation, operation, calibration, and
maintenance of the SensAlarm Flex Universal Gas Monitoring System.
The SensAlarm Flex is a “flexible” and highly configurable Universal Gas Monitoring System, which
includes the standard incorporation of an integral front panel LED normal / alarm / fault strobe, audible
95dB horn, single sensor interface, four (4) relays, 4 to 20mA output, and Modbus RTU and TCP
protocols. Options include a second sensor interface, one (1) to four (4) tier light stack, additional four (4)
relays, battery backup, remote sensor kits, and many accessories for environmental protection and
calibration accommodations. This product is perfectly suited for use in areas or facilities where control
systems do not exist, and can facilitate multiple functional shutdowns or alarm notifications. Due to the
“All-In-One” Universal Gas Monitoring System, the SensAlarm Flex substantially reduces the cost to
facilitate these types of functional requirements. Where control systems do exist, the SensAlarm Flex
facilitates these necessary functions, which allows the owner to avoid additional costs for annunciation
and specific distributed intelligent control components, while providing the necessary interface with the
facility control system. Some of the areas of interest may include, laboratory spaces, confined or secure
areas, welding booths or personnel control centers.
SensAlarm Flex is capable of detecting the presence of potentially hazardous concentrations of
Combustible vapors and gases, Toxic gases and Oxygen deficiency through the use of Plus Series
Sensors, which are transportable sensors with onboard calibration records and historical exposure
records. Sensidyne Manufacturer Representative or Sensidyne Customer Support can assist in
identifying the appropriate sensor for customer applications.
1.1. Product Versions
The configuration of the SensAlarm Flex is part number specific. See the below configuration table for
reference.

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SensAlarm Flex
8
2
0
-
1
8
-
-
R
0
No Battery / No Relay Card
1
No Battery / One Relay Card
2
No Battery / Two Relay Card
3
Battery Back-up / One Relay Card
4
Battery Back-up / Two Relay Card
0
No Lights
1
GP Light Stack
2
Div2 Light Stack
00
No Stack Light
01
Green
No
No
No
02
Blue
No
No
No
03
Amber
No
No
No
04
Red
No
No
No
05
Green
Blue
No
No
06
Green
Amber
No
No
07
Green
Red
No
No
08
Blue
Amber
No
No
09
Blue
Red
No
No
10
Amber
Red
No
No
11
Green
Blue
Amber
No
12
Green
Blue
Red
No
13
Green
Amber
Red
No
14
Blue
Amber
Red
No
15
Green
Blue
Amber
Red
1
Alum Local
2
Alum Remote
3
PVC Local
4
PVC Remote
5
SST Local
6
SST Remote
9
Special Instructions
0
No CH2 Interface
1
Alum Local
2
Alum Remote
3
PVC Local
4
PVC Remote
5
SST Local
6
SST Remote
9
Special Instructions

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1.2. Standard Features
1.2.1. Universal Sensor Capability
The SensAlarm Flex accepts a variety of Plus Series Sensor technologies, which include electrochemical,
catalytic bead, and infrared. Sensors can be installed without having to reconfigure or modify the Gas
Monitor in any way. When a different Plus Series Sensor is installed in the Gas Monitor the unit
reconfigures the system functions to match those of the new sensor. This includes changing all alarm
and calibration settings to match those of the new sensor.
1.2.2. Large Display for Ease of Operation
The SensAlarm Flex has a large seven (7) inch LED display for gas concentration and sensor / system
notifications. The top section is reserved to display a large one and three quarter inch (1 ¾”) gas
concentration for the highlighted sensor channel, which can be seen from several feet away. Sensor
channels one (1) and two (2) are indicated in the bottom left and right sections of the display accordingly.
A blue frame around the sensor channel indicates the selected channel for the top large concentration
display.
1.2.3. Non-Intrusive Operation
Six (6) magnetic hall effect switches bellow the display allow full configuration, calibrations and other
functions to be performed without opening the Monitor enclosure. A magnetic screwdriver is provided
with the Monitor. Access can be password protected to prevent unauthorized access or changes.
1.2.4. Transportable Calibration
Plus Series Sensors have transportable calibration capabilities. Sensors may be calibrated remotely in a
shop or at Sensidyne to be installed at the Gas Monitor without any special tools or adjustments. When a
new sensor is installed, the Gas Monitor automatically adjusts to recognize the new gas type and range
and adjusts system function accordingly.
1.2.5. Predictive Sensor Failure
Predictive Failure is a unique feature that provides the user with an early warning of the pending
expiration of a sensor. When the sensor has less than 10% of its life remaining, a warning can be
configured to appear on the main display, and can be assigned to activate other fault indicators and
output protocols.
Predictive failure is based on sensor age, power on hours, calibration gain and cumulative gas exposure.
The user can access Remaining Sensor Life (percent) at any time.
1.2.6. AC & External DC Power Compatibility
SensAlarm Flex has an internal power supply for operation from 100-240 VAC, 50/60 Hz and rated at 24
VDC, 65 watts output. 24 VDC is used to power the annunciation, so that the Gas Monitor is fully
functional on external 24 VDC or internal battery backup when optionally furnished.
The optional, internal battery backup will power the unit in the event of a line power failure. It
provides 30 minutes operation in full alarm and 60 minutes minimum when not in alarm.
1.2.7. Communication Protocols
The Gas Monitor comes standard with 4 to 20mA output, Modbus RS-485 RTU and Ethernet TCP
protocols.

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1.2.8. Relay Outputs
Four (4) Single Pole, Double Throw (SPDT) 5A relays are standard in SensAlarm Flex. The Relay
Printed Circuit Assembly (PCA) inside the Gas Monitor includes LED lights for indication of individual
relay activations.
1.3. Factory Installed Options
1.3.1. Second Sensor Interface
SensAlert Flex permits an optional second sensor interface to be installed in the channel-2 or on the right
of the Gas Monitor. Just as with the standard channel-1 left sensor interface, any Plus Series Sensor can
be utilized in this additional channel location. SensAlert Flex sensor interfaces are intrinsically safe,
which permits a faster response with target gases in the atmosphere due to the unneeded use of physical
barriers, such as sintered metal disks to protect the sensor or internal electronics from potentially
hazardous environments.
1.3.2. Remote Sensors
One or both sensor interfaces can be remote mounted up to one-hundred (100) feet away from the gas
monitor. This “flexibility” permits the detection of heavier or lighter than air target gases, and the use of
special fixturing such as with use with the Sensidyne Hazardous Area Approved Sample Draw or duct
mounting.
The sensor interface is connected without special cable or conduit. Sensidyne furnishes all hardware to
remote mount the sensor.
1.3.3. Test-On-Demand tm Gas Generator
The Gas Monitor Test On-Demand™ (ToD) feature allows the gas sensor response to be confirmed
quickly and easily. When activated, either manually, or at programmed intervals, the ToD™ cell, which
resides in the sensor interface, generates a small gas output which interacts with the gas sensor to verify
that it is responsive to gas. This un-manned “bump test” does not replace recommended calibration
procedures. The purpose of this feature is to provide a higher level of system operating confidence by
confirming that the sensor responds to gas. Environmental conditions or ToD cell depletion can cause
this test to be degraded or fail. A low mA signal for 30 seconds will indicate failure or a fault output may
also be assigned.
1.3.4. Stack Strobe Lights
SensAlarm Flex offers an optional stack light assembly where 360° alarm / fault visual indication is
required. The stack light can be configured with up to four (4) visual indicators, which include red, amber,
blue and green. The stack light will follow the visual indication of the front panel LED strobe and can be
configured to remain steady or flash.
1.3.5. Internal Battery Backup
An integral battery backup option with internal charging is offered to sustain SensAlarm Flex operational
functionality in the event of power outage. If a gas alarm occurs during battery backup, a minimum of 30
minutes operation is available. The Gas Monitor will operate for longer periods of time if no alarms are
present, and depending upon the installed sensor type. Strobe indicators are limited to flash only during
battery backup operations to extend the available operational time.

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1.3.6. Additional Relay Outputs
An additional Four (4) Single Pole, Double Throw (SPDT) 5A relays can be added to SensAlarm Flex.
They are identical in operation to the standard relays in that the PCA includes LED lights for indication of
individual relay activations, but relays can be configured to function independently.
1.4. SensAlarm Flex Components
1.4.1. Sensor Interface Assembly
The sensor interface assembly is intrinsically safe, and contains the
electronics that operate and house Plus Series Sensors and the
optional Test-on-Demand™ cell.
1.4.2. Plus Series Sensor
Plus Series Sensors are available in a variety of sensor technologies for
detecting Toxic, Oxygen, and Combustible gases. The Plus Series Sensor
is discussed in greater detail in Section 1.4.16. The sensor gasket seals
the sensor inside the sensor holder.
1.4.3. Test-on-Demand
The optional Test-on-Demand™ (ToD™) gas generating cell provides
a method for periodic sensor response verification (programmed or manually
activated). The T-O-D gasket seals the generating cell inside the sensor holder.
1.4.4. Sensor Holder
The sensor and ToD™ gas generating cell are housed in the Sensor Holder.
The sensor holder is easily installed and removed via the retaining ring located
on the sensor interface assembly. The sensor holder is black anodized Aluminum,
optional gray PVC, or 316 Stainless-Steel.
1.4.5. Rainshield & Moisture Barrier
The optional Rainshield protects the sensor and ToD cell from liquid intrusion
due to rain, splash-back, or unintentional washdown, and offers an optional
highly recommended calibration port. The Moisture Barrier is an optional
component for a higher level of moisture protection. Target gases penetrate
the Moisture Barrier, where moisture does not. The Moisture Barrier is required
for use with IR sensor methods.
1.4.6. Calibration Plug
The Calibration Plug secures through a friction fit into the sensor shield at the
bottom of the sensor holder, which ensure a leak-tight introduction of calibration
gas standards. If not using the Rainshield with calibration port, the Calibration Plug
is a required accessory.

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1.4.7. Relays
Four (4) Standard Single Pole, Double Throw (SPDT) 5A relays are included in SensAlarm Flex. The
option for an additional four (4) relays is available. The Relay Printed Circuit Assembly (PCA) inside the
Gas Monitor includes LED lights for indication of individual relay activations. Once the front panel is
opened, the relay LED lights and wire termination plugs are easily accessible.

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1.4.8. Modbus
SensFlex includes both Modbus TCP and RTU (RS-485) standard. Both are easily accessible and are
located on the right of the Main PCA. Modbus TCP accepts a standard RJ-45 Ethernet cable. Modbus
RTU can be wired in half duplex (2-wire) or full duplex (4-wire).

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1.4.9. 4 to 20 mA Output
The standard 4 to 20mA outputs are located in the bottom left hand side of the enclosure.
CH-1 represents the Left Sensor Interface, and CH-2 the right. CH-2 only functions when SensAlarm
Flex is configured with the optional second Sensor Interface.

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1.4.10. Battery Backup
The Gas Monitor offers an optional Battery Backup, which will power the unit in the event of a line power
failure. It provides 30 minutes operation in full alarm and 60 minutes minimum when not in alarm. While
line power is available, the Battery Backup remains in a continuous trickle charge. If SensAlarm Flex is
configured with Battery Backup, it is located in the bottom right hand side.

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1.4.11. Horn and Silence Pushbutton
SensAlarm Flex offers a standard 95dB Horn that can be silenced by an externally mounted pushbutton
that conforms to ISA Alarm Sequence 3A.

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1.4.12. Front Panel LED Strobe
The Universal Gas Monitoring Systems includes as a standard feature the “All-In-One” system
requirements of visual alarm / fault notification. Unlike traditionally used stack lights, the front panel
strobe does not take up unnecessary space, and ensures the Gas Monitor maintains the smallest
footprint possible. The Front Panel LED Strobe offers green, red, amber and blue visual notifications.
1.4.13. Stack Light
When 360° alarm notification visibility is required,
SensAlarm Flex offers an optional Stack Light that can be
configured with either one, two, three or four strobes.
The Stack Light will follow the Front Panel LED Strobe
configuration.

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1.4.14. SensAlarm Flex Components (Summary)