Det-Tronics FlexSight LS2000 User manual

2.2 Rev: 3/15 95-8714
Instructions
Line of Sight
Infrared Hydrocarbon Gas Detector
Model LS2000

Table of Contents
APPLICATION ............................ 1
OPERATION OVERVIEW.................... 2
Theory of Operation...................... 2
Detectable Gases........................ 2
Detection Ranges........................ 2
Standard Output......................... 2
Optional Relays ......................... 4
Optional Communication Link .............. 4
History Logs ............................ 4
OPERATION.............................. 5
Internal Magnetic Switch/Calibration Line
Terminal ........................... 5
Module Identication ..................... 5
Factory Reset Command .................. 5
Operating Modes ........................ 6
4-20 mA Current Loop Output .............. 6
Heater Control .......................... 7
Status and Fault Indication.................10
SPECIFICATIONS .........................10
IMPORTANT SAFETY NOTES................14
INSTALLATION............................14
Identication of Vapor(s) to be Detected ......14
System Location Considerations ............14
Module Mounting Recommendations.........16
Replacing an Existing Model OPECL with an
LS2000 .............................18
24 VDC Power Supply Requirements.........18
Wiring Cable Requirements ................18
Power Wiring Size and Maximum Length......18
Optional Relays .........................19
Wiring Procedure ........................19
STARTUP ............................... 22
ALIGNMENT............................. 23
Overview ............................. 23
Equipment Required .................... 23
Alignment Procedure .................... 23
Aperture Kit for Short Range Applications .... 25
Recommendations for using the HART Field
Communicator ....................... 26
Gain Level Check....................... 26
Transmitter Lamp Voltage................. 27
CALIBRATION ........................... 27
Calibration Overview .................... 27
Zero Calibration ........................ 27
Important Calibration Notes ............... 27
Calibration Initiation ..................... 28
Calibration Sequence.................... 28
MAINTENANCE .......................... 29
Routine Inspection ...................... 29
Optics Cleaning ........................ 29
Functional Checking..................... 29
Protective Caps and Covers ............... 29
TROUBLESHOOTING ..................... 30
REPLACING LS2000 TRANSMITTER/
RECEIVER ELECTRONICS MODULE ........ 31
Module Replacement Procedure ........... 31
DEVICE REPAIR AND RETURN ............. 32
ORDERING INFORMATION ................ 33
Alignment Equipment.................... 33
Accessories ........................... 33
Spare Parts ........................... 33
Assistance ............................ 33
APPENDIX A - FM APPROVAL DESCRIPTION . 35
APPENDIX B - CSA CERTIFICATION
DESCRIPTION........................... 37
APPENDIX C - OTHER APPROVALS ......... 39
APPENDIX D - HART COMMUNICATION ...... 40

IMPORTANT
Be sure to read and understand the
entire instruction manual before installing
or operating the gas detection system.
This product is intended to provide early
warning of the presence of a ammable
or explosive gas mixture. Proper device
installation, operation, and maintenance
is required to ensure safe and effective
operation.
application
The Model LS2000 is a line of sight infrared
gas detection system that provides continuous
monitoring of combustible hydrocarbon gas
concentrations in the range of 0 to 5 LFL-meters,
over a distance of 5 to 120 meters. Standard
system outputs include an electrically isolated/
non-isolated 4-20 mA dc current output with
the ability to go below 4 mA to indicate fault
conditions, and also HART and RS-485
MODBUS communication. Alarm and fault
relays are available as an option.
The system consists of two stainless steel
modules — a transmitter and a receiver, along
with mounting and alignment bracket. The
receiver provides the measurement signal
outputs, and is furnished with onboard “status
indication” LEDs and an internal magnetic
calibration switch. The transmitter houses
a high quality xenon flash lamp and “status
indication” LEDs. Both modules are powered
from an external 24 volt DC supply and are
equipped with microprocessor controlled
heated optics to increase resistance to moisture
and ice. Both modules must be installed at
approximately the same elevation and must be
aligned to point directly at one another. No
direct electrical interconnection between the two
modules is required.
The LS2000 is certified explosion-proof for use
in Class I, Division 1 and Division 2 hazardous
areas, and holds third party performance
certification for methane gas detection.
Propane and butane detection are also available
(Det-Tronics verified). It can be used as
a stand-alone detector, or as part of a larger
facility protection system using other Det-Tronics
equipment.
2.2 ©Detector Electronics Corporation 2015 Rev. 3/15 95-8714
INSTRUCTIONS
Line of Sight
Infrared Hydrocarbon Gas Detector
Model LS2000

2.2 95-87142
opERation ovERviEw
THEORY OF OPERATION
The LS2000 transmitter module uses a
Xenon flash lamp to produce a collimated IR
light source. This light source illuminates the
path between transmitter and receiver. The
transmitter uses a filter to block visible light
emissions and is eye safe.
As flammable hydrocarbon gases intersect the
light beam between the two modules, certain
IR wavelengths are absorbed by the gas, while
other IR wavelengths are not. The amount of IR
absorption is determined by the concentration of
the hydrocarbon gas. A pair of optical detectors
and associated electronics located in the
receiver module measure the absorption. The
change in intensity of the absorbed light (active
signal) is measured relative to the intensity of
light at a non-absorbed wavelength (reference
signal). The microprocessor computes the
gas concentration and converts the value
into a 4-20 mA current output signal, which
is then communicated to external control and
annunciation systems.
The gas concentration is indicated by a 4-20 mA
signal, which corresponds to 0-5 LFL-meters.
To better understand the concept of LFL-meters,
refer to Figure 1, which shows how three gas
clouds of different size and concentration would
produce the same output of 1 LFL-meter by the
line of sight gas detection system. To convert
a given LFL-m value to ppm-m for methane,
propane or butane gas, refer to Table 1.
DETECTABLE GASES
The LS2000 is capable of detecting most
hydrocarbon gases and vapors including
methane, propane, and butane. Gas type
and other operational parameters are selected
via HART or MODBUS communication. The
LS2000 is factory calibrated to methane,
propane, and butane, and comes from the
factory set for methane.
DETECTION RANGES
The LS2000 is offered in two detection ranges in
order to meet customer needs, as listed below:
Short Range 5-60 meters
Long Range 30-120 meters
For installations with short separation distances
(5-15 meters for the short range model and
30-40 meters for the long range model), the
range reduction aperture kit (supplied) is
required. Refer to “Aperture Kit for Short Range
Applications” section in this manual for details.
The correct range for the LS2000 must be
chosen to meet specific application needs.
The detection range of the LS2000 pair is
determined by the Receiver. Receiver units
can be converted from long to short or short
to long range in the field by replacing the front
electronics module. A single transmitter model
is used for both detection range options.
STANDARD OUTPUT
The LS2000 receiver module provides an analog
4-20 mA signal output. HART and RS-485
MODBUS serial communication are available
at either module. The 4-20 mA current loop
corresponding to 0 to 5 LFL-meters is provided
for connection to analog input devices such as
gas controllers, logic controllers, or distributed
control systems (DCS). To convert the mA
reading to LFL-meters, use the following formula:
mA Reading –4
X 5 = LFL-Meters
16
1M @ 100% LFL = 1 LFL-M
2M @ 50% LFL = 1 LFL-M
10M @ 10% LFL = 1 LFL-M
LS2000 OUTPUT EQUALS 1 LFL-M IN ALL THREE SCENARIOS
A2665
Figure 1—Detector Response to Three Gas Clouds
of Different Size and Concentration

395-87142.2
Gas Path Length
(m)
Cloud
Concentration
(LFL)
Cloud
Concentration
(v/v, by volume)
Cloud
Concentration
(ppm)
LFL-m ppm-m
Methane 1 100% 5.0% 50000 1 50000
Methane 2 100% 5.0% 50000 2 100000
Methane 3 100% 5.0% 50000 3 150000
Methane 4 100% 5.0% 50000 4 200000
Methane 5 100% 5.0% 50000 5 250000
Propane 1 100% 2.2% 22000 1 22000
Propane 2 100% 2.2% 22000 2 44000
Propane 3 100% 2.2% 22000 3 66000
Propane 4 100% 2.2% 22000 4 88000
Propane 5 100% 2.2% 22000 5 110000
Butane 1 100% 1.9% 19000 1 19000
Butane 2 100% 1.9% 19000 2 38000
Butane 3 100% 1.9% 19000 3 57000
Butane 4 100% 1.9% 19000 4 76000
Butane 5 100% 1.9% 19000 5 95000
Table 1—LFL-m to PPM-m Conversion

2.2 95-87144
OPTIONAL RELAYS
The
LS2000 can be furnished with factory
installed relays — two programmable alarm
relay outputs and one fault relay output. All
relays are sealed and provide form C (NO/
NC) contacts. The high and low alarm relays
are programmable, and can be set for latching
/ non-latching operation, and a normally
energized / de-energized coil (see Table 3).
The low alarm cannot be set above the high
alarm threshold. Alarm configuration can be
done with the HART or MODBUS interface.
The onboard multi-color LEDs indicate a LOW
alarm condition via a flashing red color, and a
HIGH alarm condition via a steady red color.
Latched alarms can be reset using the internal
magnetic switch, an external switch connected
to the calibration line terminal, a HART Field
Communicator, or MODBUS communication.
A short-duration magnetic switch activation of
1 second will reset latched alarms. Holding
the magnetic switch closed for a 3 second
duration will start the calibration sequence.
When the optional relays are ordered, the
LS2000 receiver is certified for Ex d operation.
OPTIONAL COMMUNICATION LINK
By connecting the transmitter and receiver
via a three-wire shielded cable, an optional
“communication link” can be created between
the two devices.
The communication link offers the following
advantages:
1. Single point system diagnostics – The link
offers the ability to view device variables
of the receiver while connected to the
transmitter, or vice versa (using a HART
handheld or MODBUS device). These
variables include signal strength, status, and
configuration parameters such as alarm set
points, heater settings, gas type, etc.
2. Dynamic lamp power – The link enables
the system to optimize lamp power per the
application. This optimization only happens
during the zero calibration process.
3. Synchronized LEDs on each device can
signal a common system status condition.
Without the link, the transmitter is unable to
signal alarm status.
4. Transmitter variables can be configured via
connection to the receiver. Configurable
transmitter variables include lamp power and
heater settings.
NOTE
Alarm setpoints in the receiver cannot be
changed from the transmitter.
5. The communication link provides the ability to
initiate Calibration from either the transmitter
or receiver.
For retrofit applications where an inter-
connecting wire is not available or possible, the
system can operate without the link. If the link
is not connected, the system will not indicate a
“link fault.”
A “link fault” feature can be enabled (using a
HART handheld or MODBUS device), which
will indicate a fault if the link is broken. The “link
fault” can only be detected and annunciated by
the receiver.
NOTE
The default setting for the”link fault”
feature is Disabled.
NOTE
All third-party performance and
hazardous location approvals apply
with and without the communication link
connected.
HISTORY LOGS
Non-volatile memory is provided in the receiver
to save a record of the 100 most recent
calibrations and 1000 most recent alarm/fault
events. Operating temperature and voltage
of the receiver are also recorded with each
event log. A real time clock is provided for time
stamping events. This information is accessible
using HART or MODBUS communication.

595-87142.2
opERation
INTERNAL MAGNETIC SWITCH /
CALIBRATION LINE TERMINAL
An internal magnetic switch is provided for
resetting latched alarms and initiating field zero
calibration. See Figure 2 for switch location.
The same functions can be accomplished
remotely by installing a switch (momentary
closure) between the CAL and 0V COM
terminals on the LS2000 receiver. Momentary
switch activation will reset alarms, while holding
the switch closed for 3 seconds or longer (not
to exceed 30 seconds) will start the calibration
sequence. The LEDs will begin flashing green
(5 Hz) when the reset criteria have been met and
will change to flashing yellow (5 Hz) when the
calibration period has been met (>3 seconds,
<30 seconds). The device will reset if the switch
is released during a flashing green LED and will
enter calibration if the switch is released during a
flashing yellow LED.
MODULE IDENTIFICATION
See Figure 3 for identification of the transmitter
and receiver modules. The functional and
electrical characteristic differences of the two
devices are described in Table 2.
FACTORY RESET COMMAND
The LS2000 provides a factory reset command
that sets all user configurable parameters
back to their default settings. This command
can be accessed via HART or MODBUS
communication.
PLACE CALIBRATION MAGNET HERE
TO ACTIVATE INTERNAL REED SWITCH
A2648
Figure 2—Location of Internal Magnetic Switch
on Receiver Module
Table 2—Functional and Electrical Comparison of Transmitter and Receiver
Characteristic Transmitter Receiver
Functional Description Contains a xenon flash lamp,
and generates optical energy to
enable hydrocarbon detection.
Contains opto-electronics, signal processing,
output drivers, and diagnostic electronics.
Electrical Connections Connections for power, HART,
RS-485, Communication Link.
Connections for power, 4-20 mA, HART,
RS-485, relay contacts (optional),
Communication Link, and calibration/reset.
Onboard LED Indicators Indicates device status.
Green indicates normal
operation.
Yellow indicates fault condition.
When the Communication Link
is used, the transmitter LED
operation matches receiver
LED operation, including alarm
status.
Indicates normal, alarm, fault, and calibration
status.
Green indicates normal operation. Blinking red
indicates low gas alarm condition.
Steady red indicates high gas alarm condition.
Yellow indicates system fault. See Tables 4 and
5 for details.
LED operation for fault status is non-latching.
LED operation for gas alarms is configurable
for latching/non-latching.
Magnetic Calibration
Switch (See Figure 2 for
switch location.)
NA Momentary activation provides reset function
for latched alarm outputs. Activation for longer
than 3 seconds will initiate zero calibration.
Adjustable Settings Programmable IR signal intensity
and heater operation. HART
or MODBUS communication is
required to change the factory
default settings.
Factory calibrated for methane, propane, and
butane, 0-5 LFL-meters full scale. Default gas
depends on model. See Table 3 for receiver
factory default settings. HART or MODBUS
communication is required to change the
factory default settings.

2.2 95-87146
OPERATING MODES
The LS2000 has three operating modes: warm-
up, normal (measuring / monitoring), and
calibrate.
Warm-up
Warm-up mode is entered upon application
of 24 Vdc operating power. During warm-up,
the 0-20 mA current loop output will indicate
warm-up, the indicating LED is yellow, and
the alarm outputs are disabled. The warm-up
time typically lasts from 15 to 150 seconds,
depending upon alignment accuracy.
Normal
After warm-up mode is completed, the device
automatically enters the Normal mode, and all
analog and alarm outputs are enabled. The
LS2000 modules must be properly aligned
before normal operation is attained. See
INSTALLATION section for details.
Calibrate
After alignment is completed, zero calibration
is required. Span calibration of the LS2000
is performed at the factory; however, the user
has the option to verify proper calibration if
necessary. It is recommended that the zero
calibration procedure be performed annually.
Refer to the “Calibration” section in this manual
for details.
4-20 MA CURRENT LOOP OUTPUT
The LS2000 provides a linear current loop
output that is proportional to the detected gas
level. Fault and calibration status are also
indicated by this output.
The full-scale output corresponding to 5
LFL-meters is 20 mA. HART and MODBUS
interfaces also have the ability to calibrate (trim)
the 4 mA and 20 mA levels.
The LS2000 is equipped with output monitoring
circuitry for the current loop and will indicate
a fault when the output mA level does not
match the output set point of the device. This
monitoring (disabled by default) will indicate
a fault if the current loop is not terminated
correctly. The loop monitoring feature can be
enabled via HART or MODBUS communication.
Figure 3— Identication of Transmitter and Receiver Modules
TRANSMITTER RECEIVER
A2647
Table 3—Factory Default Settings
Default Congurable Options
Gas Type Methane Methane, Propane,
Butane
Low Alarm
Threshold
( L F L- M )
10.5 to 4.5
(10% to 90%)
High Alarm
Threshold
( L F L- M )
30.5 to 4.5
(10% to 90%)
High & Low
Alarm Relays
( Optional )
Non-Latching,
De-Energized
Latching/Non-Latching,
Energized/
De-Energized
Beam Block
Delay 60 Seconds 60–3600 Seconds
Fault Mode LS2000 LS2000, Advanced,
User Defined
Heater
Mode* Smart Mode Smart Mode, Always On, Always Off
*See "Heater Control" section for details.
NOTE:
The system must be configured for less than 60% of the
full scale measuring range, with consideration to the
accepted gas cloud size and concentration.

795-87142.2
HEATER CONTROL
The LS2000 optics in both transmitter and
receiver are heated to provide moisture and ice
resistance. These heaters are microprocessor
controlled and can be configured to operate in
the following modes:
– Always On
– Always Off
– Smart Mode (default)
1) Heaters maintain a user programmable
temperature set point (default = 50°C).
2) Heaters increase to full power when signal
strength is degraded due to moisture or
condensation on the window, or any
obscuration faults are active.
3) Heaters shut off when the input voltage
drops below a user defined level (default =
18.5 Vdc).
4) Heater power usage can be limited from
0-100% (default uses up to 100% power
if needed). See Specifications section for
power consumption details.
Table 6 indicates the typical window glass
temperature rise for various heater setting and
ambient temperature combinations.
NOTE
Higher heater settings reduce or eliminate
moisture buildup on the window, thereby
providing optimum detector performance.
Table 6—Typical LS2000 Window Temperature Rise (Degrees C)
for Various Heater Settings and Ambient Temperatures
LS2000 Window
Temperature Rise (C)
AMBIENT TEMPERATURE
-55°C -40°C 0°C 25°C
30%
Heater
Setting
Receiver 5.1 5.3 4.5 3.0
Transmitter 4.2 4.1 4.2 3.0
50%
Heater
Setting
Receiver 7.2 6.8 7.0 5.0
Transmitter 5.3 5.2 5.3 3.6
70%
Heater
Setting
Receiver 9.8 9.1 7.5 7.1
Transmitter 7.8 6.6 5.1 3.8
100%
Heater
Setting
Receiver 15.8 14.9 8.6 7.3
Transmitter 13.3 10.6 5.9 4.5
Table 4—LS2000 Receiver Status Conditions
Status
4-20mA Output Relays
LED
LS2000
Default Advanced User Dened Fault Relay Alarm Relay
Warm up 1.0 1.0 Detection
Disabled De-energized Disabled Yellow - Solid
Normal 4.0 to 20.5 4.0 to 20.5 4.0 to 20.5 Energized Enabled
Green - Solid = Normal
Red - Flashing = Low Alarm
Red - Solid = High Alarm
Zero
Calibration 1.0 2.2 Configuration Energized Disabled Yellow - Flashing @ 5 Hz
Note: When the Communication Link is used, the transmitter LED operation matches receiver LED operation,
including alarm status.

2.2 95-87148
Status
4-20mA Output Relays
LED
Default Advanced User
Dened Fault Relay Alarm Relay
4-20 Fault
(Open Loop) 0.0 0.0 0.0 De-energized Enabled Yellow - Solid for 10 seconds, followed by 1 Pulse
RAM Fault 1.0 1.2 Detection
Disabled De-energized Disabled Yellow - Solid
Data Flash Fault 1.0 1.2 Detection
Disabled De-energized Disabled Yellow - Solid
Flash CRC Fault 1.0 1.2 Detection
Disabled De-energized Disabled Yellow - Solid
AFE Fault 1.0 1.2 Detection
Disabled De-energized Disabled Yellow - Solid
Internal Voltage
Fault 1.0 1.2 Detection Disabled De-energized Disabled Yellow - Solid
Active Signal
Saturated 1.0 1.2 Detection Disabled De-energized Disabled Yellow - Solid
Ref. Signal
Saturated 1.0 1.2 Detection Disabled De-energized Disabled Yellow - Solid
Low Voltage 1.0 1.4 Advisory De-energized Enabled Yellow - Solid for 10 seconds,
followed by 2 Pulses
High Voltage 1.0 2.0 Advisory De-energized Enabled Yellow - Solid for 10 seconds,
followed by 8 Pulses
Heater Fault 1.0 1.6 Advisory De-energized Enabled Yellow - Solid for 10 seconds,
followed by 3 Pulses
Broken Link 1.0 1.8 Advisory De-energized Enabled Yellow - Solid for 10 seconds,
followed by 4 Pulses
Failed Zero
Calibration 1.0 2.4 Advisory De-energized Enabled Yellow - Solid for 10 seconds, followed by 5 Pulses
Calibrate
Active at Startup 1.0 2.6 Advisory De-energized Enabled Yellow - Solid for 10 seconds, followed by 6 Pulses
Beam Block 2.0 2.8 Detection
Disabled De-energized Disabled Yellow - Solid for 10 seconds, followed by 7 Pulses
Low Signal 3.0 3.2 Advisory De-energized Enabled Yellow - Solid for 10 seconds,
followed by 9 Pulses
Negative Drift
–9% of Scale 1.0 3.6 Advisory De-energized Enabled Yellow - Solid for 10 seconds, followed by 10 Pulses
Over Range 20.5 20.5 20.5 Energized Enabled Red - Solid
Table 5—LS2000 Receiver Fault Conditions