Critical Environment Technologies LPT Series User manual

Operation Manual
www.critical-environment.com
LPTLow Power Transmitter
Rev. E | 2021.03

2 © 2021 All rights reserved. Data subject to change without notice.
LPT - Operation Manual Rev. E | 2021.03
TABLE OF CONTENTS
1 POLICIES.......................................................................................................... 5
1.1 Important Note................................................................................................5
1.2Warranty Policy................................................................................................6
1.3 Service Policy...................................................................................................6
1.4 Copyrights........................................................................................................8
1.5 Disclaimer........................................................................................................8
1.6 Revisions..........................................................................................................8
2 INTRODUCTION .............................................................................................9
2.1 General Description..........................................................................................9
2.2 Key Features...................................................................................................10
3 INSTRUMENT SPECIFICATIONS .................................................................11
3.1Technical Specications..................................................................................11
3.2 Enclosure Dimensions....................................................................................13
4 SENSOR SPECIFICATIONS...........................................................................14
4.1 List of Available Internal Sensors....................................................................14
4.2 Calibration Extending Firmware (CEF) and Sensor Aging................................14
5 FEATURES & FUNCTIONS............................................................................15
5.1 Exterior Enclosure ..........................................................................................15
5.2 Interior System Layout...................................................................................16
6 INSTALLATION..............................................................................................17
6.1 Special Considerations for DierentType of Sensors.......................................17
6.2 General Safety Warnings................................................................................18
6.3 Protection Against Electrical Risks..................................................................18
6.4 Protection Against Mechanical Risks..............................................................19

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6.5 Mounting theTransmitter..............................................................................19
6.5.1Wet Environment Considerations ....................................................................20
6.5.2 EMI and RF Interference Considerations..........................................................20
6.5.3 Sensor Mounting Height (Sensor Dependent).................................................21
6.6 Enclosure Mounting Components ..................................................................22
6.6.1 Enclosure Base ................................................................................................22
6.6.2 Enclosure Bottom............................................................................................23
6.7Wiring Connections........................................................................................23
6.7.1 Power & Output Connection............................................................................24
6.7.2Wire Gauge vs Run Length...............................................................................25
6.7.3 Open Loop.......................................................................................................26
7 OPERATION...................................................................................................26
7.1 System Operation...........................................................................................26
7.2 Fault Detection...............................................................................................26
7.3Test Functions ................................................................................................27
7.4 Jumpers.........................................................................................................27
8 CALIBRATION................................................................................................30
8.1 Calibration Specications...............................................................................30
8.1.1 Gas..................................................................................................................30
8.1.2 Regulators & Flow...........................................................................................30
8.1.3 Adapters..........................................................................................................30
8.1.4 Calibration Frequency .....................................................................................31
8.1.5 Gas Testing Frequency (Bump Testing)............................................................31
8.1.6 Sticky Gases.....................................................................................................31
8.2 Calibrating the Internal Sensor ......................................................................32
8.3 Calibrating an Oxygen Sensor ........................................................................36

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9 ACCESSORIES ...............................................................................................39
9.1 Splash Guard..................................................................................................39
9.2 Calibration Adapter Clip“Cal Clip”...................................................................40
9.3 Metal Protective Guard ..................................................................................40
9.4 Calibration Kit................................................................................................41
10 MAINTENANCE ..........................................................................................42
11 TROUBLE SHOOTING ................................................................................42

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1 POLICIES
1.1 Important Note
Read and understand this manual prior to using this instrument. Carefully read the warranty policy,
service policy, notices, disclaimers and revisions on the following pages.
This product must be installed by a qualied electrician or trained technician and according to
instructions indicated in this manual.This instrument should be inspected and calibrated regularly
by a qualied and trained technician. For more information, refer to sections 10 Maintenance and 8
Calibration of this manual.
This instrument has not been designed to be intrinsically safe. For your safety, do not use it in
classied hazardous areas (explosion-rated environments).
INSTRUMENT SERIAL NUMBER:
______________________________________________________
PURCHASE DATE:
______________________________________________________
PURCHASED FROM:
______________________________________________________

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1.2 Warranty Policy
Critical Environment Technologies Canada Inc. warrants the products we manufacture (excluding
sensors, battery packs, batteries, pumps, and lters) to be free from defects in materials and
workmanship for a period of two years from the date of purchase from our facility. As a reminder,
sensors are consumable items and once they leave our factory, we cannot reuse or resell them.
As such, all sensor sales are nal. Should the sensor itself be faulty, there is a one-year pro-rated
warranty that would apply from the date of purchase from our facility.
The warranty status may be aected if the instrument has not been used and maintained as per
the instructions in the manual or has been abused, damaged, or modied in any way. The product
is only to be used for the purposes stated in the manual. Critical EnvironmentTechnologies is not
liable for auxiliary interfaced equipment or consequential damage.
All returned goods must be pre-authorized by obtaining a Returned Merchandise Authorization
(RMA) number. All goods must be shipped to Critical EnvironmentTechnologies freight prepaid.
Contact the manufacturer for an RMA number and procedures required for product transport.
Due to ongoing research, development, and product testing, the manufacturer reserves the right to
change specications without notice.The information contained herein is based on data considered
accurate. However, no warranty is expressed or implied regarding the accuracy of this data.
1.3 Service Policy
CETCI maintains an instrument service facility at the factory. Some CETCI distributors / agents may
also have repair facilities; however, CETCI assumes no liability for service performed by anyone
other than CETCI personnel.
Repairs are warranted for 90 days after date of shipment (sensors have individual warranties).
Should your instrument require non-warranty repair, you may contact the distributor from whom it

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was purchased or you may contact CETCI directly.
Prior to shipping equipment to CETCI, contact our oce for an RMA #. All returned goods must be
accompanied with an RMA number.
If CETCI is to do the repair work, you may send the instrument, prepaid, to:
Attention: Service Department
Critical Environment Technologies Canada Inc.
Unit 145, 7391 Vantage Way
Delta, BC, V4G 1M3
You must include your Returned Merchandise Authorization (RMA) number, address, telephone
number, contact name, shipping / billing information, and a description of the defect as you
perceive it. You will be contacted with a cost estimate for expected repairs, prior to the performance
of any service work. Pack the equipment well (in its original packing if possible), as we cannot
be held responsible for any damage incurred during shipping to our facility. All incurred shipping
charges, duties and taxes are your responsibility.
For liability reasons, CETCI has a policy of performing all needed repairs to restore the instrument to
full operating condition.
1.4 Copyrights
This manual is subject to copyright protection; all rights are reserved. Under international and
domestic copyright laws, this manual may not be copied or translated, in whole or in part, in any
manner or format, without the written permission of CETCI.
1.5 Disclaimer
Under no circumstances will CETCI be liable for any claims, losses or damages resulting from or
arising out of the repair or modication of this equipment by a party other than CETCI service

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LPT - Operation Manual Rev. E | 2021.03
technicians, or by operation or use of the equipment other than in accordance with the printed
instructions contained within this manual or if the equipment has been improperly maintained or
subjected to neglect or accident. Any of the forgoing will void the warranty.
Under most local electrical codes, low voltage wires cannot be run within the same conduit as line
voltage wires. It is CETCI policy that all wiring of our products meet this requirement.
It is CETCI policy that all wiring be within properly grounded (earth or safety) conduit.
1.6 Revisions
This manual was written and published by CETCI.The manufacturer makes no warranty or
representation, expressed or implied including any warranty of merchantability or tness for
purpose, with respect to this manual.
All information contained in this manual is believed to be true and accurate at the time of printing.
However, as part of its continuing eorts to improve its products and their documentation, the
manufacturer reserves the right to make changes at any time without notice. Revised copies of this
manual can be obtained by contacting CETCI or visiting www.critical-environment.com.
Should you detect any error or omission in this manual, please contact CETCI at the following
address:
Critical Environment Technologies Canada Inc.
Unit 145, 7391VantageWay, Delta, BC,V4G 1M3, Canada
Toll Free: +1.877.940.8741
Telephone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.critical-environment.com

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In no event will CETCI, its ocers or employees be liable for any direct, special, incidental or
consequential damages resulting from any defect in any manual, even if advised of the possibility
of such damages.
2 INTRODUCTION
2.1 General Description
Thank you for purchasing our single sensor, analog LPT Low PowerTransmitter.
The LPT is a rugged, easy-to-use analog gas detection transmitter for use as part of a xed system
with a Controller in non-hazardous (non-explosion rated) environments. Ideal applications include
car parks, vehicle repair, aquatic centers, ice rinks and oxygen depletion environments.
It features a two-wire loop power, three-wireVDC or four-wire VAC power, 4 - 20 mA linear output
signal, thermal resetting fuses, temperature compensation, and visual LED indication for power and
fault conditions (refer to Section 3.1 Technical Specications), all in a RoHS compliant package.
It comes standard with a water / dust tight, corrosion resistant ABS / polycarbonate enclosure with
a hinged, secured door. With the optional splash guard installed, the enclosure is IP54 rated and
ideal for use in water spray or wash down applications.
The LPT operates by diusion. The sensors used in this device are accurate enough to measure to
Occupational Health & Safety (OHS) hazardous levels for toxic gases.
If after reading through the manual, you have any questions, please do not hesitate to contact our
Technical Service Department for technical support.

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2.2 Key Features
• Single sensor
• 2-wire loop, 3-wire VDC or 4-wire VAC power
• Linear 4 - 20 mA output signal
• Standard water / dust tight, corrosion resistant enclosure (drip proof)
• Optional splash guard to protec sensor in wash down applications; IP54 rated when factory
installed
• RoHS compliant circuit boards
• Easy maintenance, economical
• Includes sensor CEF (calibration extending rmware) for parking garage applications
• Auto resetting fuses
3 INSTRUMENT SPECIFICATIONS
3.1 Technical Specications
MECHANICAL
Enclosure ABS / Polycarbonate, copper coated interior to reduce RF
interferance, IP54 rated with splash guard installed
Weight 400 g (14 oz)
Size 127 mm x 127 mm x 48.5 mm (5.0”x 5.0”x 1.91”)

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ELECTRICAL
Power Requirement
2-wire mode
3-wire mode
4-wire mode
16 - 30VDC, 1 W, Class 2
16 - 30VDC, 1 W, Class 2
12 - 27VAC, 50 - 60 Hz, 1 VA, Class 2
Use Class 2 transformer. See Section 6.7 Wiring Connections.
Current Draw Maximum 25 mA
Outputs
Linear 4 - 20 mA
Maximum 216 Ω load (wiring plus termination resistor) at 16 VDC
Maximum 316 Ω load (wiring plus termination resistor) at 12 VAC
Wiring
VDC two or three conductor shielded 18 awg (or larger) stranded
within conduit
VAC four conductor shielded 18 awg (or larger) stranded within
conduit (refer to Section 6.7.2 Wire Gauge vs. Run Length)
Fuse Automatic resetting thermal
Indicator
Solid Green: Power ON
Flashing Green (50% duty cycle):Warm up
Flashing Green (short OFF, long ON): Fault mode
LED OFF: No Power or 4-20 mA“Open Loop” (unit won’t operate)
ENVIRONMENTAL (sensor dependant)
OperatingTemperature -20°C to 40°C (-4°F to 104°F)

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Operating Humidity 15 - 90% RH non-condensing
CERTIFICATION
Model: LPT-XXX
S/N: LPT1601E00374
Rating: 16-30VDC, 1W, Class 2
12-27VAC, 50-60 Hz 1VA, Class 2
CERTIFIED FOR ELECTRIC SHOCK & ELECTRICAL FIRE HAZARD ONLY. LA CERTIFICATION ACNOR
COUVRE UNIQUEMENT LES RISQUES DE CHOC ELECTRIQUE ET D’INCENDIE D’ORIGINE ELECTRIQUE.
Conforms to: CSA-C22.2 No. 205-M1983 (R2009), UL508 (Edition 17):2007
Conforms to: EMC Directive 2004/108/EC, EN 50270:2006,Type 1, EN61010
Conforms to: FCC. This device complies with Part 15 of the FCC Rules. Operation is subject to the
following two conditions: (1)This device may not cause harmful interference, and (2) This device
must accept any interference that may cause undesired operation.

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3.2 Enclosure Dimensions
1.91”(48.5 mm)
2.24”(57 mm) with splash
guard (not shown)
5.0”(127 mm)
5.0”(127 mm)

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4 SENSOR SPECIFICATIONS
4.1 List of Available Internal Sensors
Internal Electrochemical
Sensors Part Number Range Lifespan
Ammonia (NH3) LPT-NH3 0 - 500 ppm ~2 years
Carbon Monoxide (CO) LPT-TCO 0 - 200 ppm ~3 years
Chlorine (Cl2) LPT-CL2 0 - 5.0 ppm ~3 years
Hydrogen Sulphide (H2S) LPT-H2S 0 - 50 ppm ~2 years
Nitrogen Dioxide (NO2) LPT-END 0 - 10 ppm ~3 years
Oxygen (O2) LPT-O2 0 - 25% vol ~3 years
Sulphur Dioxide (SO3) LPT-SO2 0 - 20 ppm ~2 years
4.2 Calibration Extending Firmware (CEF) and Sensor
Aging for CO and NO2Sensors
LPT systems with integral CO or NO2electrochemical sensors have been programmed with our CEF
(Calibration Extending Firmware).This rmware takes into consideration the aging of the sensors
so that less frequent calibrations are acceptable in less-critical applications such as parking garages.
The system tracks the age of the sensor and automatically compensates for the reduced output of
the sensor as it ages.

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5 FEATURES & FUNCTIONS
5.1 Exterior Enclosure
NUMBER FEATURE FUNCTION
ŒDoor Hinge Secures door
•LED Indicator Indicates Power & Fail
ŽDoor Screw Secures door
•Sensor Opening To monitor diused air and gas
•Padlock Opening For padlock
Œ
Œ
•
•
Ž
•

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5.2 Interior System Layout
NUMBER FEATURE FUNCTION
ŒJumpers For calibrations & test functions
•Test Points: TP-1 & TP-2 For measuring voltage output
ŽWiringTerminal Pluggable wiring terminal
•Internal LED Calibration status indicator
Œ
•
•
Ž

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6 INSTALLATION
The sensor in the LPT goes through a burn in period at our factory prior to shipiping so it is ready
for operation upon arrival. If you install the LPT when it arrives, most sensors will not require a
long warm up period (about 5 minutes for Ammonia and Nitrogen dioxide, 2 minutes for the other
gases, except Oxygen which is a minimum of 2 hours). If the device is not installed within two
weeks of delivery, the sensor may require a longer warm up time to stabilize (approximately 48
hours) and provide accurate readings.
NOTE: CETCI suggests that upon power-up, all sensors be left to warm up for 24 hours
prior to considering the gas readings to be accurate.
NOTE: All sensors are calibrated in the factory and do not require calibration at the time
of a routine installation.
NOTE: Temperature aects calibration. It is important to ensure the gas is at the appropriate
temperature during calibration. If the sensor is being used in an extreme temperature range,
calibration should be done in that same temperature range.
6.1 Special Considerations for Dierent Types of
Sensors
After installing an LPT with an Oxygen sensor, leave it to warm up for at least 2 hours before looking
at the readings. If after at least 2 hours, the gas reading is not 20.9%, you should do a respan.
During calibration, when owing span gas on an Ammonia sensor, if the reading climbs higher than
the calibration point after applying gas for 3 minutes, use that reading as the calibration point. It
should be around 300 ppm.

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A bump test will help you determine if a sensor requires calibration. If the sensor still does not
respond as it should after a successful calibration, it probably requires replacing.
6.2 General Safety Warnings
The LPT is intended for indoor use, permanently mounted at a height that is appropriate for the
type of gas being monitored. See Section 6.5 Sensor Mounting Heights.The LPT should be protected
from extreme weather conditions.
The LPT requires no assembly and virtually no maintenance other than regular calibration of the
integral and/or remote sensors and ensuring that excess water or dust is not somehow entering
the enclosure and physically damaging the circuit board or internal components.There are no
serviceable elements other than the calibration instructions outlined in this manual.There are no
replaceable components except the sensors.
6.3 Protection Against Electrical Risks
Disconnect all power before servicing.There may be multiple power sources. Power supply must
have a building installed circuit breaker / switch that is suitably located and easy to access when
servicing is required and should be labelled as LPT supply (disconnecting power to the LPT).
Appropriate markings should be visible at the circuit breaker / switch that is supplying power to
the LPT.
This device may interfer with pacemakers. Modern pacemakers have built-in features to protect
them from most types of interference produced by other electrical devices you might encounter in
your daily routine. If you a have a pacemaker, follow your healthcare provider’s instructions about
being around this type of equipment.

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6.4 Protection Against Mechanical Risks
The door of the ABS / polycarbonate enclosure can be removed if absolutely necessary to facilitate
installation of the base but it is not recommended on this version. Extreme care and caution
must be exercised when removing the door to avoid damaging the hinges. The door
should only be removed when absolutely required.
Simply grasp the door with one hand, being careful not to make contact with any of the internal
components (circuit board), grasp the base with your other hand.Tug on the base and pull straight
apart. DO NOT TWIST. The section of the hinges located on the base should“snap”apart from the
part of the hinges located on the door.
After installation, simply locate the lid hinges over the installed base hinges and pull toward you.
The hinges should easily“snap”back into place.
The ABS / Polycarbonate enclosure has one screw securing the door to the base for electrical
safety and provides an opening to allow the user to apply a padlock or tie wrap if they desire the
transmitter to be locked. See photo reference on preceding pages.
Be aware that the hinged door could potentially pinch ngers and the sharp edges and/or jumper
pins on the board could potentially prick or cut ngers if not handled carefully.
6.5 Mounting the Transmitter
The LPT should be mounted on a at vertical surface using the four 4.4 mm (0.175”) diameter
mounting holes provided to maintain water tight status. Care should be taken to ensure that the
face of the LPT is not obstructed in order to maximize the sensor’s exposure to the environment
being monitored.
Two 12.7 mm (½ in) conduit entry points are provided in the enclosure. Both are located in the

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LPT - Operation Manual Rev. E | 2021.03
enclosure base. One in the rear of the base and one on the bottom edge of the base. See Section 5.7
Enclosure Mounting Components.
The clearance from the PCA to the base enclosure is 12.7 mm (½ in). Do not use a conduit
connector that has more than 12.7 mm (½ in) of thread length.
NOTE: When mounting the enclosure, allow enough room to allow the end user to open the door
fully to access the internal adjustments.
6.5.1 Wet Environment Considerations
If LPT is to be installed in a potential hose down application or any application whereby liquid could
be directed towards the sensor opening, the LPT (depending on gas sensor type) should be ordered
with a factory installed splash guard (Option -S) or a separate metal guard with a factory installed
splash cover (p/n: SCS-8000-WSG). Standard gas sensors like CO, NO2 and O2can be protected with
the factory installed splash guard. Sticky gas sensors like Cl2and O3do not work with a splash
guard, but can be protected by a metal guard with a splash cover.
If used in a wet or wash down application, the conduit hub entering the LPT enclosure
must be a liquid tight type.
Any water or physical damage to the transmitter that occurs from the installer drilling their own
installation holes will not be covered under warranty.
6.5.2 EMI and RF Interference Considerations
All electronic devices are susceptible to EMI (Electromagnetic Interference) and RFI (Radio
Frequency Interference). Our detectors have been designed to reduce the eects of these
interferences and we meet CSA FCC and CE requirements for these type of devices. However, there
are still circumstances and levels of interference that may cause our equipment to respond to these
interferences and cause them to react as if there has been gas detected.