gas transmitters
DESCRIPTION
The materials included in this compilation are for the use of Dwyer Instruments, Inc. potential customers and current employees as a resource only. They may not be reproduced, published, or transmitted electronically for commercial purposes. Furthermore, the Company’s name, likeness, product names, and logos, included within these compilations may not be used without specific, written prior permission from Dwyer Instruments, Inc. ©Copyright 2014 Dwyer Instruments, Inc.TRANSCRIPT
Gas Transmitters
The materials included in this compilation are for the use of Dwyer Instruments, Inc. potential customers and current employees as a resource only. They may not be reproduced, published, or transmitted electronically for commercial purposes. Furthermore, the Company’s name, likeness, product names, and logos, included within these compilations may not be used without specific,
written prior permission from Dwyer Instruments, Inc. ©Copyright 2014 Dwyer Instruments, Inc.
Overview
GSTA – CO / NO2 Gas Transmitter
CDT – CO2 Gas Transmitter
CMT200 – CO Gas Transmitter
GSTA - Introduction
Gas transmitter for detecting carbon monoxide or nitrogen dioxideCan be wall or duct mountedComes with optional remote display and can be field calibratedPurchase by type of gas detected and mounting configuration
GSTA - Key Specifications
Range: 0 to 50 PPM up to 0 to 500 PPM CO (Field Selectable) or 0 to 10 PPM NO2Accuracy: 2% F.S. for CO; 3% F.S. for NO2 at Time of CalibrationUniversal Output: Field Selectable 0 to 5 VDC / 0 to 10 VDC / 4 to 20 mA
Dip Switch Selection for Inverted Outputs and Zero Suppression
GSTA - Key Specifications
Sensor Type: Industrial Grade Electrochemical Sensor
Sensor life 3 to 5 years with recommended calibration check every 6 monthsField replaceable
Remote LCD DisplayUseful for calibration
Electrochemical Gas SensorOxidizes/reduces gas at electrodes to produce a currentOutput from the sensor is linearly proportional to the gas concentration
Allows for precise measurement at low concentrationEasier to calibrate
GSTA - Sensor Technology
GSTA - Sensor Technology
Gas enters sensor through capillary and passes through filterGas undergoes reaction on contact with Electrode ()CO2 diffuses into the air, hydrogen ions migrate to the electrolyte, and electrons generate charge on working electrode
GSTA - Sensor Technology
Secondary oxidation reaction occurs () at the counter electrodeSmall current generated proportional to gas concentrationThird electrode used is a electrical reference
GSTA - Features and Benefits
Industrial grade electrochemical sensor
Longer sensor life leads to less frequent sensor replacementsHigher accuracy at lower concentrations allow sensors to require less frequent calibrations
Field replaceable sensors Transmitters are replaced less frequently
GSTA - Features and Benefits
Remote LCD display Building occupants do not see readings that they do not understandLowers transmitter cost to customer by having one display for multiple transmittersAllows customer to know when sensor reaches end of life by displaying “Bad Sen”
GSTA - Features and Benefits
Dip switch selectable rangeReduces inventory by only needing one model for 0 to 200 PPM or 0 to 500 PPM CO
Universal outputsReduces inventory by only needing one model for 0 to 5 VDC, 0 to 10 VDC, 4 to 20 maWorks with majority of building management controllers
GSTA - Features and Benefits
Push button calibration / range selection
More precise calibration and quicker set up
Removable terminal blocksReduces installation time and cost
Multiple knockouts on housingReduces installation cost by allowing installer to run wire or conduit to nearest side of housing
GSTA – Future Additions
GSTB communicating transmitter with BACnet and ModbusGSTC master controller
Accepts multiple GSTB inputsAudible and visual alarm outputsTwo relay outputsCommunicationsProof of fan operation indication
GSTA - Applications
Underground parking garagesMonitor the exhaust gases from automobilesSignal to building management system to operate exhaust fans and high gas level warning alarms465 to 700 square meter coverage area
GSTA - Applications
Loading docksMonitor the gas levels from fork lifts and trucks
GSTA - Applications
Automobile service bays or new car dealerships
Monitor the carbon monoxide from automobile exhaust Signal to building management system to operate exhaust fans and high gas level warning alarms
GSTA - Applications
Boiler or mechanical roomsMonitor the combustion gases from gas fired boilers
CDT - Introduction
Measures carbon dioxide concentration and temperature in an indoor environmentWall and duct mounts availableCan order passive thermistor or RTD sensor for temperature output
CDT - Key Specifications
Range: 0 to 2000 PPM or 0 to 5000 PPMAccuracy: +/- 3 % of reading +/- 40 PPMOutput: Field Selectable 0 to 10(5) VDC / 4 to 20 mA for CO2 and Temperature
Optional Passive Temperature Outputs via Separate Terminal Board for Wall MountOptional Relay for CO2
CDT - Key Specifications
Sensor Type: Non-Dispersive Infrared Single Beam Dual Wavelength Technology
Self Corrects for Drift Due to Light Source AgingField Calibration Using Calibration Kit (Dwyer Calibration Gas Tanks Available For Sale in Approved Countries)
CDT - NDIR Sensor Technology
CDT - NDIR Sensor Technology
Single Beam – Single WavelengthTelaire, Sense Air (ACI, Greystone, Thermokon, and Veris use Telaire or Sense Air Sensor Modules)Single Light Source and Single Receiver with ABC Logic Self Calibration
Advantages: Lowest Cost SolutionAcceptable Accuracy For Most Applications
Disadvantages: Can’t Calibrate Itself in Buildings Occupied 24hrs / dayAdditional Error from Logic 400 PPM Assumption
CDT - NDIR Sensor Technology
Dual Beam – Single WavelengthE+E, Vulcain (Honeywell Owned), SiemensTwo Light Sources and Single Receiver Using Second Light Source as Reference
Advantages:Can Self Calibrate In Occupied BuildingsLess Expensive Sensor
Disadvantages:Doesn’t Account for Aging of Second Light Source
CDT - NDIR Sensor Technology
Single Beam – Dual WavelengthDwyer, VaisalaSingle Light Source With Two Wavelength Filters Where One Filter Monitors the Light and Other Measures CO2
Advantage:Self Calibrates in Occupied BuildingsCalibration Monitors Actual Light Aging Effect
Disadvantage:Most Expensive Of Sensor Technologies
CDT - Features and Benefits
Field Calibration with Jumper LockoutAllows Qualified Users to Adjust Calibration to Insure Most Accurate Sensor PossibleEliminates Building Occupants from Mistakenly Changing Calibration
Field Selectable OutputsEliminates Chance of Customer Ordering Incorrect ModelsAllows Transmitter to Work With Most BMS Controllers
CDT - Features and Benefits
Terminal Block On Back PlateCustomer Can Change Transmitter Without Requiring ElectricianBack Plate Can Be Installed Without Risk of Transmitter Being Damaged or Lost During Rough In
Local and Remote DisplayAllow Customer to Access Calibration and Set Up MenusCan be Configured Not to Display CO2 for Daily UseSame Remote Display for Whole BAS Wall Mount Family
CDT - Features and Benefits
On Board RTD Temperature Sensor Able to View Ambient Temperature on All Models
Large Vents in HousingAlong With Placement of Sensor, Creates More Air Flow Across Sensor For Greater Accuracy
Optional RelayCan Turn On Fan In Case CO2 Level Too High
Field Selectable Engineering UnitsUniversal Product Platform for US and Overseas Customers
CDT - Features and Benefits
Barometric Pressure CompensationAllows Users Above Sea Level to Correct For Barometric Pressure to Insure Most Accurate Reading
Output ScalingAllows Users to Achieve Greater Resolution by Using a More Custom Temperature and CO2 Range
Push Button CalibrationReduces Time it Takes to Calibrate Transmitters
Low Price (Starting at $175.00 List)Allows Customers to Bid More Competitively on Projects
CDT - Applications
Carbon Dioxide Transmitters are used as an indication of the level of occupancy in a multiuse room such as a conference room
CDT - Application
Carbon Dioxide Transmitters are commonly used in schools to insure enough fresh air is being supplied to the classrooms
GSTA Introduction
Gas transmitter for detecting carbon monoxide or nitrogen dioxideCan be wall or duct mountedComes with optional remote display and can be field calibratedPurchase by type of gas detected and mounting configuration
Key Specifications
Range: 0 to 50 PPM up to 0 to 500 PPM CO (Field Selectable) or 0 to 10 PPM NO2Accuracy: 2% F.S. for CO; 3% F.S. for NO2 at Time of CalibrationUniversal Output: Field Selectable 0 to 5 VDC / 0 to 10 VDC / 4 to 20 mA
Dip Switch Selection for Inverted Outputs and Zero Suppression
Key Specifications
Sensor Type: Industrial Grade Electrochemical Sensor
Sensor life 3 to 5 years with recommended calibration check every 6 monthsField replaceable
Remote LCD DisplayUseful for calibration
Electrochemical Gas SensorOxidizes/reduces gas at electrodes to produce a currentOutput from the sensor is linearly proportional to the gas concentration
Allows for precise measurement at low concentrationEasier to calibrate
Sensor Technology
Sensor Technology
Gas enters sensor through capillary and passes through filterGas undergoes reaction on contact with Electrode ()CO2 diffuses into the air, hydrogen ions migrate to the electrolyte, and electrons generate charge on working electrode
Sensor Technology
Secondary oxidation reaction occurs () at the counter electrodeSmall current generated proportional to gas concentrationThird electrode used is a electrical reference
Features and Benefits
Industrial grade electrochemical sensor
Longer sensor life leads to less frequent sensor replacementsHigher accuracy at lower concentrations allow sensors to require less frequent calibrations
Field replaceable sensors Transmitters are replaced less frequently
Features and Benefits
Remote LCD display Building occupants do not see readings that they do not understandLowers transmitter cost to customer by having one display for multiple transmittersAllows customer to know when sensor reaches end of life by displaying “Bad Sen”
Features and Benefits
Dip switch selectable rangeReduces inventory by only needing one model for 0 to 200 PPM or 0 to 500 PPM CO
Universal outputsReduces inventory by only needing one model for 0 to 5 VDC, 0 to 10 VDC, 4 to 20 maWorks with majority of building management controllers
Features and Benefits
Push button calibration / range selection
More precise calibration and quicker set up
Removable terminal blocksReduces installation time and cost
Multiple knockouts on housingReduces installation cost by allowing installer to run wire or conduit to nearest side of housing
GSTA Applications
Underground parking garagesMonitor the exhaust gases from automobilesSignal to building management system to operate exhaust fans and high gas level warning alarms465 to 700 square meter coverage area
GSTA Applications
Loading docksMonitor the gas levels from fork lifts and trucks
GSTA Applications
Automobile service bays or new car dealerships
Monitor the carbon monoxide from automobile exhaust Signal to building management system to operate exhaust fans and high gas level warning alarms
GSTA Applications
Boiler or mechanical roomsMonitor the combustion gases from gas fired boilers
GSTA Future Product Additions
GSTB communicating transmitter with BACnet and ModbusGSTC master controller
Accepts multiple GSTB inputsAudible and visual alarm outputsTwo relay outputsCommunicationsProof of fan operation indication
CMT200 - Introduction
Carbon Monoxide TransmitterField calibratable and field replaceable sensors that are accurate for up to 4 yearsField selectable current/voltage outputsPricing: Starts at $120.00 list
CMT200 - Key Specifications
Sensor: Field replaceable electrochemical, 4 year typical lifespanRange: 0 to 200 ppmAccuracy: ±2% of reading at the time of calibrationHousing: UV resistant polycarbonateOutput: Jumper selectable 4 to 20 mA (loop powered) or 2 to 10 V (load must be >50 KΩ)Agency Approvals: CE, RoHS
CMT200 - Electrochemical Gas Sensor
Oxidizes/reduces gas at electrodes to produce a currentOutput from the sensor is linearly proportional to the gas concentration
Allows for precise measurement at low concentrationEasier to calibrate
CMT200 - Advantages
Benefits of the electrochemical gas sensor
Linear and highly accurate outputRequires minimal powerHas a long lifetime
CMT200 - Advantages
Sensor can be field calibrated and is field replaceable
Can provide up to 4 years of accurate readings with regular calibrationCalibration can be done by using Model GCK-200CO-2000CO2 calibration gas, Model A-507A calibration adapter, and the on board span and zero potentiometers
CMT200 - Applications
Carbon monoxide is a toxic gas that is colorless, odorless, tasteless and difficult for people to detectMost commonly a byproduct of combustion in low oxygen environment
Motor vehiclesHeaters and cooking equipment that run on carbon-based fuels
Dangerous at concentrations of 100 ppm or more
CMT200 - Applications
Used in:Underground or indoor parking areas, where vehicle exhaust can lead to an accumulation of CO gasVehicle maintenance facilitiesMechanical roomsCovers 5000 to 7000 sq. ft.