Product Selection Guide Fixed Gas Detection Systems for Personnel & Equipment Safety

GDS Corp gas monitors, controllers and sensors satisfy today’s needs for safety and reliability in critical gas detection applications. Our NRTL certified systems are deployed in the following demanding applications: Petrochemical refining, transportation and storage Manufacture of flammable or toxic materials Confined space monitoring for toxic or flammable conditions Power generation Gas ownership transfer Manufacturing & storage Oxygen deficiency monitoring Spraying, spreading or coating operations Battery charging Combustion of gas or oil Indoor air quality monitoring Building return air plenums Waste water or municipal drinking water processing facilities Pulp and paper Mining

GDS Corp. 2513 Hwy 646 Santa Fe, Texas 77510 (409) 927-2980 (409) 927-4180 fax

www.gdscorp.com info@gdscorp.com

NRTL Certified Proven Reliability

Advanced Technology

Selection Criteria Use this guide to help select the best products for your application. The most successful installations match components to the environmental and operational needs of the system and user. This guide asks questions that can help you identify the correct components for your installation BEFORE YOU PURCHASE.

How to Use this Guide Before making your purchase decision, consider the following questions carefully. Read the section on sensor technology to better understand the relationship between sensor types and your expected environment. Subsequent pages offer product suggestions based on specific needs and applications, highlight possible communications and configuration options and describe our product’s NRTL certifications. For more information, please complete the system questionnaire form found on the last page of this guide. Fax or email the completed form to GDS Corp for a full review of your system’s needs.

Type of Gases Monitored What are the target gases to be monitored (Toxic,

Combustible or Mixed)?

What range of measurement will be required for each (PPM, % LEL or % by Volume) ?

Do preferences exist for specific sensor technologies (ex: Catalytic Bead or Infrared ?

How large is the area to be monitored? How many detection points are required?

Is there a need to monitor more than one gas type at each detection point?

Area Classification What are the area classifications where each device

is to be located?

If the area has a hazardous classification, is it Div 1 or Div 2, and is there a preference for an explosion-proof or intrinsically-safe installation?

Environmental Considerations Are detection points indoors or outdoors?

What is the expected range of ambient temperature extremes?

What is the typical relative humidity?

Are the measurement points at sea level or at higher altitude?

Is there particulate matter in the ambient environment?

Are there other reactive or corrosive compounds present with the target gas?

Operational Considerations Do sensors require remote mounting away

from the monitor, mounting to a duct or plenum, process sample cover, splash guard or remote calibration fitting?

If located in a hazardous area, should the monitor provide non-intrusive calibration?

Is an RS-485 MODBUS interface required?

Is a multi-channel controller needed to localize alarm and display functions?

Are there any specialized alarm event requirements?

Is a PC-based Human-Machine Interface (HMI) required for data display and collection?

Gas Detection for Personnel & Equipment Safety Sensor Technologies Electrochemical sensors (“E-chem”) identify low levels of toxic gases; catalytic bead (“cat-bead”) and Infrared sensors detect combustible gases in Lower-Explosive-Limit (LEL) or Percent-by-Volume applications; Photoionization detectors (PID) sense the presence of organic compounds and some non-organic gases. When used with the GASMAX family of gas monitors, GDS Corp. Smart Sensors maintain a record of calibration history and facilitate an estimate of sensor life remaining.

Electrochemical (E-chem) Sensors: Electrochemical sensors consist of electrodes separated by a thin layer of electrolyte, enclosed in a housing with an opening to allow gas to enter. Gas diffusing into the sensor is either oxidized or reduced at the sensing electrode and generates a positive or negative electrical current proportional to the concentration of target gas present.

Catalytic Bead Sensors: Cat-bead sensors consist of a matched pair of reference and analytical ceramic beads. The analytical bead is a tiny wire coil embedded within a bead of catalytic material. The reference bead is similar, except it does not contain catalytic material. Both beads operate in a bridge circuit that produces an output if the resistance of the analytical differs from that of the reference. The

GDS-48 Universal Sensor Assembly

equipment.

Temporary Sensitivity Loss: Catalyst absorption by certain compounds, including halogenated hydrocarbons, can result in the inhibition of normal reactions in catalytic bead sensors. The resultant loss of sensitivity is usually temporary and in most cases the sensor will recover after a period of operation in clean air.

Poisons: Over time, certain mechanisms can “poison” both E-chem and catalytic bead sensors. Solvent vapors or operation at extremely high temperatures for long periods can permanently reduce sensitivity. Some compounds, such as organic lead and silicon, can decompose on the surface of catalytic bead sensors and form a barrier over the surface. This action is cumulative and prolonged exposure will result in an irreversible decrease in sensitivity.

Oxygen Deprivation: E-chem sensors require the continued presence of oxygen to operate properly. Oxygen deprivation can be caused by exposure to large concentrations of a reactive gas or the displacement of oxygen by CO2 or other mixtures. Infrared LEL sensors do not require oxygen to detect combustible gas, whereas catalytic bead LEL sensors require the presence of oxygen to ’burn’ the gas on the catalytic bead.

Life Span: E-chem sensors must be replaced at periodic intervals to ensure continued safe monitoring. GASMAX monitors work with GDS Corp. Smart Sensors to track calibration history and display the percent of sensor life remaining.

Summary: Sensor technology continues to evolve rapidly. Improvements in sensor design, electronics and miniaturized detectors combine to offer gas detection options not available a few years ago. Always contact GDS Corp for the latest information on available gas detection equipment.

bridge is supplied with a constant voltage that heats the elements to approximately 550°C. Combustible gases are oxidized on the detector element, producing a signal proportional to the concentration of combustible gas. The reference tracks changes in temperature, pressure and humidity, which affect both elements equally.

Infrared (IR) Sensors: Infrared sensors operate on the principle that hydrocarbon gases absorb specific wavelengths of infrared light. Infrared LEL sensors are comprised of an infrared light source, light path and detector. Two wavelengths of light are compared, one that is absorbed by hydrocarbons, and one selected as a reference. The presence of hydrocarbon molecules reduces the intensity of the measurement beam and indicates the presence of combustible gas. The choice between IR or catalytic bead LEL sensors depends on specific situations that favor one over the other. For example, if hydrogen may be present, catalytic sensors are specified since infrared sensors will not detect hydrogen. On the other hand, IR sensors must be used if oxygen is not present in the gas stream. In other situations, infrared sensors may be preferred due to their longevity and better long term stability.

Photoionization (PID) Sensors: Photoionization detectors are often used to detect a wide range of organic compounds and some non-organic gases in ambient air. Molecules in the air are exposed to high energy photons created by an ultraviolet gas-discharge lamp; if the Ionization Potential (IP) of the molecule is lower than the energy of the photons, the molecule is ionized and the resulting current flow can be measured. The output signal is proportional to the concentration of ionizable molecules in the detector’s chamber and thus serves as a measure of

concentration. It is important to note that PID sensors will detect any ionizable molecules with an ionization potential (IP) less than the IP of the supplied UV lamp; additional electrochemical sensors may be required if it is necessary to further determine the components of a given gas mixture.

Environmental Impact

Cross Sensitivity Effect: In many cases, sensors show a cross-sensitivity to gases other than the designated target gas. This effect may be desirable since interfering gases are often also toxic or combustible. In cases where cross-sensitivity is not desired, filters may be available to remove the interfering gas.

Temperature: While chemical reactions slow as temperature drops, GASMAX II monitors maintain the desired reaction rates in toxic or O2 sensors under extremely cold conditions. The GASMAX II monitor also offers an “ARCTIC MONITOR” option that enables operation to –55°C. GDS-IR and SmartIR infrared LEL sensors have built-in compensation that eliminates drift due to variation in ambient temperature.

Humidity: Over extended periods, very low (< 15%) or high (> 90%) relative humidity may impact E-chem sensor life as the water content in the cell material changes. In these cases, solid-state MOS sensors may be preferred over E-chem sensors.

Electrical Interference: As in the case of all sensitive electronic equipment, gas detection sensors, monitors and controllers should be mounted as far as possible from machinery that generates electrical interference. The GDS-49 is especially designed to transmit signals from E-chem sensors over long distances. GDS Corp. cat-bead and infrared sensors can typically be placed 1000s of feet from controllers or monitors. Proper grounding techniques should always be followed when installing gas detection

GASMAX II + SmartIR Infrared LEL Monitor

Toxic Gas / O

xygen Monitoring

Partial list of available gases: Acetic Acid Acetone Ammonia Arsine Benzene Butadiene Carbon Dioxide Carbon Monoxide Chlorine Chlorine Dioxide Diesel Fuel Ethanol Ethylene Oxide Fluorine Gasoline Heptane Hydrazine Hydrogen Hydrogen Chloride Hydrogen Cyanide Hydrogen Fluoride Hydrogen Sulfide Isobutane Mercaptan Nitric Oxide Nitrogen Dioxide Oxygen Ozone Phosgene Silane Sulfur Dioxide Tetrahydrothiophene

GASMAX / EC Gas Monitor LCD display with trend / engineering units Smart Sensor interface Flashing LED alarm indicators Intrinsically safe installation option

GDS-49 Sensor Transmitter Remote mounting for Toxic sensor Intrinsically safe installation option

GASMAX II Gas Monitor (E-chem) GASMAX II Gas Monitor w/ PID for Organics GASMAX II Gas Monitor w/ SmartIR GASMAX IIx Wireless Gas Monitor 10-30VDC; 4-20mA outputs Smart Sensor interface Backlit LCD display with trend / engineering units Optional 5A relays & MODBUS or isolated 4-20mA output Optional dual channel (one toxic + 1 LEL) Optional 900Mhz spread spectrum wireless modem

C2 Two Channel Controller 85-240VAC or 24VDC Two sensor channels support Toxic / LEL Supports both Local and Remote sensors Graphic bar graph, trends & engineering units Two relay outputs for HORN, HIGH, WARN or FAULT Optional MODBUS slave interface

C1 16 Channel Controller 10-30VDC or 85-240VAC Up to 16 direct Analog or 4-20mA remote sensor inputs Up to 16 4-20mA outputs Up to 48 relays + common relays Relay programming allows unique alarm setups

M1/EC Gas Monitor 19-30VDC (12V available) LCD display with engineering units

Multiple Points

No Local Readout

Single Point

Local Sensor

Readout

Advanced Features

Local Sensor

Readout

Centralized Sensor

Readout

External Power

Remote Sensors

Local Sensors

E-CHEM PID or SmartIR

GDS-49 GDS-48 with PID or SmartIR

GDS-49 GDS-48 with PID or SmartIR

Remote Sensors

Local Toxic, PID or

Smart IR

GASMAX / ECx Wireless Gas Monitor LCD display with trend / engineering units Smart Sensor interface Flashing LED alarm indicators. 6 Month Battery Life 900Mhz spread spectrum wireless modem utilizing MODBUS® protocol

Self / Loop Power

Com

bustible Gas M

onitoring

Partial list of available gases: Hydrocarbon mixtures Carbon Monoxide Acetone Butane Ethane Ethylene Hexane Hydrogen Methane LPG Pentane Propane Others by special request…

GASMAX II Gas Monitor w/ GDS-IR GASMAX II Gas Monitor w/ Cat Bead GASMAX II Gas Monitor w/ Smart IR GASMAX IIx Wireless Gas Monitor 10-30VDC; 4-20mA output 0-100% LEL 0-100% LEL & 0-100% by volume (Smart IR) Backlit LCD display with trend / engineering units Flashing LED alarm indicators Smart Sensor Interface Optional 5A relay; MODBUS; isolated 4-20mA output Optional two-channel version combines on channel LEL and one channel Toxic Optional 900Mhz spread spectrum wireless modem

M1/LEL Gas Monitor w/ Cat Bead 19-30VDC (12V available); 4-20mA output 0-100% LEL Optional 5A relay or MODBUS or isolated 4-20mA output

GDS-IR 18-32 VDC; 4-20mA output 0-100%LEL; optional Propane, Methane and others

Multiple Points

No Sensor Readout

Single Point

Local Sensor

Readout1

Local Sensor

Readout

Centralized Sensor

Readout

C1 16 Channel Controller 10-30VDC or 85-240VAC Up to 16 direct Analog or 4-20mA remote sensor inputs Up to 16 4-20mA outputs Up to 48 relays + common relays Relay programming allows unique alarm setups

Remote Sensors

C2 Two Channel Controller 85-240VAC or 24VDC Two sensor channels support Toxic / LEL Supports both Local and Remote sensors Graphic bar graph, trends & engineering units Two relay outputs for HORN, HIGH, WARN or FAULT Optional MODBUS slave interface

Local or Remote Sensors

GDS-IR

GDS-IR

GDS-IR

CAT-BEAD

SMART IR

GDS-48 Remote cat-bead LEL,

Smart IR

GDS-48 Remote cat-bead LEL,

Smart IR

Com

bined Toxic / O2 / C

ombustible

GASMAX II Dual Channel Gas Monitor GASMAX IIx Dual Channel Wireless Gas Monitor 10-30VDC; dual 4-20mA outputs Backlit LCD display with trend / engineering units Smart Sensor interface for local sensors Flashing LED alarm indicators Optional 5A relays & MODBUS or dual isolated 4-20mA output Shown with dual local sensor head assembly Optional 900Mhz spread spectrum wireless modem

Two sensors: any combination

of LEL & toxic

Up to sixteen remote

sensors; most

combinations of toxic and

LEL

Remote Sensors Only

GDS-IR Remote

LEL

GDS-49 Remote

Toxic

C1 16 Channel Controller 10-30VDC or 85-240VAC Up to 16 direct Analog or 4-20mA remote sensors Up to 16 4-20mA outputs Up to 48 relays + common relays Relay programming allows unique alarm setups

Local or Remote Sensors

GDS-IR Remote

LEL

GDS-49 Remote

Toxic

C2 Two Channel Controller 85-240VAC or 24VDC Two sensor channels support Toxic / LEL Supports both Local and Remote sensors Graphic bar graph, trends & engineering units Two relay outputs for HORN, HIGH, WARN or FAULT Optional MODBUS slave interface

Local Toxic,

Cat Bead or Smart

IR

Local or Remote Sensors

GDS-IR Remote

LEL

GDS-49 Remote

Toxic (>25ft)

Local toxic, cat-

bead LEL,

Smart IR or PID

One toxic sensor & one LEL sensor; remote toxic

sensors located within

25 feet

GDS-48 Remote toxic, cat-bead LEL,

Smart IR, PID

GDS-48 Remote toxic, cat-bead LEL,

Smart IR, PID

GDS-48 Remote cat-bead LEL, Smart IR, PID

Real-Tim

e Process Analyzers

GDS Corp Custom Analyzer

One-of-a-Kind Applications

Contact GDS Corp for more

information

GDS Corp Full Custom

Systems Design

Contact GDS Corp for more

information

GDS Corp Pipeline Stream Analyzer:

Single or Dual Channel H2S, Oxygen, CO2, Other Input Stream Conditioning

Class 1 Div 1 or Class 1 Div 2

GDS Corp Pipeline Stream Analyzer 10-30VDC or 110VAC; dual 4-20mA outputs Local LCD display with trend / engineering units Flashing LED alarm indicators Optional 5A relays & MODBUS or dual isolated 4-20mA output Optional 900Mhz spread spectrum wireless modem

160 Point Deluge Controller 10 C1 Controllers 160 remote catalytic bead LEL sensors Integrated relay control logic C1 modular design facilitates easy wiring layout

To request a quote for your application, please fill out the PSA System Data Form on

the last page of this Product Selection Guide

Com

munications O

ptions

4-20mA

4-20mA

RS-485 MODBUS

GDS-49 Toxic Only

GASMAX/EC, II, M1 or GDS-IR LEL / Toxic

M1 or GASMAX II Only

C1 Protector Controller 16 Channels

4-20mA Current Loop: Unidirectional analog Sensor reading + sensor life

RS-485 MODBUS: Bi-directional Digital 9600 bits/sec Sensor reading + sensor life

4-20mA

RS-485 MODBUS

Existing Distributed Control

System

C1 Protector HMI Visualization & Data Historian Software

Local Alarms

Local Alarms

Existing Distributed Control

System 4-20mA

RS-485 MODBUS 4-20mA

Existing Distributed Control

System

GASMAX/EC, II, M1 or GDS-IR

LEL, Toxic or Organic

C2 Protector Controller 2 Channels

GDS-49 Toxic Only

GDS-49 Toxic Only

GDS-54 Loop Powered Indicator

Local Sensors

GDS-48 Catalytic Bead LEL, Smart IR,

or PID

GDS-48 Cat-bead LEL, Smart IR, PID

Direct cat bead input

WIRELESS

(Wired or Wireless)

All specifications subject to change without notice. © 2006 Global Detection Systems Corp. All Rights Reserved

NRTL* Approvals

* Important—Intrinsically Safe installations require IS barrier #10-0263 (MTL

7787) or equivalent

C1 Protector Sixteen Channel Controller CSA Approved C22.2 No 1010.1 & 152 for combustibles & ISA S82.02; UL 1604 / C22.2 No 213 (Div 2 Grp A, B, C, D); EN55011 & EN61000 (CE Mark) Available in standard panel mount, NEMA 4X enclosure for Class 1, Div 2 (Groups A, B, C, D) and NEMA 7 explosion proof enclosure for Class 1, Div 1 (Groups B, C, D)

C2 Protector Two Channel Controller CSA Approved C22.2 No 1010.1 & 152 for combustibles & ISA S82.02; UL 1604 / C22.2 No 213; EN55011 & EN61000 (CE Mark) Available in NEMA 4X enclosure for Class 1, Div 2 (Groups A, B, C, D) or NEMA 7 explosion proof enclosure for Class 1, Div 1 (Groups B, C, D)

GASMAX / EC Gas Monitor CSA Approved GASMAX for Class 1, Div 1 & 2 (Groups B, C, D) Exia. Suitable for Explosion Proof installations. CSA Approved GASMAX for Class 1, Div 1 & 2 (Groups A, B, C, D). Suitable for Intrinsically Safe installations only*

M1 Gas Monitor CSA Approved C22.2 No 1010.1 & 152 for combustibles & ISA S82.02 Instrument enclosure suitable for Class 1, Div 1 & 2 (Groups B, C, D) and Class 2, Div 1 & 2 (Groups E, F, G). NEMA 3, 4, 7, BCD, 9 EFG, CENELEC - EEx d II B IP66.

GASMAX II Gas Monitor CSA Approved GASMAX for Class 1, Div 1 & 2 (Groups B, C, D) Suitable for Explosion Proof installations.

GDS-49 Sensor Transmitter CSA Approved 10-0248 (GDS-49) for Class 1, Div 1 & 2 (Groups B, C, D) Exia. Suitable for Explosion Proof and Intrinsically Safe installations* CSA Approved for Class 1, Div 1 & 2 (Groups A, B, C, D). Suitable for Intrinsically Safe installations*.

GDS-IR Infrared Combustible Gas Detector CSA Approved C22.2 No 152; approved for Class 1, Div 1 (Groups B, C, D).

Important: The final selection and placement of monitors, detectors, alarms and readouts in any gas detection system is extremely critical to safety. Only experienced and qualified personnel who are familiar with the application and all applicable regulations and best engineering practices

* Nationally Recognized Testing Laboratory

GDS Corp. Gas Detection System Data Form

Concentration

Number of Points

Target Gas

Local Display (y/n)?

Local Alarms (y/n)?

Indoor / Outdoor?

Max ambient temp?

Min ambient temp?

Typical % humidity?

Area Classification (Div 1 Class 1, Div 1

Class 2, Non-hazardous or Other)

Intrinsically Safe Installation* (y/n)?

Communications (4-20mA, Modbus, Wireless or Other)

Fax to GDS Corp. at (409) 927-4180 or email to info@gdscorp.com For more information, please contact our sales department at (409) 927-2980

Gas #1 Gas #2 Gas #3 Gas #4

Special Requirements

Any Other Gases Present?

Contact Information

Name

Company

Address

City, State

Phone

Fax

Email Pr

efer

ence

Project Name: Date:

Application:

Fax to GDS Corp. at (409) 927-4180 or email to info@gdscorp.com For more information, please contact our sales department at (409) 927-2980

GDS Corp. Process Analyzer System Data Form

Contact Information

Name

Company

Address

City, State

Phone

Fax

Email

Sales Rep

Pref

eren

ce

Installation Specifications

Indoors or Outdoors Ambient Temp Range Distance to Stream Source Enclosure Material Enclosure Window Area Classification Utilities Available Compressed Air (y/n)? Size / Weight Limits Discharge to ATM (y/n)? Background sulphur or mercaptans?

Project Name:

Input Parameters

Target Gas 1

Target Gas 1 Range

Target Gas 2

Target Gas 2 Range

Stream Inlet Temp

Stream Inlet Pressure

Stream Inlet Dew Point

Stream Inlet Saturation

Output Specifications

Communications

Response Time

Accuracy (FS)

Alarm Set Points

Display

Alarm Indicators

Gas Component Normal % Range:

1

2

3

4

5

6

7

8

Stream Components

Additional Comments

Date: Stream Name:

Application:

Wet / Dry

4-20mA MODBUS Isolated 4-20mA

Local Display No Local Display

Local Relays No Local Relays

Light Stack No Light Stack

Sounder No Sounder

None NEMA 4 NEMA 4 SS Other

Window No Window

110VAC 220VAC 24VDC 12VDC Solar

GDS Corp. 2513 Hwy 646 Santa Fe, Texas 77510 (409) 927-2980 (409) 927-4180 fax

www.gdscorp.com info@gdscorp.com