Let’s first review the components that make up a gas detection system as it will help determine the overall architecture and design of the gas detection system.
Controller: The controller is the device that receives and displays the gas concentration and alarms from each sensor. The controller typically provides a readout of the gas concentration, audible and visual alarms, alarm relays, and analog and/or digital signal outputs. There are single-channel controllers to monitor 1 sensor and multichannel controllers to monitor many sensors. Much like a fire detection panel, the controller is usually mounted outside the monitoring area, to allow safe viewing of gas readings from a central location.
Sensors: The sensor is the device that detects and measures the gas. There are many types of sensors; each designed to detect a particular gas or group of gases. A sensor's range of detection (gas range) is usually determined by an established health or safety standard. Most sensors have a typical life of 1-4 years, but some can last longer depending on the application and type of sensor.
Transmitter (Amplifier): The transmitter is a device that conditions and/or boosts the signal from a sensor to the controller. Some sensors require a transmitter to operate while others connect directly to the controller. If a sensor is more than a few hundred feet from the controller, a transmitter is usually needed. There are exceptions to this rule so please consult our technical support group at toll-free 1-877-832-4737.
Stand-Alone Sensor/Transmitters: There are stand-alone sensor/transmitters that can be used with or without a controller. These stand-alone sensors generally have a display, alarm relays, and a signal output.
Sample Pump: Pumps may be added to a sensor to allow remote sample capability. Difficult-to-reach areas or areas that are prone to flooding are reasons to consider a sample pump.
System Considerations:
List of gases you wish to detect.
Safety monitoring or process control?
Distance between each sensor and the controller.
Gas Range and alarm settings are required for each gas.
What do you wish to control with each alarm?
What is the approximate area (cubic feet) you wish to detect gas within?
Responsibility for the use of any information contained in this e-mail is strictly and solely that of the user.
Configuring a Gas Detection System
Controller Considerations:
Is a controller needed?
Mounting Options; Wall Mount, Rack mount, Desktop?
How many alarm points (levels) are needed per sensor?
How many relays are needed for each alarm point?
What is the amperage and voltage rating of each alarm relay?
What action(s) take place at each alarm level?
How will each alarm action be initiated; Relay, analog, or digital output?
Signal Inputs are needed to communicate with each sensor.
Signal Outputs needed to communicate with DCS, SCADA, PLC, or some other device.
Environmental Factors: Moisture, high particulate (dust), aerosols, extreme temperature.
Sensor / Transmitter Considerations:
Gas type and Gas range of each sensor.
How many sensors are needed for each gas?
Sample draw or diffusion sensor?
Is sample conditioning needed; If so what type of conditioning? Example: A coalescing filter may be needed to remove excessive moisture.
Is a display needed at the sensor?
Are local alarm relays needed at the sensor?
Environmental Factors: Moisture, high particulate (dust), aerosols, extreme temperature.
Enclosure type; intrinsically safe, explosion proof, NEMA rated?
Damaging gases: Are there any gases that may be harmful to the sensor or equipment present in the environment? For example: Silicone, Leaded Fuel, Chlorine, Halogenated compounds
(Freon) can damage a catalytic combustible sensor.
Please consult our technical support group at toll-free 1-877-832-4737 with any questions
Responsibility for the use of any information contained in this e-mail is strictly and solely that of the user.