Infra-Red Transit FLAME Sensor in Stainless Steel 316 Housing

Infra-red transit flame sensors are designed to trigger an alarm if the material they are monitoring exceeds a temperature of 240°C. Sensitivities can also be set above this threshold. The sensor triggers as the material reaches the ember or flame condition. Material being transported can be monitored on conveyor systems running at speeds of between 0.5 and 6m/s.

The sensors employ enhanced infra-red monitoring technology to analyse the level of IR emissions in the narrow band of 4.2-4.7μm. As the sensor is tuned to this band it is ‘solar blind’ meaning the ‘background’ and ‘transient’ IR spectra are discriminated. This provides enhanced false alarm immunity.

Infra-Red Transit Flame Sensor for hazardous areas. IECEx/ATEX approved for Zones 1, 2 & 21, 22

This High Temperature Transit Flame Sensor monitors high temperature materials (up to 240° on highest sensitivity), being transported on conveyor systems at speeds of between 0.5 and 6m/s, and triggers as the material reaches the ember or flame condition.

The sensor employs enhanced infra-red monitoring technology that analysis the levels of IR emission in the narrow band of 4.2-4.7μm. As the sensor is tuned to this band it is “solar blind” meaning the “background” and “transient” IR spectra are discriminated. This provides enhanced false alarm immunity.

This unit is specifically designed for hazardous areas and is IECEx / ATEX approved for Zones 1, 2 & 21, 22.

Air purging from a compressed air feed is used to maintain a lens cleaning system that ensures the prevention of dust settling on the sensor window.

This unit incorporates within the unit a user programmable SIL switch. Option selection includes detector sensitivity settings, auto/manual reset sequence selection and single/coincidence voting from the two individual internal detectors for the alarm trip shutdown outputs.

The sensor air pressure and signal cable connections are fault monitored and fail safe. The controller incorporates an auxiliary fault input and common fault output contact.

Standard / Low Power Mode

The unit can be used in two principle operating modes. Either relay mode, with its own 24 Vdc power supply or in low power mode (as shown below), see datasheet for further details. The sensor is located above or beside the materials transit path (conveyor, roadway, etc.) by means of the adjustable mounting bracket and aligned such that the monitored hazard passes through the sensor’s field of view. The distance and angle of the sensor determine the width of the monitored path.

Sensitivity

The table below shows the width of the monitored product at the Lowest and Highest sensitivity settings. This is based on the sensor mounted 1m above Conveyor at 45° angle. Exact response is dependant on the emissivity factor of the monitored material, sensor orientation and target speed. 

Air Purging

All infra-red transit heat and flame sensors feature air purging from a compressed air feed. This is used to maintain a positive air pressure across the sensor window to prevent dust settling. The air supply is monitored by a pressure switch which signals a fault status if the air supply fails.

Applications

• Food Processing
• Tobacco Processing
• Conveyors
• Waste Recycling Conveyors
• Baggage Handling
• Radio Frequency Drying Systems
• Microwave Drying Systems
• Waste Drying Systems
• Drying Conveyors