Which Flame Detector do we use?

 

This guide is designed to assist those who have little or no experience with the use of Optical Flame Detectors.   Please note that this information is provided as a guide and should only be used as such.

 

Intronics offers over fifty different Flame Detectors and configurations.   Very confusing when all you wish to do is to detect flame quickly and efficiently, with minimal risk of false alarms.

 

There exist three basic Flame Detector types, ultraviolet (UV), infrared (IR) and combined ultraviolet and infrared (UV-IR).   Briefly the merits and the limitations of each are as follows:

 

UV        Merits        Fast response, typically respond to small petrol fires at in the

                                  region of 25 metres in 1 second.   Excellent for many applications

                                  but careful consideration of the location needed to prevent false     

                                  alarms.

 

             Limitations Respond to false alarm criteria such as arc welding, quartz      

                                  halogen lights (with no glass cover), lightning and other spurious     

                                  sources of UV.   Quartz sensor tube / window must be kept clean.

                                  Will not see flame through thick smoke.

 

IR          Merits         Fast ( fraction of a second) or medium (± 3 seconds) response     

                                   time depending on the exact type and application.   Sees flame     

                                   through smoke and also through a thin film of oil or other      

                                   contamination on the sensor or window including ice.   Some of     

                                   the multi sensor units are virtually false alarm free.

 

             Limitations   From the IR Flame Detectors currently available, certain units may     

                                   false alarm if pointed directly at vibrating sources of heat or if     

                                   looking at the reflections.   Other false alarm criteria exists.        

                                   Susceptibility varies depending on specific detectors.

 

UV-IR Merits           UV-IR detectors are basically a combination of both UV and IR     

                                   detectors where both must see flame before the unit will go in to     

                                   an alarm state.   These detectors are generally false alarm free,     

                                   particularly those with two or more IR sensors.

 

              Limitations Contamination of the UV sensor or window greatly reduces the     

                                   sensitivity if not totally inhibiting the function of the detector.   The     

                                   UV sensor will not permit the detector to see flame through thick     

                                   smoke and may inhibit the functioning of the UV-IR combination.

 

If in doubt, provide details of the application to the supplier and request their advice.

 

Another factor to consider is naturally price.   Do not use a low cost detector where a high specification unit is required - it could be dangerous!.   Equally, If you have a low cost limited budget application that requires a more basic Flame Detector, ensure your supplier is able to supply such a unit.

 

We repeat that this information is supplied as a guide only.   Intronics accepts no responsibility or liability of any nature resulting in any form of loss, damage or injury as a result of interpretation or mis-interpretation of the above information.

e.mail: sales@intronics.co.uk