AVENAR detector 4000 is a new range of automatic firedetectors featuring a superb accuracy and swiftness indetection. The versions with two optical sensors(dual-optical) are able to detect the lightest smoke.The range includes versions with rotaries, manuallyand automatically addressable, and versions withoutrotaries for automatic address setting.
Functions
Sensor technology and signal processing
The individual sensors can be configured in theFSP-5000-RPS programming software.
All sensor signals are analysed continuously by theinternal evaluation electronics (ISP - Intelligent SignalProcessing) and are linked with each other via aninbuilt microprocessor. The link between the sensorsmeans that the combined detectors can also be usedwhere light smoke, steam or dust must be expectedduring the course of normal operation.
Only if the signal combination corresponds to thecharacteristics of the application site, selected duringthe programming, the alarm is triggered automatically.This results in less false alarms.
In addition, the time of the sensor signals on fire andfault detection is analysed, which leads to highdetection reliability for each individual sensor.
In the case of the optical and chemical sensor, theresponse threshold (drift compensation) is activelyadjusted. Manual or time-controlled switch-off ofindividual sensors is possible for adjustment toextreme interference factors.
Optical sensor (smoke sensor)
The optical sensor uses the scattered-light method.An LED transmits light to the measuring chamber,where it is absorbed by the labyrinth structure. In theevent of a fire, smoke enters the measuring chamberand the smoke particles scatter the light from the LED.The amount of light hitting the photo diode isconverted into a proportional electrical signal.The dual-optical versions use two optical sensors withdifferent wavelengths. The Dual-Ray technology workswith an infrared and a blue LED so that lightest smokeis detected fast and reliably (TF1 and TF9 detection).
Thermal sensor (temperature sensor)
A thermistor in a resistance network is used as athermal sensor from which an analog-digital convertermeasures the temperature-dependent voltage atregular intervals.
Depending on the specified detector class, thetemperature sensor triggers the alarm status when themaximum temperature of 54 �C or 69 �C is exceeded (thermal maximum), or if the temperature rises by adefined amount within a specified time (thermaldifferential).
Chemical sensor (CO gas sensor)
The main function of the gas sensor is to detectcarbon monoxide (CO) generated as a result of a fire,but it will also detect hydrogen (H) and nitrousmonoxide (NO). The sensor signal value is proportionalto the concentration of gas. The gas sensor deliversadditional information to effectively suppressdeceptive values.
