Photoelectric Smoke Detector MIR-65 Series

DESCRIPTION:

The MIR-65 Series incorporate proven sensing technologies, together with advances in materials and electronics technology. Having a wide operating voltage of 9-33VDC, the MIR-65 Series detectors can be integrated into most Fire/Security systems. The MIR-65 Series wide voltage range family consists of photoelectric smoke, ionization smoke, and heat detectors.

Ionization Smoke Detector Head (MID-65I)

The sensing part of the ionization detector consists of two chambers - an open outer chamber with a second semi-sealed reference chamber within. Mounted in the reference chamber is a low activity radioactive foil of Americium 241 which enables current to fl ow between the inner and outer chambers when the detector is powered up. As smoke enters the detector, it causes a reduction of the current fl ow in the outer chamber and, hence, an increase in voltage measured at the junction between the two chambers. The voltage increase is monitored by the electronic circuitry which triggers the detector into alarm state at a preset threshold. A highly visible external red LED fl ashes when the detector is in operational standby and changes to steady in alarm state.

Photoelectric Smoke Detector Head (MPD-65P)

The photoelectric detector incorporates a pulsing infrared LED located in a chamber within the housing of the detector. The chamber is designed to exclude light from any external source. At an angle to the LED is a photodiode which normally does not register the column of light emitted by the LED. In the event of smoke from a fi re entering the chamber, the light pulse from the LED will be refracted into and registered by the photo-diode. If the photo-diode “sees” smoke on the two following pulses (alarm confi rmation), the detector changes into the alarm state. A highly visible external clear LED fl ashes red when the detector is in operational standby and changes to steady red in alarm state. The clear LED allows for easy fl oor level detector type identification.

Fixed and Rate-of-Rise Heat Detector Head (MHD-65-135/MHD-65-200)

The heat detector operates by using a matched pair of thermistors to sense heat. One thermistor is exposed to the ambient temperature, the other is sealed. In normal conditions the two thermistors register similar temperatures; but, on the development of a fi re, the temperature recorded by the exposed thermistor will increase rapidly, resulting in an imbalance that causes the detector to change into the alarm state. Rate-of-rise detectors are designed to detect a fi re as the temperature increases, but they also have a fi xed upper limit at which the detector will go into alarm if the rate of temperature increase has been too slow to trigger the detector earlier. A highly visible external red LED fl ashes when the detector is in operational standby and changes to steady in alarm state.

MIR-65 Series Bases

All MIR-65 Series bases have a “one-way-only” fi t. The detectors are polarity sensitive and the bases are easy to wire. All bases have an earth ground connection and accept the provided standard head locking screw. MIR-65 Series relay bases are for use with control units having resetable 4-wire detector power supply and alarm initiating circuits. Where local codes allow, they may also be used in 4-wire circuits to provide volt-free control signals to auxiliary systems such as automatic door closers.