65UV5-1004ECEX FIREYE Integrated Flame Scanner with Internal Flame Relay

The Fireye 65UV5-1004 flame scanner is a microprocessor based flame scanner utilizing an ultraviolet tube-type sensor, and electro-mechanical self-checking shutter mechanism.
The Fireye 65UV5-1004 flame scanner incorporates an internal flame relay with a fixed ON/OFF thre shold thereby eliminating the need for an external flame amplifier. Models are available with a four-second or a one-second flame failure response time (FFRT). The 65UV5-1004 model also provides an analog 4 to 20mA output referenced to flame signal strength.
The Fireye 65UV5-1004 flame scanner is powered by 24 vdc. CEX models are wired directly via a terminal rail located within the CEX housing. Suitable glands must be used to terminate the cable at the housing. The picture above depicts the CEX scanner mounted on a heater.

Fireye 65UV5 self-checking scanners are used to detect ultraviolet emissions from fossil fuel flames such as natural gas, coke oven gas, propane, methane, butane, kerosene, light petroleum distillates
and diesel fuels.

65UV5-1004ECEX

The 65UV5 scanners use a UV-eye detector. This detector is a sealed, gas filled, UV-sensitive tube containing two electrodes connected to a source of DC voltage. When UV radiation of sufficient energy falls upon the electrodes, electrons are released and the inter-electrode gas becomes conductive, resulting in an electric current flow from one electrode to the other. The current flow starts and ends abruptly and is known as an “avalanche.”
A very intense source of UV radiation will produce several hundred avalanches or pulses per second.
With less radiation there will be fewer pulses per second. Upon total disappearance of flame, the detector output ceases. Thus, the presence or absence of pulses is an indication of the presence or absence of flame; the frequency of the pulses is a measure of flame intensity. When the pulses reach a sufficient level, the internal flame relay is energized.