The new generation of radiant energy flame detectors,
SharpEye 20-20 L & 20-20 LB series, is an improved line
of Ultra Violet/Infra Red (UV/IR) optical flame detectors,
which combines state-of-the-art technology with
existing proven performance equipment. Detection
performance is controlled by a microprocessor and is
easily adapted to all environments, applications &
requirements. The result is a unique and superior flame
detector, which provides excellent detection sensitivity
with extreme immunity to false alarms. These enhanced
models were developed in light of our successful
experience in high-speed flame detection technology
for both military and commercial industrial
Both the 20-20 L & 20-20 LB are self-contained dualsensor
flame detectors designed to detect hydrocarbonbased
fuel fires and non-organic fires. The flame
detector senses energy in the short wave section of both
the ultra-violet and infrared portions of the
The sensor band pass has been carefully selected to
ensure the greatest degree of spectral matching to the
radiant energy emissions of fire, and the lowest
degree of matching to non-fire stimuli.
The UV channel incorporates a special logic
circuit that eliminates false alarms caused by
solar radiation and other non-fire UV sources.
The UV channel sensitivity is stabilized over the
working temperature range.
The IR sensor is sensitive to radiation over the
range of 2.5 to 3.0 microns. The IR channel will
register a detection signal, at the appropriate
level, when the detector’s IR sensor is exposed to
radiation on the appropriate frequency range.
Only radiation in this range lasting for a preset
time and threshold and having an intermittent
pattern characteristic to fire will register an alarm
signal. The signals from both sensors are
analyzed for frequency, intensity and duration.
Simultaneous matching of radiant energy in both
the UV & IR sensors triggers an alarm signal.
In addition to the basic alarm evaluation circuit,
the SharpEye 20-20 LB Flame Detector
• UV/IR dual-sensor
• High-speed response
• Multiple detection levels
• 20 msec response to saturated signal
• Immune to false alarms (solar blind)
• 90°/90° cone of vision
• User-programmable configuration
• Standard 4-wire connection
• 4-20mA output (source)
• FM, Cenelec/ATEX Approved
• MTBF minimum 100,000 hours
• Unitized - no separate controller required
Dimensions: 120 x 132 x 132 mm
Weight: Aluminium: 3.7 Kg
Spectral response: UV: 0.185-0.260 microns
IR: 2.5-3 microns
Detection range: 1 sq.ft. gasoline fire @ 50 ft.
1 sq. ft. n-heptane fire @ 50 ft.
1 sq. ft. diesel oil fire @ 37 ft.
1 sq. ft. 95% alcohol fire @ 37 ft.
Response time: Typical 3 seconds for a 1sq.ft. gasoline pan fire.
Time delay: Adjustable time delay up to 30 seconds.
Field of view: 90°horizontal, 90° vertical.
Built-in-test: Manual & automatic BIT in model 20-20 LB only.
Operating -40°F - 160°F
Storage -65°F - 185°F
Humidity: Relative humidity of up to 95% for the operational temperature.
Operating voltage 18-32 Vdc
Standby Max. 100 mA
Alarm Max. 125 mA
Standard two ¾” 14 NPT cable entries.
Optional two M25 x 1.5 cable entries.
Electrical input protection:
Complete electrical interface protection against reversed polarity voltage, surges, and spikes according to MIL-STD-1275.
The detector is designed and approved according to the following EMC requirements:
Electrostatic discharge IEC801-2: 1984
Conducted emission EN55022 Class A
Radiated emission EN55022 Class A
Radiated Immunity IEC801-3: 1984
EFT/B IEC801-4: 1988
*Dry contact relays:
Alarm: 2 Amps @ 30 Vdc
0.5 Amps @ 250 Vac
Accessory: 5 Amps @ 30 Vdc & 250 Vac
Fault: 5 Amps @ 30 Vdc & 250 Vac
* 4-20 mA current output:
The 4-20mA is source.
Fault: 0 ± 0.5 mA
Normal: 4 mA ± 5%
IR detection: 8 mA ± 5%
UV detection: 12 mA ± 5%
Warning: 16 mA ± 5%
Alarm: 20 mA ± 5%
Resistance loop: 100-600 Ohms