L11354-01_ETC_KPIC1079E02 Datasheet, PDF (1/2 Pages) Hamamatsu Corporation – Quick Detection of Flame from Distance, Compact UV Sensor with High Sensitivity and Wide Directivity, Suitable for Flame Detectors and Fire Alarms.

FLAME SENSOR UVTRON^®
R2868
Quick Detection of Flame from Distance,
Compact UV Sensor with High Sensitivity and Wide Directivity,
Suitable for Flame Detectors and Fire Alarms.
Hamamatsu R2868 is a UVTRON ultraviolet ON/OFF detector
that makes use of the photoelectric effect of metal and the gas
multiplication effect. It has a narrow spectral sensitivity of 185 nm
to 260 nm, being completely insensitive to visible light. Unlike
semiconductor detectors, it dose not require optical visible-cut fil-
ters, thus making it easy to use.
In spite of its small size, the R2868 has wide angular sensitivity
(directivity) and can reliably and quickly detect weak ultraviolet
radiations emitted from flame due to use of the metal plate cath-
ode (eg. it can detect the flame of a cigarette lighter at a distance
of more than 5 m.).
The R2868 is well suited for use in flame detectors and fire
alarms, and also in detection of invisible discharge phenomena
such as corona discharge of high-voltage transmission lines.
APPLICATIONS
GFlame detectors for gas / oil lighters and matches
GFire alarms
GCombustion monitors for burners
GInspection of ultraviolet leakage
GDetection of discharge
GUltraviolet switching
Figure: UVTRON's Spectral Response and Various Light Sources
TPT B0009EB
100
UVTRON's
SPECTRAL
RESPONSE
SUNLIGHT
50
SPECIFICATIONS
GENERAL
Parameter
Spectral Response
Window Material
Weight
Description / Value
185 to 260
UV glass
Approx. 1.5
MAXIMUM RATINGS
Parameter
Supply Voltage
Peak Current ¹
Average Discharge Current ²
Operating Temperature
Value
400
30
1
-20 to +60
CHARACTERISTICS (at 25 °C)
Parameter
Value
Discharge Starting Voltage
(with UV radiation) (DC)
Max.
280
Recommended Operating Voltage (DC)
Background ³
Max.
Sensitivity ⁴
Typ.
325 ± 25
10
5000
Unit
nm
—
g
Unit
V
mA
mA
°C
Unit
V
V
min^-1
min^-1
GAS
FLAME
TUNGSTEN
LIGHT
0
100 200 300 400 500 600 700 800 900
WAVELENGTH (nm)
ULTRAVIOLET
VISIBLE
INFRARED
NOTE: 1This is the maximum momentary current that can be handled if its
full width at half maximum is less than 10 µs.
2If the tube is operated near this or higher, the service life is notice-
ably reduced. Use the tube within the recommended current values.
3Measured under room illuminations (approx. 500 lux) and recommen-
ded operating conditions. Note that these values may increase if the
following environmental factors are present.
(1)Mercury lamps, sterization lamps, or halogen lamps are located
nearby.
(2)Direct or reflected sunlight is incident on the tube.
(3)Electrical sparks such as welding sparks are present.
(4)Radiation sources are present.
(5)High electric field (including static field) generates across the tube.
4These are representative values for a wavelength of 200 nm and a
light input of 10 pW/cm². In actual use, the sensitivity will vary with the
wavelength of the ultraviolet radiation and the drive circuitry employed.
Subject to local technical requirements and regulations, availability of products included in this promotional material may vary. Please consult with our sales office.
Information furnished by HAMAMATSU is believed to be reliable. However, no responsibility is assumed for possible inaccuracies or omissions. Specifications are
subject to change without notice. No patent rights are granted to any of the circuits described herein. ©2008 Hamamatsu Photonics K.K.