Spectrex 20/20U (UB) - UV Flame Detector - Manual (Page 14)

Spectrex Inc. - SharpEye™ UV Flame Detector Manual – TM 20/20UB Rev. E, August 2004
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3. Performance
3.1 Detection Sensitivity
Detection sensitivity is the maximum distance at which the detector will reliably
detect a specific size of fire & typical type of fuel (standard fire).
Standard Fire:
Standard fire is defined as a 1ft x 1ft (0.3m x 0.3m) Gasoline pan fire with max.
Wind speed of 6.5ft/sec (2m/sec).
Sensitivity Ranges:
The detector has two response levels:
1. Warning (Pre-alarm)
2. Alarm
For some typical ambient conditions the Zeta parameter as defined in NFPA 72
for the detector is 0.0003 (1/meter).
Note:
Zeta parameters may vary significantly with changes in temp, air pressure,
humidity, visibility conditions, etc.
Response Time:
The typical response time of the detector is 3 seconds. for 1 sq. ft. gasoline fire.
Other Fuels:
The Detector will react to other fuels in standard fire conditions at maximum
response time of 5 seconds.
The sensitivity range of other fuels varies according to the fuel type. The
percentage of the range for a fuel type that is relative to gasoline standard fire
source is given at Table 1 below.
Table 1. Response Sensitivity Ranges
Type of Fuel % of Max. Distance at Each
Sensitivity Range
Gasoline 100%
N-Heptane 100%
Alcohol 95%
75%
JP4 100%
Kerosene 75%
Diesel Fuel
75%
Methane Fire* 60%
Propane Fire* 60%
* 0.5m plume fire