Emerson Rosemount 975MR Reference Manual page 15

Reference Manual
00809-0100-4975
Table 1-4: Sensitivity Range Levels
Level
3
4
For some typical ambient conditions, the Zeta parameter as defined in NFPA 72 for the
detector is 0.005 (1/meter).
Note
Zeta parameters may vary significantly with changes in temperature, air pressure,
humidity, visibility conditions, etc.
Other fuels
The detector reacts to other types of fire as follows:
• The baseline fire refers to n-heptane 1 ft.
sensitivity.
• For fuel fire: standard pan fire size: 1 ft.
• For gas flame: 30 in. (0.75 m) high, 10 in. (0.25 m) wide plume fire
• Maximum response time: 10 sec.
Table 1-5: Fuel Sensitivity Ranges
Type of fuel
Gasoline
n-Heptane
JP5
Kerosene
Diesel fuel
Ethanol 95%
IPA
Methanol
Methane
(1)
LPG
Paper
Polypropylene
(1) 30 in. (0.75 m) high, 10 in. (0.25 m) wide plume fire
Rosemount 975MR
Response time (sec)
8
10
Percent of max. distance at each sensitivity range
100%
100%
70%
70%
70%
60%
60%
55%
(1)
70%
70%
38%
55%
(continued)
2 2
(0,1 m ) and is defined as 100 percent
2 2
(0,1 m )
Introduction
August 2019
Sensitivity range - ft. (m) (for
2 2
1 ft. (0.1 m ) n-heptane pan
fire)
150 (45)
215 (65)
Max. distance
(ft. / m)
215 / 65
215 / 65
150 / 45
150 / 45
150 / 45
135 / 40
135 / 40
115 / 35
150 / 45
150 / 45
82 / 25
115 / 35
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