Emerson Rosemount 975MR, Reference Manual

Page: 15 / 74

Table 1-4: Sensitivity Range Levels
(continued)
Level Response time (sec) Sensitivity range - ft. (m) (for
1 ft.
2
(0.1 m
2
) n-heptane pan
fire)
3 8 150 (45)
4 10 215 (65)
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.
2
(0,1 m
2
) and is defined as 100 percent
sensitivity.
• For fuel fire: standard pan fire size: 1 ft.
2
(0,1 m
2
)
• 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 Percent of max. distance at each sensitivity range Max. distance
(ft. / m)
Gasoline 100% 215 / 65
n-Heptane 100% 215 / 65
JP5 70% 150 / 45
Kerosene 70% 150 / 45
Diesel fuel 70% 150 / 45
Ethanol 95% 60% 135 / 40
IPA 60% 135 / 40
Methanol 55% 115 / 35
Methane
(1)
70% 150 / 45
LPG
(1)
70% 150 / 45
Paper 38% 82 / 25
Polypropylene 55% 115 / 35
(1) 30 in. (0.75 m) high, 10 in. (0.25 m) wide plume fire
Reference Manual Introduction
00809-0100-4975 August 2019
Rosemount 975MR 15