The Rosemount™ 975MR multi-spectrum
infrared flame detector is based on accurately
analyzing the multi-spectral signals by three
separate IR sensors. The Rosemount 975MR
detects fuel and gas fires at long distances. For
example, this product will detect a 0.1 m2 (1 ft2)
gasoline pan fire at 65 m (215 ft) in less than five
seconds. The Rosemount 975MR also provides
the highest immunity to false alarms at such
industry leading detection range.
Product Data Sheet
February 2018
Features and benefits
Multi spectrum design - for long distance detection and
high false alarm immunity
Sensitivity selection - to ensure no zone crossover detection Automatic and manual built-in-test (BIT) - to assure
continued reliable operation
Heated window - for operation in harsh weather conditions
(snow, ice, condensation)
Multiple output options for maximum exibility
and compatibility
• Relays (3) for alarm, fault, and auxiliary
• 0–20 mA (stepped)
• HART® protocol for maintenance and asset management
• RS-485, Modbus® compatible
High Reliability - MTBF - minimum 150,000 hours Approved to Safety Integrity Level 2 (SIL 2 – TÜV) Five year warranty User programmable via HART or RS-485
Oil and gas - Offshore and onshore process facilities Reneries Petrochemical process facilities Crude oil tank terminals Automotive manufacturing facilities Aircraft hangars Power generation facilities Chemical and pharmaceutical plants Production, loading, and unloading facilities
(at highest sensitivitysetting
for 0.1m2 (1 ft2) pan re)
Response timeTypically 5 s
Adjustable time delayUp to 30 s
Sensitivity ranges4 sensitivity ranges for 0.1 m2 (1 ft2) n-heptane pan re from 15 m (50 ft) to 65 m (215 ft)
Field of viewHorizontal 100˚; Vertical 95˚
Built-in-test (BIT)Automatic (and manual)
Temperature rangeOperating: -55 ˚C to +75 ˚C (-67 ˚F to +167 ˚F)
HumidityUp to 95 % non-condensing (withstands up to 100 % relative humidity for short periods)
Heated optics To eliminate condensation and icing on the window
Electrical specifications
Operating voltage 24 Vdc nominal (18–32 Vdc)
Power consumption Standby: Max. 90 mA (110 mA with heated window)
Cable entries2 x ¾ in.- 14 NPT conduits or 2 x M25 x 1.5 mm ISO
Wiring
Electrical input protection
Electromagnetic compatibility
Electrical interface
Outputs
RelaysAlarm, fault, and auxiliary
0–20 mA (stepped)
HART® Protocol Optional HART communications on the 0–20 mA analog current (FSK) - used for maintenance, conguration changes
RS-485
Mechanical specifications
Materials
Enclosure options
MountingStainless steel 316L with electro polish nish
DimensionsDetector 101.6 x 117 x 157 mm (4 x 4.6 x 6.18 in.)
WeightDetector (stainless steel 316L) 2.8 kg (6.1 lb)
Environmental standards Meets MIL-STD-810C for humidity, salt and fog, vibration, mechanical shock, high temp, low temp
Water and dust IP66 and IP67 per EN 60529, NEMA 250 6P
Fuelm / ftFuelft / mFuelm / ft
n-Heptane
Gasoline
Diesel fuel
JP5
*0.75 m (30 in.) high, 0.25 m (10 in.) width plume re
Option: -55 ˚C to +85 ˚C (-67 ˚F to +185 ˚F)
Storage: -55 ˚C to +85 ˚C (-67 ˚F to +185 ˚F)
Alarm: Max. 130 mA (160 mA with heated window)
12–22 AWG (2.5 mm2–0.3 mm2)
According to MIL-STD-1275B
EMI/RFI protected to EN 61326-3 and EN 61000-6-3
The detector includes twelve (12) terminals with ve (5) wiring options (factory set).
SPST volt-free contacts rated 2 A at 30 Vdc
Sink (source option) conguration
Fault: 0 +1 mA
BIT fault: 2 mA ±10 %
and asset management, available in mA source output wiring options
RS-485 Modbus compatible communication link that can be used in computer controlled installations
- Stainless steel 316L with electro polish nish
- Heavy duty copper free aluminum (less than 1 %), red epoxy enamel nish (not available in FM version)
Detector (aluminum) 1.3 kg (2.8 lb)
Tilt mount 1.0 kg (2.2. lb)