Rosemount™ 975UR Ultraviolet Infrared Flame Detector


Rosemount™ 975UR Ultraviolet Infrared Flame Detector


Rosemount 975UR UV/IR flame detector senses radiant energy in the short wave section of both the ultraviolet and infrared portions of the electromagnetic spectrum and can detect hydrocarbon-based fuel and gas fires. The signals from both sensors are analyzed for frequency, intensity and duration. Simultaneous detection of radiant energy in both the UV and IR sensors triggers an alarm signal. The UV sensor incorporates a special logic circuit that helps prevent false alarms caused by solar radiation.


Time Constant / Response
Typically 3 s.
Ambient Temperature
Operating: -67 °F to +167 °F (-55 °C to +75 °C)
Option: -67 °F to +185 °F (-55 °C to +85 °C)
Storage: -67 °F to +185 °F (-55 °C to +85 °C)
Power Supply
Standby: Max. 90 mA (110 mA with heated window)
Alarm: Max. 130 mA (160 mA with heated window)
Stainless Steel 316L with electro polish finish
Communication Protocol
Optional HART® communications on the 0–20 mA analog current (FSK) - used for maintenance, configuration changes and asset management, available in mA source output wiring optionsRS-485 Modbus compatible communication link that can be used in computer controlled installations
Enclosure Rating
Stainless Steel 316L with electro polish finish
Heavy duty copper free aluminum (less than 1 %), red epoxy enamel finish (not available in FM version)
Detector 4"  x 4.6"  x 6.18"  (101.6 x 117 x 157 mm)
Detector (stainless steel 316L) 6.1 lb (2.8 kg)
Detector (aluminum) 2.8 lb (1.3 kg)
Tilt mount 2.2 lb (1.0 kg)

Ex II 2 GD,
Ex d e IIC T5 Gb Ex d e IIC T4 Gb
Ex tb IIIC T96 ?C Db Ex tb IIIC T106 ?C Db
(-55 °C ≤ Ta ≤ +75 °C) (-55 °C ≤ Ta ≤ +85 °C)


Class I Div. 1, Groups B, C, & D
Class II/III Div.1, Groups E, F & G


  • UV/IR Dual-Sensor
  • Automatic and manual Built-In-Test (BIT) - to assure continued reliable operation
  • Heated window - for operation in harsh weather conditions (snow, ice, condensation)
  • 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 (SIL2 – TÜV)
  • 5-Year Warranty
  • User Programmable via HART® or RS-485

Documents & Drawings

Training & Services