Rosemount Analytical 975UF Operating Manual

Rosemount™ 975UF

Ultra Fast Ultraviolet Infrared Flame Detector

Reference Manual

00809-0100-4977, Rev E

April 2018

Legal Notice

The flame detector described in this document is the property of Rosemount.

No part of the hardware, software, or documentation may be reproduced, transmitted, transcribed, stored in a retrieval system, or
translated into any language or computer language, in any form or by any means, without prior written permission of Rosemount.

While great efforts have been made to ensure the accuracy and clarity of this document, Rosemount assumes no liability resulting
from any omissions in this document or from misuse of the information obtained herein. The information in this document has been
carefully checked and is believed to be entirely reliable with all of the necessary information included. Rosemount reserves the right
to make changes to any products described herein to improve reliability, function, or design and reserves the right to revise this
document and make changes from time to time in content hereof with no obligation to notify any persons of revisions or changes.
Rosemount does not assume any liability arising out of the application or any use of any product or circuit described herein; neither
does it convey license under its patent rights or the rights of others.

WARNING!

All individuals who have or will have responsibility for using, maintaining, or servicing the product should read this manual carefully.
The detector is not field repairable due to the meticulous alignment and calibration of the sensors and the respective circuits. Do not
attempt to modify or repair the internal circuits or change their settings, as this will impair the system's performance and void the
Rosemount product warranty.

Warranty

1. Limited Warranty . Subject to the limitations contained in Section 2 (Limitation of Remedy and Liability) herein, Seller
warrants that (a) the licensed firmware embodied in the Goods will execute the programming instructions provided by
Seller; (b) that the Goods manufactured by Seller will be free from defects in materials or workmanship under normal use
and care; and (c) Services will be performed by trained personnel using proper equipment and instrumentation for the
particular Service provided. The foregoing warranties will apply until the expiration of the applicable warranty period.
Sensors and detectors are warranted against defective parts and workmanship for 24 months from the date of purchase and
other electronic assemblies for 36 months from the date of purchase. Products purchased by Seller from a third party for
resale to Buyer (Resale Products) shall carry only the warranty extended by the original manufacturer. Buyer agrees that
Seller has no liability for Resale Products beyond making a reasonable commercial effort to arrange for procurement and
shipping of the Resale Products. If Buyer discovers any warranty defects and notifies Seller thereof in writing during the
applicable warranty period, Seller shall, at its option, (i) correct any errors that are found by Seller in the firmware or
Services; (ii) repair or replace FOB point of manufacture that portion of the Goods found by Seller to be defective; or (iii)
refund the purchase price of the defective portion of the Goods/Services. All replacements or repairs necessitated by
inadequate maintenance; normal wear and usage; unsuitable power sources or environmental conditions; accident; misuse;
improper installation; modification; repair; use of unauthorized replacement parts; storage or handling; or any other cause
not the fault of Seller, are not covered by this limited warranty and shall be replaced or repaired at Buyer's sole expense, and
Seller shall not be obligated to pay any costs or charges incurred by Buyer or any other party except as may be agreed upon
in writing in advance by Seller. All costs of dismantling, reinstallation, freight and the time and expenses of Seller's personnel
and representatives for site travel and diagnosis under this limited warranty clause shall be borne by Buyer unless accepted
in writing by Seller. Goods repaired and parts replaced by Seller during the warranty period shall be in warranty for the
remainder of the original warranty period or 90 days, whichever is longer. This limited warranty is the only warranty made by
Seller and can be amended only in a writing signed by an authorized representative of Seller. The limited warranty herein
ceases to be effective if Buyer fails to operate and use the Goods sold hereunder in a safe and reasonable manner and in
accordance with any written instructions from the manufacturers. THE WARRANTIES AND REMEDIES SET FORTH ABOVE ARE
EXCLUSIVE. THERE ARE NO REPRESENTATIONS OR WARRANTIES OF ANY KIND, EXPRESSED OR IMPLIED, AS TO
MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE OR ANY OTHER MATTER WITH RESPECT TO ANY OF THE GOODS
OR SERVICES.

2. Limitation of Remedy and Liability SELLER SHALL NOT BE LIABLE FOR DAMAGES CAUSED BY DELAY IN PERFORMANCE. THE
REMEDIES OF BUYER SET FORTH IN THE AGREEMENT ARE EXCLUSIVE. IN NO EVENT, REGARDLESS OF THE FORM OF THE
CLAIM OR CAUSE OF ACTION (WHETHER BASED IN CONTRACT INFRINGEMENT, NEGLIGENCE, STRICT LIABILITY, OTHER
TORT, OR OTHERWISE), SHALL SELLER'S LIABILITY TO BUYER AND/OR BUYER'S CUSTOMERS EXCEED THE PRICE TO BUYER
OF THE SPECIFIC GOODS MANUFACTURED OR SERVICES PROVIDED BY SELLER GIVING RISE TO THE CLAIM OR CAUSE OF
ACTION. BUYER AGREES THAT IN NO EVENT SHALL SELLER'S LIABILITY TO BUYER AND/OR BUYER'S CUSTOMERS EXTEND TO
INCLUDE INCIDENTAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES. THE TERM "CONSEQUENTIAL DAMAGES" SHALL INCLUDE,
BUT NOT BE LIMITED TO, LOSS OF ANTICIPATED PROFITS, REVENUE OR USE AND COSTS INCURRED INCLUDING WITHOUT
LIMITATION FOR CAPITAL, FUEL AND POWER, AND CLAIMS OF BUYER'S CUSTOMERS.

Technical support

To get technical support for this product, contact your local Rosemount representative or the Rosemount Technical Support
department at [phone] or [e-mail]

Return of material

To expedite the repair and return of this product, proper communication between the
customer and the factory is important.

Before returning a product for repair, call [phone] or email [e-mail] for a return material authorization
(RMA) number.

On the return of equipment, provide the following information:

1. RMA number provided to you by Emerson

2. Company name and contact information

3. Purchase order from your company authorizing repairs of request for quote

Ship all equipment prepaid to:
Emerson Automation Solutions
Rosemount
8200 Market Blvd
Chanhassen, MN 55317
Mark all packages with "Return for Repair" and include the RMA number.

Pack items to protect them from damage and use anti-static bags or aluminum-backed cardboard as protection from electrostatic
damage.

All equipment must be shipped prepaid. Collect shipments will not be accepted.

Release history

Rev Date Revision History

A January 2016 First release

B June 2016 Edited Table 1-3, Table D-1, and Table D-3.

C March 2017 Approvals updates

D March 2018 Approval and flame simulator information update

Abbreviations and acronyms

Abbreviation or acronym Definition

ATEX Atmospheric explosives

AWG American wire gauge

BIT Built-in test

EMC Electromagnetic compatibility

EOL End of line

FOV Field of view

®

HART

Highway addressable remote transducer - communication protocol

IAD Immune at any distance

IECEx International Electrotechnical Commission Explosion

IPA Isopropyl alcohol

IR Infrared

JP5 Jet fuel

Latching Refers to relays remaining in the ON state even after the ON condition has

been removed.

LED Light emitting diode

LPG Liquefied petroleum gas

mA Milliamps (0.001 amps)

®

Modbus

Master-slave messaging structure

N.C. Normally closed

N .O. Normally open

N/A Not applicable

NFPA National Fire Protection Association

NPT National pipe thread

PN Part number

SIL Safety integrity level

UNC Unified coarse thread

Vac Volts alternating current

Vdc Volts direct current

Contents

Contents

Chapter 1 Introduction .................................................................................................................. 1

1.1 Overview ..................................................................................................................................... 1

1.2 Model and types .......................................................................................................................... 1

1.3 Features and benefits .................................................................................................................. 4

1.4 Principles of operation .................................................................................................................5

1.4.1 Detection principles ......................................................................................................5

1.4.2 Heated optics ................................................................................................................6

1.4.3 HART protocol .............................................................................................................. 6

1.4.4 RS-485 Modbus .............................................................................................................7

1.4.5 Product certifications ....................................................................................................7

1.5 Performance considerations ........................................................................................................9

1.5.1 Detection sensitivity ..................................................................................................... 9

1.5.2 Cone of vision ............................................................................................................. 10

1.5.3 False alarms prevention .............................................................................................. 12

1.5.4 Visual indicators ..........................................................................................................13

1.5.5 Output signals ............................................................................................................ 13

1.5.6 Detector status ...........................................................................................................14

1.6 Internal detector tests ............................................................................................................... 16

1.6.1 Continuous feature test .............................................................................................. 16

1.6.2 Built-in test (BIT) ......................................................................................................... 17

Chapter 2 Installing the detector ..................................................................................................19

2.1 General guidelines .....................................................................................................................19

2.2 Unpacking the product ..............................................................................................................20

2.2.1 Checking the product type ..........................................................................................20

2.3 Required tools ........................................................................................................................... 20

2.4 Certification instructions ........................................................................................................... 21

2.5 Install cables ..............................................................................................................................22

2.5.1 Conduit installation .....................................................................................................22

2.6 Install the tilt mount (PN 00975-9000-0001) .............................................................................22

2.6.1 Tilt mount assembly ....................................................................................................23

2.7 Connecting the detector ........................................................................................................... 26

2.7.1 Verify the detector wiring ........................................................................................... 28

2.8 Configuring your detector ......................................................................................................... 29

2.8.1 Alarm delay .................................................................................................................29

2.8.2 Address setup ............................................................................................................. 30

2.8.3 Function setup ............................................................................................................30

2.8.4 Heated optics ............................................................................................................. 30

Chapter 3 Operating the detector ................................................................................................ 31

3.1 Powering up .............................................................................................................................. 31

3.2 Safety precautions .....................................................................................................................31

3.2.1 Default function settings .............................................................................................32

3.3 Testing procedures ....................................................................................................................32

3.3.1 Automatic built-in test ................................................................................................33

3.3.2 Testing with flame simulator - FS-UVIR-975 ................................................................ 33

Chapter 4 Maintenance and troubleshooting ............................................................................... 35

Reference Manual i

Contents

4.1 Maintenance ............................................................................................................................. 35

4.1.1 General procedures .....................................................................................................35

4.1.2 Periodic procedures .................................................................................................... 35

4.1.3 Keeping maintenance records .....................................................................................36

4.2 Troubleshooting ........................................................................................................................37

Appendices and reference

Appendix A Specifications ...............................................................................................................39

A.1 Technical specifications .............................................................................................................39

A.2 Electrical specifications ..............................................................................................................39

A.3 Outputs .....................................................................................................................................40

A.4 Approvals .................................................................................................................................. 42

A.5 Mechanical specifications ..........................................................................................................43

A.6 Environmental specifications .....................................................................................................43

Appendix B Wiring instructions ...................................................................................................... 45

B.1 General instructions for electrical wiring ....................................................................................45

B.1.1 Calculation formula .....................................................................................................46

B.2 Typical wiring configurations .....................................................................................................47

Appendix C RS-485 communication network .................................................................................. 53

C.1 RS-485 overview ........................................................................................................................53

Appendix D Accessories ..................................................................................................................55

D.1 Flame simulator - FS-UVIR-975 .................................................................................................. 55

D.1.1 Ordering information ..................................................................................................56

D.1.2 Unpacking .................................................................................................................. 56

D.1.3 Operating instructions ................................................................................................56

D.1.4 Range ......................................................................................................................... 57

D.1.5 Charging the battery ...................................................................................................58

D.1.6 Battery replacement ................................................................................................... 59

D.1.7 Technical specifications .............................................................................................. 59

D.2 Tilt mount - PN 00975-9000-0001 .............................................................................................60

D.3 Duct mount - PN 00975-9000-0002 .......................................................................................... 61

D.4 Cone viewer - PN 00975-9000-0006 .......................................................................................... 63

D.5 Air shield - PN 00975-9000-0005 ...............................................................................................64

Appendix E SIL-2 features ............................................................................................................... 65

E.1 Rosemount 975UF Ultra Fast Ultraviolet Infrared Flame Detector .............................................. 65

E.1.1 Safety relevant parameters ......................................................................................... 65

E.1.2 Guidelines for configuring, installing, operating, and service. ..................................... 65

ii Rosemount 975UF

1 Introduction

1.1 Overview

The Rosemount 975UF senses radiant energy in the short wave section of both the
ultraviolet and infrared portions of the electromagnetic spectrum. The IR sensor operates
at a wavelength of 2.5 to 3.0 µm, giving the flame detectors the ability to detect
hydrocarbon-based fuel and gas, hydroxyl, and hydrogen fires, as well as metal and
inorganic fires. The Rosemount 975UF Flame Detector has a high-speed response, 20
milliseconds, to flash fires or explosions.

All Rosemount 975 series detectors include a heated optical window for improved
performance in icing, snow, and condensation conditions.

Detection performance can be easily adapted to all environments, applications, and
requirements by changing the detector's configuration parameters. Adjusting these
parameters, as well as performing other maintenance and monitoring tasks, is possible by
means of RS-485 based Modbus communication or HART communication (in models with
0-20 mA output).

Introduction

1.2

The detector enclosure is ATEX certified Exd flameproof with an integral, segregated, rear,
Exe terminal compartment (avoiding exposure of the sensors and electronics to
surrounding environment). Hence the combined approval:

Ex II 2G D
Ex db eb op is IIC T4 Gb
Ex tb op is IIIC T96 °C Db

(-55 °C ≤ Ta ≤ +75 °C)

or

Ex II 2G D
Ex db eb op is IIC T4 Gb
Ex tb op is IIIC T106 °C Db

(-55 °C ≤ Ta ≤ +85 °C)

The Rosemount 975 detector is designed to operate as a stand-alone unit directly
connected to an alarm system or an automatic fire extinguishing system. The detector can
also be part of a more complex system where many detectors and other devices are
integrated through a common control unit.

Model and types

The Rosemount 975UF is provided in various configurations depending on:

• Output configurations

• Temperature

Reference Manual 1

Introduction

• Housing style

• Product certifications

The configuration detail is included in the product part number on the product label and
takes the form: 975UF-XXXXXXX, where XXXXXXX defines the model according to the
above requirements.

To modify the default or pre-ordered configuration and perform maintenance tasks,
please refer to the following manuals: HART Protocol 00809-0200-4975, the RS-485 Manual
00809-0300-4975, or 00809-0400-4975.

The standard offering represents the most common options. The starred options (⋆)
should be selected for best delivery. The expanded offering is subject to additional delivery
lead time.

Rosemount 975 Flame Detector Ordering InformationTable 1-1:

Product description

975 975 flame detector ⋆

Technology

MR Multi-spectrum infrared ⋆

HR Multi-spectrum infrared hydrogen ⋆

UF Ultra fast ultraviolet infrared ⋆

UR Ultraviolet infrared ⋆

Output configuration

Outputs Fault relay Alarm relay

1A Analog/HART/

RS-485/relays
(fault, alarm)

2A Analog/HART/

RS-485/relays
(fault, alarm)

3A Analog/HART/

RS-485/relays
(fault,alarm)

1R RS-485/relays

(fault, alarm,
auxiliary)

2R RS-485/relays

(fault, alarm,
auxiliary)

Housing style

Material Conduit entry

(1)

6A

Aluminum 3/4-in. NPT ⋆

Auxiliary re­lay Current type ⋆

Normally
closed

Normally
closed

Normally open Normally open,

Normally
closed

Normally open Normally open Normally open N/A ⋆

Normally open N/A Sink ⋆

Normally open,
normally
closed

normally
closed

Normally open Normally open N/A ⋆

N/A Source ⋆

N/A Source ⋆

2 Rosemount 975UF

Rosemount 975 Flame Detector Ordering Information (continued)Table 1-1:

(1)

8A

6S Stainless steel 3/4-in. NPT ⋆

8S Stainless steel M25 ⋆

Temperature

1 167 °F (75 °C) ⋆

2 185 °F (85 °C) ⋆

Product certifications

A1 ATEX and IECEx flameproof ⋆

A2 FM and CSA flameproof ⋆

E2 INMETRO flameproof ⋆

EM Technical Regulations Customs Union (EAC) flameproof ⋆

Typical model number: 975UF1A6A1A1

(1) Aluminum housing is not available in FM/CSA product certification.

Aluminum M25 ⋆

Introduction

Reference Manual 3

Introduction

Spare Parts and AccessoriesTable 1-2:

Part number Description

00975-9000-0001 Tilt mount ⋆

00975-9000-0002 Duct mount ⋆

00975-9000-0003 Weather cover (plastic) ⋆

00975-9000-0004 Weather cover (stainless steel) ⋆

00975-9000-0005 Air shield ⋆

00975-9000-0006 Cone viewer ⋆

00975-9000-0007 2-in. pipe mount ⋆

00975-9000-0008 3-in. pipe mount ⋆

00975-9000-0009 Flame simulator kit (for 975MR) ⋆

00975-9000-0010 Flame simulator kit (for 975UF and 975UR) ⋆

00975-9000-0011 USB RS-485 harness kit ⋆

00975-9000-0012 Spare battery pack for use with flame simulator ⋆

00975-9000-0013 Flame simulator kit (for 975HR) ⋆

00975-9000-0014 4-in. pipe mount ⋆

00975-9000-0015 Spare battery charger for use with flame simulator ⋆

1.3

NOTICE

Output configuration 1A is default. The mA sink output can be altered to source type, with a link
between terminals 1 and 8. No other output configurations can be changed on site.

For example, product number 975UF3A8S2A1 has the following options:

• Output configuration: 3A (analog/HART/RS-485/relays, fault N.O., alarm N.O./N.C.)

• Housing style: 8S (stainless steel - M25 conduit entry)

• Temperature: 2 (185 °F [85 °C])

• Approvals: A1 (ATEX and IECEx flameproof)

NOTICE

Check your specific part numbers against the information in Section 2.2.1.

Features and benefits

The flame detector has the following features and benefits.

• UV/IR dual sensor.

• High speed response: twenty milliseconds response to flash fire

• Built-in test (BIT): automatic (see Section 1.6.2)

4 Rosemount 975UF

• Heated window: prevents effects of icing, snow, and condensation.

• Electrical interface:

- Dry contact relays.

- Communication network RS-485.

- 0-20 mA output.

• HART protocol: communication protocol (see Section 1.4.3).

• Exde: integral junction box for easy wiring.

• SIL-2: TÜV approved.

• Hazardous area certification: ATEX, IECEx, and FM

• Functionality approval:

- EN54-10 approved by VdS.

- FM approved per FM3260.

• Accessories are approved as part of ATEX and IECEx approval.

Introduction

1.4 Principles of operation

1.4.1 Detection principles

The Rosemount 975UF Flame Detector is an electronic device designed to sense the
occurrence of fire and flames and subsequently activate an alarm or an extinguishing
system directly or through a control circuit.

The UV/IR radiation flame detector is a dual spectrum optical detector sensitive to two
separate ranges of the radiation spectrum, both of which are present in fires. The detector
monitors the protected volume by measuring the radiation intensity in it within two
frequencies of the electromagnetic spectrum, namely the ultraviolet (UV) and the infrared
(IR).

The detector integrates two dependent channels in which appropriate detection pulses
are registered and further analyzed for frequency, intensity, and duration.

Sensing elements

The IR sensor in the 975UF is sensitive to radiation over the range of 2.5 to 3.0 microns,
where the H2 emission has a unique spectral peak that enables detection of hydrocarbon
fires, gas fires, hydroxyl, and hydrogen fires, as well as metal and inorganic fires.

The UV sensor is sensitive to radiation over the range of 0.185 to 0.260 µm. The UV
channel incorporates a special logic circuit that eliminates false alarms caused by solar
radiation and other non-fire UV sources. Furthermore, the UV channel's sensitivity is
stabilized over the working temperature range.

Reference Manual 5

Introduction

Detection levels

Simultaneous detection of radiation in both the UV and the IR channels having an intensity
that exceeds the detector's preset warning level results in a Warning signal.

Simultaneous detection of radiation in both the UV and the IR channels having an intensity
that exceeds the detector's preset alarm levels results in an Alarm signal.

Simultaneous detection of radiation in both the UV and the IR channels having an intensity
that exceeds the detector's preset flash-fire detection level results in an immediate Alarm

signal.

As the present dual range and level of radiation as well as the flickering pattern are
characteristics of real fire, all other radiation sources apart from actual fire are not
detected, thus avoiding false alarms.

1.4.2 Heated optics

The Rosemount 975 flame detectors use heated optics. The heater increases the
temperature of the optical surface by 5 to 8 °F (3 to 5 °C) above the ambient temperature
to improve performance in icing, condensation, and snow conditions.

1.4.3

The heated optics can be set to one of the following:

• Off, not operating

• On continuously

• Automatic, per temperature change (default): you can define the start temperature

below which the window is heated. The default is 41 °F (5 °C). This temperature can
be defined between 32 °F (0 °C) and 122 °F (50 °C). The heating stops when the
temperature is 27 °F (15 °C) above the start temperature.

For more information, see Section 2.8.

HART protocol

The Rosemount 975 flame detectors use the HART protocol.

HART communication is a bi-directional industrial field communication protocol used to
communicate between intelligent field instruments and host systems. HART is the global
standard for smart process instrumentation, and the majority of smart field devices
installed in plants worldwide are HART-enabled. HART is available in output configurations
1A, 2A, and 3A (see Table 1-1).

Through the HART connection, you are able to perform:

• Detector setup

• Detector troubleshooting

• Detector health and status

For more details, refer to HART Manual 00809-0200-4975.

6 Rosemount 975UF

1.4.4 RS-485 Modbus

For more advanced communications, the flame detector has an RS-485 Modbus­compatible output that provides data communication from a network (up to 247
detectors) to a host computer or universal controller for central monitoring. This feature
allows for reduced installation costs, easy maintenance, and local or remote diagnostic
tools.

1.4.5 Product certifications

The flame detectors have the following certifications:

• ATEX, IECEx

• FM

• SiL-2 (TÜV)

• EN54-10

• InMetro (UL)

• TR CU/EAC

Introduction

ATEX, IECEx

The flame detector is certified to:

ATEX per SIRA 15ATEX1364X and IECEx per IECEx SIR 15.0138X.

Ex II 2G D
Ex db eb op is IIC T4 Gb
Ex tb op is IIIC T96 °C Db

(-55 °C ≤ Ta ≤ +75 °C)

or

Ex II 2G D
Ex db eb op is IIC T4 Gb
Ex tb op is IIIC T106 °C Db

(-55 °C ≤ Ta ≤ +85 °C)

The accessories: tilt mount (PN 00975-9000-0001), weather cover (PN 00975-9000-0003
(plastic) and PN 00975-9000-0004 (stainless steel)), duct mount (PN 00975-9000-0002),
and air shield (PN 00975-9000-0005), are included in the approval.

This product is available to use in hazardous zones 1 and 2 with IIC gas group vapors
present and zones 21 and 22 with IIIC dust type present.

FM

The flame detector is certified to FM explosion proof and functionality per FM3260.

• Class I, Division 1, Groups B, C, and D, T5 Ta = 85 °C.

Reference Manual 7

Introduction

• Dust ignition proof - Class II/III Division 1, Groups E, F, and G.

• Ingress protection - IP67, IP66, NEMA 250 Type 6P

• For more details, see FM Report Project ID3029553.

SiL-2 (TÜV)

The flame detector is certified to SIL-2 requirement per IEC 61508A, Chapter 3.5.12.

The alert condition according to SIL-2 can be implemented by:

• Alert signal via 0-20 mA current loop.

or

• Alert signal via alarm relay and fault relay.

For more details, see TUV Report No. 968/FSP 1223.

EN54-10

The flame detector is certified to EN54-10 and CPD.

• The detector has been tested and approved per EN54-10 by Vds.

• This test includes functional test, environmental test, EMI/EMC test, and software

check.

• For more details, see Test Report BMA 13109.

InMetro (UL)

The flame detector is in compliance with the standards ABNT NBR IEC 60079-0, ABNT NBR
IEC 60079-1, ABNT NBR IEC 60079-7, ABNT NBR IEC 60079-18, ABNT NBR IEC 60079-31,
and INMETRO decree No. 179 as or May 18th, 2010. Further details may be found on
Certificate of Compliance No. UL-BR 16.065XX.

TR CU/EAC

The flame detector is in compliance with the standard TR CU 012/2011 per:

1EX db eb op is IIC T4 Gb X
Ex tb op is IIIC T96 °C Db X

-55 °C ≤ Ta ≤ +75 °C

or

1Ex db eb op is IIC T4 Gb X
Ex tb op is IIIC T106 °C Db X

-55 °C ≤ Ta ≤ +85 °C

For more details, see TR CU certificate No. TC RU C-US MЮ 62.B05535.

8 Rosemount 975UF

1.5 Performance considerations

This section describes performance aspects of the flame detector.

1.5.1 Detection sensitivity

Detection sensitivity is the maximum distance at which the detector reliably detects a
specific size of fire and typical type of fuel (standard fire).

Standard fire

Defined as 1 ft.2 (0.1 m2) n-heptane pan fire with maximum wind speed of 6.5 ft./sec (2 m/
sec).

Sensitivity ranges

The detector has two response levels:

• Warning (Pre-alarm)

Alarm

•

Introduction

The detection distance for the Alarm level is 65 ft. (20 m) from a standard fire.

The detection distance for the Warning level is approximately 10% higher than the Alarm
distance.

For some typical ambient conditions, the Zeta parameter as defined in NFPA 72 for the
detector is 0.005 (1/meter).

NOTICE

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 m2) and is defined as 100%

sensitivity.

• For fuel fire: standard pan fire size: 1 ft.2 (1 m2)

• For gas flame: 30 in. (0.75 m) high, 10 in. (0.25 m) wide plume fire

• Maximum response time: 3 sec.

Fuel Sensitivity RangesTable 1-3:

Type of fuel Max. distance (ft. / m)

Gasoline 66 / 20

n-heptane 66 / 20

Reference Manual 9

Introduction

Fuel Sensitivity Ranges (continued)Table 1-3:

Type of fuel Max. distance (ft. / m)

JP5 50 / 15

Kerosene 50 / 15

Diesel fuel 50 / 15

IPA 43 / 13

(1)

LPG

Polypropylene 43 / 13

Hydrogen

(1)

Methanol 26 / 8

Methane

1

Ethanol 95% 25 / 7.5

Ammonia

(2)

Paper 16 / 5

(2)

Silane

(1) 30 in. (0.75 m) high, 10 in. (0.25 m) wide plume fire
(2) 20 in. (0.5 m) high, 8 in. (0.2 m) wide plume fire

43 / 13

37 / 11

26 / 8

20 / 6

6 / 1.8

1.5.2 Cone of vision

• Horizontal: 100 °

Horizontal Field of ViewFigure 1-1:

10 Rosemount 975UF

• Vertical: +50 ° (down), -40 ° (up)

Vertical Field of ViewFigure 1-2:

Introduction

Reference Manual 11

Introduction

1.5.3 False alarms prevention

To prevent false alarms, the detector will not alarm or react to the radiation sources
specified in the table below.

Immunity to False Alarm SourcesTable 1-4:

Radiation source Immunity distance ft. (m)

Indirect or reflected sunlight IAD

Vehicle headlights (low beam) conforming to
MS53023-1

Incandescent frosted glass light, 300 W IAD

Fluorescent light with white enamel reflector,
standard office or shop, 70 W (or two 35 W)

Electric arc [15/32 in. (12 mm) gap at 4,000 Vac,
60 Hz]

Arc welding [5/16 in. (6 mm) rod; 210 A] 9.8 (3)

Ambient light extremes (darkness to bright light
with snow, water, rain, desert glare, and fog)

Bright colored clothing, including red and safety
orange

Electronic flash (180 W-seconds minimum out­put)

Movie light, 625 W quartz DWY lamp (Sylvania
S.G. - 55 or equivalent)

Blue-green dome light conforming to
M251073-1

Flashlight (MX 99 I/U) IAD

Radiation heater, 3,000 W IAD

Radiation heater, 1,000 W with fan IAD

Quartz lamp (1,000 W) 12 (4)

Mercury vapor lamp IAD

Grinding metal 3.3 (1)

Lit cigar IAD

Lit cigarette IAD

Match, wood, stick, including flare up 3.3 (1)

IAD

IAD

IAD

IAD

IAD

IAD

> 6.5 (2)

IAD

1. IAD: Immune at any distance.

2. All sources are chopped from 0 to 20 Hz.

12 Rosemount 975UF

1.5.4 Visual indicators

One three-color LED indicator is located inside the detector window, as shown in

Figure 1-3. The detector statuses are listed in Table 1-5.

LED IndicationsTable 1-5:

Detector status LED color LED mode

Fault, BIT Fault Yellow 4 Hz - flashing

Normal Green 1 Hz - flashing

Warning Red 2 Hz -flashing

Alarm Red Steady

Indication LEDFigure 1-3:

Introduction

A. Indicator LED

1.5.5

Reference Manual 13

Output signals

Outputs are available according to the default configuration or the wiring options selected
for the detector.

Introduction

Determine the outputs of your model according to Table 1-6.

The detector incorporates several types of output suitable to different control systems.

• 0-20 mA (stepped) with HART

• Relays (alarm, fault, auxiliary)

• RS-485 Modbus

• Analog output - analog output proved ultra-fast detection to comply with twenty

millisecond detection

Available Output TypesTable 1-6:

Output type Version Detector status

Alarm relay 975UF- output configurations

1AXXXXX, 1RXXXXX, and
2RXXXXX

975UF - output configurations
2AXXXXX and 3AXXXXX

Auxiliary relay 975UF - output configurations

1AXXXXX, 2AXXXXX, and
1RXXXXX

Fault relay 975UF - output configurations

1AXXXXX, 2AXXXXX, and
1RXXXXX

975UF - output configurations
3AXXXXX and 2RXXXXX

0-20 mA current output 975UF - output configuration

1AXXXXX

975UF - output configurations
2AXXXXX and 3AXXXXX

RS-485 All versions Modbus protocol

Analog output All versions 0 V during normal

The relay is N.O.

The relay is N.O. and N.C.

The relay is N.O.

The relay is N.C. energized.

The relay is N.O. energized.

Sink with the HART protocol
(can be changed to Source - see

Figure B-3, Figure B-4, and
Figure B-5).

Source with the HART protocol

5 V during detection

1.5.6 Detector status

The possible detector function statuses are listed in the table below. A more detailed fault
analysis can be seen via HART or RS-485.

Detector StatusesTable 1-7:

Status Description

Normal Normal operation.

14 Rosemount 975UF

Introduction

Detector Statuses (continued)Table 1-7:

Status Description

BIT Built-in test being performed.

Warning Fire detected - changed to Warning (pre-alarm state).

Alarm Fire detected - changed to Fire Alarm state.

Latched alarm (optional) The alarm outputs remain latched on following detection of a fire

that has already been extinguished.

BIT fault A fault is detected during built-in test sequence or other electric fail-

ure. The detector will continue to detect for fire.

Fault A fault is detected when the power supply is too low or due to a soft-

ware fault or electrical failure. The detector will not detect fire in this
condition.

In each state, the detector activates different outputs, as specified in Table 1-8.

Output Signals vs. Detector StateTable 1-8:

Detector state LED indicator LED mode Alarm relay Auxiliary relay Fault relay mA output

Normal Green 1 Hz Off Off On 4 mA

On

(1)

(1)

(1)

On 16 mA

On 20 mA

Off 16 mA

Warning Red 2 Hz Off On

(2)

Alarm

(3)

Latch

BIT Fault

(4)

Warning at BIT

Red Constant On On On 20 mA

Red Constant On Off On 20 mA

Yellow 4 Hz Off Off Off 2 mA

Red 2 Hz Off On

Fault

Alarm at BIT

Red Constant On On Off 20 mA

Fault

Fault Yellow 4 Hz Off Off Off 0 mA

(1) The auxiliary relay can be activated at the Warning level or Alarm level, depending on programmed function.
(2) The alarm outputs are activated while alarm conditions exist and will stop approximately five seconds after a fire is no longer detected.

(3) The Alarm state can be optionally latched via programmed function. (Default is non-latching).
(4) The detector will remain in BIT Fault state until it has passed a successful built-in test.

Note

The outputs depend on the output configurations.

Optional latching

Alarms are set as non-latching by default. However, the detector includes a latched alarm
output capability, which operates according to the programmed function.

Reference Manual 15