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•

Heated continuously

•

Start heating below 41 °F (5 °C)

3.4.3

Setting up detector defaults

The detector has three functions which can be programmed according to the customer
requirements at the factory or at the customer facility using a software host or a field
communicator, available for download from 

Emerson.com

.

Please contact Emerson for more information.

The standard setup is as follows:

Table 3-4: Detector defaults

Function

Default

Gas type

Methane

Heat mode

Auto

Heat on

41 °F (5 °C)

You can change the source defaults the same way.

Table 3-5: Source defaults

Function

Default

Heat mode

Auto

Heat on

41 °F (5 °C)

Reference Manual 

Operating modes

00809-0100-4035

May 2022

Rosemount 935

21

Summary of Contents for Rosemount 935

Page 1: ...Reference Manual 00809 0100 4035 Rev AH May 2022 Rosemount 935 Open Path Combustible Gas Detector ...

Page 2: ...ical security is an important part of any security program and fundamental to protecting your system Restrict physical access by unauthorized personnel to protect end users assets This is true for all systems used within the facility NOTICE The source and detector are not field repairable due to the meticulous alignment and calibration of the sensors and the respective circuits Do not attempt to m...

Page 3: ...d IR3 Refers to the three infrared sensors JP5 Jet fuel Latching Refers to relays remaining in the On state even after the On condition has been removed LED Light emitting diode LEL Lower explosive limit The minimum concentration of a substance gas vapor in air mixture that can be ignited This mixture is different for every gas vapor measured in of LEL LEL m Integral of concentration in LEL units ...

Page 4: ...Abbreviation Meaning RTSP Real time streaming protocol SIL Safety integrity level UNC Unified coarse thread Vac Volts alternating current Vdc Volts direct current µm Micrometer 4 ...

Page 5: ...ructions 27 4 5 Special conditions for safe use from ATEX IECEx certificate 28 4 6 Installing conduits and cables 29 4 7 Mount detector and source to tilt mount 30 4 8 Wire detector 33 4 9 Wiring to detector terminals 34 4 10 Flash source wiring 35 4 11 Align detector 36 Chapter 5 Operation 39 5 1 Open path system operation 39 5 2 Power up 39 5 3 Safety precautions 40 5 4 Verify signal 40 5 5 Zero...

Page 6: ...Transmitter 53 A 5 Detector Receiver 54 Appendix B Specifications 57 B 1 General specifications 57 B 2 Electrical specifications 57 B 3 Mechanical specifications 59 B 4 Environmental specifications 60 Appendix C Product certifications 63 C 1 ATEX and IECEx 63 C 2 UK CA 63 C 3 FM FMC 63 C 4 SIL 2 63 C 5 Functional approval 64 Appendix D Wiring configurations 65 D 1 RS 485 communication network 69 A...

Page 7: ...rees of misalignment The detector is manufactured with heated optical windows to improve performance in icing snow and condensation conditions The programmable functions are available through a HART port used with an intrinsically safe I S handled unit The source and detector unit enclosures are ATEX IECEx and UK CA approved Exd flameproof with an integral segregated rear and an Exe terminal compa...

Page 8: ...Product overview Reference Manual May 2022 00809 0100 4035 8 Emerson com Rosemount ...

Page 9: ...tocol RS 485 output Modbus compatible for personal computer PC communication network for a maximum of 247 systems Simple one person installation alignment and calibration ATEX IECEx and UK CA per Ex II 2 2 G D Ex db eb ib ib Gb IIB H2 T4 Gb Ex tb ib Db IIIC T135 C Db Ta 55 C to 65 C TUV approved per SIL2 requirements FM FMC approved per Class I Div 1 Group B C and D Class II III Div 1 Group E F an...

Page 10: ...int Each hazardous material is detected at a specific wavelength selected according to its specific spectral absorption or fingerprint The detection process involves two separate sensors one that absorbs a particular gas and one that is not sensitive to it 2 3 2 Optical path The presence of hazardous airborne vapors gases or aerosols in a monitored area is detected when the defined substance cross...

Page 11: ...e of methane and propane is 5 LEL m The full scale of ethylene is 8 LEL m 2 3 6 Flash source The Rosemount 935 transmitter employs the latest generation of Xenon flash bulbs to provide extended installation distance and maximum reliability 2 3 7 Heated optics The Rosemount 935 includes heated optics for the detector and source The heater increases the temperature of the optical surface by 5 to 8 F...

Page 12: ...h and status You can connect the HART communication on the 0 20 mA line or through the intrinsically safe I S connection with a standard field communicator loaded with our device driver DD software and a special harness 2 3 9 Modbus RS 485 For more advanced communications the Rosemount 935 has an RS 485 Modbus compatible output that provides data communication This feature enables simple commissio...

Page 13: ... T4 265 ft 81 m 660 ft 201 m 2 5 Description The Rosemount 935 comprises two main units Flash infrared source Detector This device detects gases over an open path transmitted from the source to the detector 2 5 1 Flash source unit The flash source unit emits infrared IR radiation pulses at the rate of two pulses per second The pulse width 5 10 µsec is very powerful The front of the source has a le...

Page 14: ...g to digital signal converter to be processed by the internal microprocessor When the signals drop below a prescribed level the internal microprocessor compensates for them This allows the signals to be maintained even in severe weather conditions The data is sent to the output interface section The front window of the detector is heated to improve performance in icing condensation and snow condit...

Page 15: ...ion C Weather shield D Front window section E Label F Main housing G Mounting plate H Junction box I Back cover J Indicator light emitting diode LED K Earth terminal L Cable inlet Reference Manual Technical description 00809 0100 4035 May 2022 Rosemount 935 15 ...

Page 16: ...Technical description Reference Manual May 2022 00809 0100 4035 16 Emerson com Rosemount ...

Page 17: ... scale reading View warning and alarm states through the LED RS 485 and HART If using the RS 485 output the detector changes its status from N to W at Warning level and to A at Alarm level 3 1 2 Maintenance call mode 3 mA output This mode indicates low signal that may be caused by a dirty window misalignment or poor source or if one of the detector s parameters is at the limit value The device con...

Page 18: ...el from which the detector reads gas Only do this when No gases are present There is a clear path between the source and the detector Weather conditions are clear Use a field communicator or host software on your personal computer PC to zero calibrate after installation re alignment and window cleaning While the device is connected to the field communicator you can also use the magnetic mode selec...

Page 19: ...atus and description 0 mA 0 2 mA Fault in 0 20 mA loop 1 mA 0 2 mA Zero calibration in progress fault 2 2 mA 0 2 mA Fault 1 non critical 2 5 mA 0 2 mA Misalignment fault 3 mA 0 2 mA Maintenance call 4 mA 0 2 mA No gas present 4 mA 20 mA Continuous measuring of gas concentrations at a range between 0 and full scale For methane and propane this translates to 3 2 mA per LEL m and for ethylene to 2 mA...

Page 20: ...sitivity Please consult Emerson for information on how to detect other gases Setting up addresses The detector provides up to 247 address that can be used in the RS 485 communication link and up to 64 addresses that can be used in the HART Field Communication link Setting up heated optics Select one of the following mode s for the detector s heated optics Off Not operated On Operated continuously ...

Page 21: ...re host or a field communicator available for download from Emerson com Please contact Emerson for more information The standard setup is as follows Table 3 4 Detector defaults Function Default Gas type Methane Heat mode Auto Heat on 41 F 5 C You can change the source defaults the same way Table 3 5 Source defaults Function Default Heat mode Auto Heat on 41 F 5 C Reference Manual Operating modes 0...

Page 22: ...Operating modes Reference Manual May 2022 00809 0100 4035 22 Emerson com Rosemount ...

Page 23: ... 1 Required tools Install the device using the following general purpose common tools and equipment Table 4 1 Tools Tool Function Alignment kit Provides tools to install fine alignment tool Hex key 8 mm Mounts the detector on the tilt mount Hex key 3 16 in Aligns the detector Hex key 5 16 in Screws stop plug Flat screwdriver 4 mm Connects ground terminal Flat screwdriver 2 5 mm Connects wires to t...

Page 24: ... this distance to 50 percent Keep the open path between the source and detector clear of any obstacles that might hinder the free movement of air in the protected area or block the infrared beam 4 2 4 Tips for gas detector locations To provide the best detection coverage install the detector Below potential leak source for gases heavier than air Above potential leak sources for gases lighter than ...

Page 25: ...20 m 33 ft 10 m 427 ft 130 m 34 5 ft 10 5 m 459 ft 140 m 38 ft 11 5 m 492 ft 150 m 42 5 ft 13 m 525 ft 160 m 47 5 ft 14 5 m 558 ft 170 m 49 ft 15 m 591 ft 180 m 51 ft 15 5 m 693 ft 211 m 52 5 ft 16 m 656 ft 200 m 54 ft 16 5 m 4 2 6 Wiring For wiring use color coded conductors or suitable wire markings or labels The wire cross section must be between 28 to 14 American Wire Gauge AWG 0 5 mm2 to 2 5 ...

Page 26: ...he following in addition to the Quick Start Guide Figure 4 1 Box cContents Commissioning kit not pictured A Source or detector per box B Tilt mounts Detector unit 935 R1F00XXXX see Table 2 1 Source unit 935 TXFXXXXXX see Table 2 1 Two tilt mount bases one for the source and one for the detector 1 Commissioning kit three options when ordered For methane calibration For propane calibration For ethyl...

Page 27: ...he event that the installation is not completed in a single session secure and seal detectors and conduits 4 4 Certification instructions WARNING EXPLOSION Do not open the detector even when isolated in a flammable atmosphere The cable entry point may exceed 182 F 83 C Take suitable precautions when selecting the cable The equipment may be used with flammable gases and vapors with apparatus groups...

Page 28: ...for IIB H2 as detailed in Table 4 3 Table 4 3 Flamepaths Flamepath description Type of joint Minimum width L Maximum gap ic Cylindrical section of spigot both ends of Ex d compartment Cylindrical 0 59 in 15 mm 0 003 in 0 1 mm 1 2 in 30 mm diameter window fitted against enclosure Flanged 0 42 in 11 mm 0 001 in 0 03 mm 1 6 in 39 5 mm diameter window fitted against enclosure Flanged 0 39 in 10 mm 0 0...

Page 29: ...densation in the detector install it with the conduits cable entries facing downwards Use flexible conduits cables for the last portion connecting to the detector When pulling the cables through the conduits ensure that they are not tangled or stressed Extend the cables about 12 in 305 mm beyond the detector location to accommodate wiring after installation After pulling the conductor cables throu...

Page 30: ...me tilt mount by using the upper or lower mounting access Figure 4 2 Mounting the tilt mount and detector using the lower mounting access A Front shield B Back cover C Security screw D Locating pins E Alternate mounting location Installation Reference Manual May 2022 00809 0100 4035 30 Emerson com Rosemount ...

Page 31: ...t holding plate D Horizontal fine alignment screw E Vertical crude alignment tightening screw F Vertical fine alignment tightening screw G Horizontal crude alignment tightening screw H Horizontal fine alignment tightening screw Reference Manual Installation 00809 0100 4035 May 2022 Rosemount 935 31 ...

Page 32: ...uisites Prior to mounting the tilt mount to a stable surface verify that the line of site is unobstructed and corresponds to the detector s installation distance Procedure 1 Place the tilt mount holding plate in its designated location and secure it with four fasteners through four holes with diameters of NaN in NaN mm NOTICE Skip this step if the tilt mount is already installed Installation Refer...

Page 33: ... x 1 5 screws 5 Repeat steps Step 1 through Step 4 to install the source 4 8 Wire detector Figure 4 5 Detector with cover removed A Housing B Internal earth connection C Terminal board D Inlet conduit E Detector holding plate F Earth terminal G Connection to field communicator Procedure 1 Release the back cover secure bolt and open the detector back cover 2 Remove the protective plug mounted on th...

Page 34: ...ded to earth ground 7 Place and secure the detector cover by screwing the cover and securing it using the secure bolt Related information Wiring configurations 4 9 Wiring to detector terminals The detector has six wiring terminals Table 4 5 describes the function of each electrical terminal of the detector Table 4 5 Wiring terminals Terminal number Function 1 Power 24 Vdc 2 Return 24 Vdc 3 0 20 mA...

Page 35: ...e conduit cable entry inlet pull the wires through the source inlet 3 Use a in 14 national pipe thread NPT or M25 x 1 5 explosion proof conduit connection cable gland to assemble the cable explosion proof conduit to the detector 4 Connect the wires to the required terminals according to the wiring diagram See Wiring to source terminals and Wiring configurations 5 Connect the grounding wire to the ...

Page 36: ... rear access is possible you don t need to install the periscope In this case you can remove it by releasing the periscope fastening screw NOTICE Prior to installing the alignment tool verify that the alignment tool and its sight mounting are free from any dirt to ensure proper alignment according to factory calibration Do not attempt to change any factory calibration at the alignment tool or its ...

Page 37: ...tor with the alignment tool installed Procedure 1 Remove the front shield and mount the alignment tool on the front of the source using the three screws The alignment tool is supplied in the commissioning kit 2 Aim the source towards the detector within the horizontal access 3 Aim the alignment tool to the center of the front window of the detector or source Figure 4 7 View through the alignment t...

Page 38: ...Postrequisites Once you have completed fine alignment for both the source and detector you can turn on the power Installation Reference Manual May 2022 00809 0100 4035 38 Emerson com Rosemount ...

Page 39: ...individuals who have or will have responsibility for using maintaining or servicing this product must read this manual thoroughly NOTICE Disconnect external devices such as fire alarms and automatic extinguishing systems before performing maintenance Procedure 1 Ensure that the source and detector are connected to power 2 Ensure that the 4 20 mA wiring meter is connected to the detector 3 Power up...

Page 40: ...horoughly NOTICE Disconnect external devices such as fire alarms and automatic extinguishing systems before performing maintenance 5 4 Verify signal Use an RS 485 or HART Field Communicator to verify the signal in accordance with Table 5 1 Figure 5 1 Light Emitting Diode LED Indication Before Zero Calibration 1 Verify LED indication 2 Use Winhost or HART to verify installation parameters Operation...

Page 41: ... explosive limit LEL 0 LEL x m Temperature Up to 25 C beyond ambient temperature Voltage 32 Vdc V 18 Vdc Note The installation information refers to the installation distance Minimum The minimum distance as defined according to the model number Medium Half the maximum distance as defined according to the model number Maximum The maximum distance as defined according to the model number Reference M...

Page 42: ...ge E Reference minimum F Signal minimum G Ratio H NQ ratio I LEL 5 5 Zero calibrate Prerequisites Zero calibrate after any of the following Installation Realignment Window cleaning Any change in detector or source position Operation Reference Manual May 2022 00809 0100 4035 42 Emerson com Rosemount ...

Page 43: ... is a clear path between the source and the detector Weather conditions are clear Before zero calibrating align the detector precisely Figure 5 3 Screens shown when zero calibrating with WinHost software Reference Manual Operation 00809 0100 4035 May 2022 Rosemount 935 43 ...

Page 44: ... from Alignment to Standby mode 3 Switch from Standby to Zero Calibration mode The 0 20 mA output should now be at 1 mA 4 Wait up to sixty seconds until it switches to Normal mode The detector reading is now set to Normal The 0 20 mA output should now indicate 4 mA Postrequisites Once zero calibration is complete refer to Signal limitation values to verify the installation parameters Operation Ref...

Page 45: ... the power to the detector is on and that the current of the 0 20 mA channel is stable Record the reading Procedure 1 Position the functional check filter in front of the detector Center the functional check filter s window over the viewing window of the detector The check filters are provided in the commissioning kit Figure 5 5 Detector with functional check filter installed 2 Wait twenty seconds...

Page 46: ...Operation Reference Manual May 2022 00809 0100 4035 46 Emerson com Rosemount ...

Page 47: ...ates the current signals from the flash source compared to that of previous alignments We recommend performing this check every six to twelve months Check the signal according to threshold levels Zero calibrate every time the detector or source is realigned or the windows are cleaned 6 2 1 Clean viewing windows Procedure 1 Turn off the power to the detector and source 2 In places where dust or dir...

Page 48: ...10 Do a functional check Maintenance Reference Manual May 2022 00809 0100 4035 48 Emerson com Rosemount ...

Page 49: ...Light emitting diode LED yellow blinking Table 7 2 Potential Causes and Resolutions Potential cause Resolution Poor alignment Align Dirt on the window Clean the window Poor light source Replace the light source Detector fault Replace or repair the detector 7 3 Detector is in constant Saturation mode Host status S 0 20 2 mA Light emitting diode LED yellow blinking Table 7 3 Potential Causes and Res...

Page 50: ...1 mA Light emitting diode LED yellow blinking Table 7 5 Potential Causes and Resolutions Potential cause Resolution Low high input voltage Check the power supply and installation Detector fault Replace or repair the detector 7 6 Internal fault Host status F 0 20 1 mA Light emitting diode LED yellow blinking Table 7 6 Potential Cause and Resolution Potential cause Resolution Internal fault Replace ...

Page 51: ...Resolution Poor alignment Align 7 9 Ratio out of the limit Host status F 0 20 1 mA LED yellow blinking Table 7 9 Potential causes and resolutions Potential cause Resolution Poor alignment Align Dirt on the window Clean the window Detector fault Replace or repair the detector 7 10 Source fault Yellow light emitting diode LED blinking at the source Table 7 10 Potential Causes and Resolutions Potenti...

Page 52: ...Troubleshooting Reference Manual May 2022 00809 0100 4035 52 Emerson com Rosemount ...

Page 53: ... related to each product Exact model codes will vary examples of typical model codes are shown in Source Transmitter and Detector Receiver Source Transmitter 935T1F002SA1 Detector Receiver 935R1F012SA1 A 3 Specifications and options See Specification for more details on each configuration Specification and selection of product materials options or components must be made by the purchaser of the eq...

Page 54: ...tion F00 Transmitter Housing style conduit Code Material Measurement 2S Stainless steel in NPT 4S Stainless steel M25 Product certifications Code Description A1 ATEX and IECEx A2 FM E2 INMETRO EM CU TR EAC A 5 Detector Receiver A 5 1 Required model components Model Code Description 935 Combustible Open Path Gas Detector Receiver Receiver selection Code Description R1 Receiver Ordering information ...

Page 55: ...ale 5 LEL m default Housing style conduit Code Material Measurement 2S Stainless steel in NPT 4S Stainless steel M25 Product certifications Code Description A1 ATEX and IECEx A2 FM E2 INMETRO EM CU TR EAC Reference Manual Ordering information 00809 0100 4035 May 2022 Rosemount 935 55 ...

Page 56: ...Ordering information Reference Manual May 2022 00809 0100 4035 56 Emerson com Rosemount ...

Page 57: ...c to T90 Spectral response 2 0 3 0 micron Sensitivity range Full scale LEL m Warning LEL m Alarm LEL m Gas 1 Methane 5 1 3 Gas 2 Propane 5 1 3 Gas 3 Ethylene 8 1 6 4 8 Field of view Line of sight Alignment tolerance 0 5 Drift 7 5 of the reading or 4 of the full scale whichever is greater Minimum detectable gas volume 0 15 LEL m Temperature range 67 F 55 C to 149 F 65 C Immunity to false alarm Does...

Page 58: ...ompatible with the Modbus protocol This protocol is standard and widely used It enables continuous communication between a single standard Modbus controller master device and a serial network of up to 247 detectors It enables connection between different types of Rosemount detectors or other Modbus devices to the same network HART protocol A digital communication protocol used to communicate betwe...

Page 59: ...x tb ib Db IIIC T135 C Db Water and dust tight IP66 and IP68 NEMA 250 Type 6p Electrical modules Conformal coated Electrical connection Two options specified at time of order 2 x M25 for International Organization on Standardization ISO 2 x in 14 NPT conduits Dimensions Detector 10 5 in 267 mm x 5 1 in 130 mm x 5 1 in 130 mm Source 10 5 in 267 mm x 5 1 in 130 mm x 5 1 in 130 mm Tilt mount 4 7 in 1...

Page 60: ...NVGL CG 0339 class B Enclosure The Rosemount 935 system conforms to DNVGL CG 0339 class C Water and dust IP68 per EN60529 IP66 per EN60529 Dust Completely protected against dust Liquids Protected against immersion between 5 9 in 15 cm and 3 3 ft 1 m in depth Protected against water jets from all directions Vibration The Rosemount 935 system conforms to DNVGL CG 0339 class B Electromagnetic compati...

Page 61: ...protect against interference caused by radio frequency interference RFI and electromagnetic interference EMI the cable to the detector must be shielded and the detector must be grounded Ground the shield at the detector end Reference Manual Specifications 00809 0100 4035 May 2022 Rosemount 935 61 ...

Page 62: ...Specifications Reference Manual May 2022 00809 0100 4035 62 Emerson com Rosemount ...

Page 63: ...175X Ex II 2 2 G D Ex db eb ib ib Gb IIB H2 T4 Gb Ex tb ib Db IIIC T135 C Db Ta 55 C to 65 C C 3 FM FMC The Rosemount 935 is approved to FM FMC explosion proof per Class I Div 1 Group B C and D T6 50 C Ta 65 C Dust ignition proof Class II III Div 1 Group E F and G Ingress protection IP66 IP68 NEMA 250 Type 6P C 4 SIL 2 The Rosemount 935 is TUV approved for SIL 2 requirements per IEC61508 The alert...

Page 64: ... SIL 2 Features and TUV report number 968 EZ619 00 13 C 5 Functional approval The Rosemount 935 was functionally approved per FM6325 The Rosemount 935 was functionally tested by FM per EN60079 29 4 Product certifications Reference Manual May 2022 00809 0100 4035 64 Emerson com Rosemount ...

Page 65: ...gurations Figure D 1 Detector Wiring Terminal A Power 18 to 32 Vdc B Return C 0 20 mA input D 0 20 mA output E RS 485 F RS 485 G Ground Reference Manual Wiring configurations 00809 0100 4035 May 2022 Rosemount 935 65 ...

Page 66: ...Figure D 2 Source Wiring Terminal A Power 18 to 32 Vdc B Return C Not used D RS 485 E RS 485 F Ground Wiring configurations Reference Manual May 2022 00809 0100 4035 66 Emerson com Rosemount ...

Page 67: ...Figure D 3 0 20 mA Sink 4 Wire A Detector B Controller C Input power 18 32 Vdc D Return E 0 20 mA meter Reference Manual Wiring configurations 00809 0100 4035 May 2022 Rosemount 935 67 ...

Page 68: ...B Controller C Input power 18 32 Vdc D Return E 0 20 mA meter Figure D 5 0 20 mA Source 3 Wire A Detector B Controller C Input power 18 32 Vdc D Return E 0 20 mA meter Wiring configurations Reference Manual May 2022 00809 0100 4035 68 Emerson com Rosemount ...

Page 69: ... repeaters the number of detectors can be much larger 32 detectors for each repeater up to 247 on the same four wires When using the RS 485 network it is possible to read the detector status Fault Warning and Alarm For more details consult Emerson Figure D 6 RS 485 Networking for Wiring Option 3 A Controller B First detector C Last detector D Power supply E RS 485 computer port Reference Manual Wi...

Page 70: ...Wiring configurations Reference Manual May 2022 00809 0100 4035 70 Emerson com Rosemount ...

Page 71: ...PFH _SIL2 11 5 E 2 General conditions for safe use The Rosemount 935 should consist only of the approved hardware and software models Consider the application advice and limitations of the Manual For calibration and maintenance consider the regional and national regulations The 24 V power supply must fulfill the requirements for PELV SELV of EN 60950 The HART and RS 485 interfaces are not allowed ...

Page 72: ...s calibration checks The operator must switch the Rosemount 935 OFF and ON The connected controller must monitor the 0 20 mA signal current for values below 4 mA and above 20 mA The mean time to repair should be 72 hours SIL 2 features Reference Manual May 2022 00809 0100 4035 72 Emerson com Rosemount ...

Page 73: ...lude the following information when returning equipment a RMA number Emerson provided to you b Company name and contact information c Purchase order from your company authorizing return 2 Pack all items to protect them from damage and use anti static bags or aluminum backed cardboard as protection from electrostatic damage 3 Mark all packages with Return and include the RMA number 4 Ship all equip...

Page 74: ...Support Reference Manual May 2022 00809 0100 4035 74 Emerson com Rosemount ...

Page 75: ...G Declaration of Conformity Reference Manual Declaration of Conformity 00809 0100 4035 May 2022 Rosemount 935 75 ...

Page 76: ...Emerson All rights reserved Emerson Terms and Conditions of Sale are available upon request The Emerson logo is a trademark and service mark of Emerson Electric Co Rosemount is a mark of one of the Emerson family of companies All other marks are the property of their respective owners ...

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