User Manual - Rohrback Cosasco Systems
Contents
1. 25 T Table of Contents SEIL 4020LT A Corrosometer Transmitter Figures and Drawings Figure Page 1 1 402011 48 Transmitter Unit 1 1 2 System Configuration Options 2 1 9 Instrument Type Probe Type Compatibility 3 3 1 Types of Cable Connectors and Probes 7 3 2 10101111130 DIMENSIONS NETT veneers OT 8 OEC Wiring Configurations with Safety Barriers 9 4 1 CORROSOMETER Probe Types and Spans 15 iv Table of Contents 4020LT A Corrosometer Transmitter 1 Introduction CHAPTER 1 The Model 40201 transmitter is a two wire transmitter for use with Corrosometer probes This transmitter is well suited for plant locations widely separated monitoring points and connection into a distributed control system DCS Note that the DCS must be able to graph data against time and compute metal loss corrosion rates from supplied algorithms Figure 1 1 4020LT A Transmitter Unit 2 Introduction The Model 4020LT A is easily field mounted and readily applied to the measurement of corrosivity in most process applications Most wire loop tube strip or all welded CORROSOMETER probes may be used with the Model 4020LT A Transmitter WARNING The Model 4020LT A transmitter is not suitable for use with CORROTEMP CORROSOMET2. all vii 540025 INOZ HO 2 G3ISISSVIONN SNOGHYVZVH NON 1 Q3l4ISSV10 SNOGYVZVH 28 Requirements for Intrinsic Safety Operation Certificate of Compliance Certificate 70026847 Master Contract 252060 Project 70026942 Date Issued 2015 04 27 Issued to Rohrback Cosasco Systems Inc 11841 Smith venue Santa Fe Springs California 90670 USA Attention Lucky Iliev The products listed below are eligible to bear the CSA Mark shown with adjacent indicators and US for Canada and 05 or with adjacent indicator US for US only or without either indicator for Canada only d Issued by INO IS Us David Holton C PRODUCTS CLASS 2258 04 PROCESS CONTROL EQUIPMENT Intrinsically Safe Entity For Hazardous Locations Ex ib T4 Gb CLASS 2258 84 PROCESS CONTROL EQUIPMENT Intrinsically Safe Entity For Hazardous Locations CERTIFIED 0 5 STANDARDS AEx ib T4 Gb Model 4020LT A Comosometer Transmitter intrinsically sate with input entity parameters Ui 30V 11 125m Pi 0 84W Li 0 output entity parameters 5 355V 10 0 8224 0 213W Ci 250nF 64uF Li 40uH La 12 6 pH 409 lt 8000 For details related to rating size configuration etc reference should be made to the CS A Certification Record or the descriptive report 20D 507 Rev 2012 05 22 4020LT A Corr
3. ER 1 510 T10 5 mil 5878 4 mil NE 845 S4 58 T4 0 1 lee LL N 4 1 mil TF50 2500 A 0 01 mil Response Time Hours Based on 195 Probe Life or 10 Divisions Figure 2 4020LT A Corrosometer Transmitter 21 Corrosion Probe Span mils 73 days 5months 6 months 12 months 24 months 30 months 0 1 37 days 18 days 4 days 2 days 18 hours 9 hours 6 hours 4hours 5hours Table 1 Corrosion Early Trend Meaningful End of Useful Rate Indication Rate Data Probe Life with 10 4 Div 10 Div 1000 Div Span Probe 1 6 hour 4 0 hour 17 days 220 mpy 5 6 mm y 4 0 hour 10 0 hour 1 4 months 88 mpy EM 1 3 3 months 37 0 94 mm y 1 8 days 6 0 months 20 mpy 0 51 mm y 2 7 days 9 0 months 13 mpy 0 33 mm y 3 days 12 0 months 10 mpy 0 25 mm y 4 6 days 15 0 months 8 mpy 0 20 mm y 5 5 days 18 0 months 6 7 mpy 0 17 mm y 2 9 days 7 3 days 24 0 months 5 mpy 0 13 mm y All data shown to two significant digits only Table 2 22 Theory From Table 1 it would appear desirable to always choose probes with the lowest span available in order to get the greatest sensitivity However the more sensitive the probe the faster the entire probe span will corrode away and require a new probe to be installed Table 2 illustrates this relationship It is our experience
4. ROHRBACK COSASCO SYSTEMS 4020LT A CORROSOMETER TRANSMITTER User Manual Rohrback Cosasco Systems Inc 11841 Smith Avenue Santa Fe Springs 90670 Tel 562 949 0123 800 635 6898 562 949 3065 P N 741099rev WWW COSasco com 2015 Rohrback Cosasco Systems Inc All rights reserved CORROSOMETER CORRATER CORROTEMP are registered trade marks of Rohrback Cosasco Systems Inc No part of this manual may be reproduced or transmitted in any form or by any means electronic or mechanical including photocopying and recording for any purpose without the express written permission of Rohrback Cosasco Systems Inc 4020LT A Corrosometer Transmitter Table of Contents Chapter 1 Introduction ee Chapter 2 Secllicaliori 1 2 2 TED TURO Chapter 3 Installation 2 2 2 ers 7 ie 7 Mechanical Mounting of Transmitter pp 8 Electrical Wiring of Transmitter sss 9 Chapter 4 Operation UM UN GENESIS Metal Loss From 4 20 mA Signal 11 Corrosion Rate Calculation pp 11 0 ae 15 Chapter 5 Maintenance ADDOLODE RAR CORROSOMETER Theory 4 19 6 2 E E A A E Requirements for Intrinsic Safety Operation
5. 4020LT A Corrosometer Transmitter 17 Maintenance CHAPTER 5 The Model 4020LT A Transmitter should require little maintenance Normal probe replacement is required in order to maintain continuous corrosion monitoring at a site All probes have a certain life based on their geometry and amount of corrosion they are exposed to A probe replacement schedule should be established with a criterion such as 7 8 of probe life 875 span divisions to time change out As a reminder proper probe selection should be based on closely matching probe span to mpy corrosion rate for optimum instrument accuracy During probe replacement all connections such as the connectors at the probe should be environmentally protected and checked for good electrical conduction Under normal conditions the Transmitter should not require recalibration when replacing identical probes It is recommended as a good procedure that the current loop power source be powered down during probe change out WARNING For reasons of maintaining the intrinsic safety certifications it is important that any repairs be carried out by RCS or its authorized agent to maintain the certification of the instrument The Model 4021L Receiver requires no maintenance If a problem is suspected with the probe or transmitter use the test probe provided with the transmitter to test the loop The test probe is marked with the loop current in mA that this should provide in the 4 20 mA loop This sig
6. formula in the Metal Loss from 4 20 mA signal section and x is in units of days from some nominal origin Using a time base of days of data for calculation of rate x 24 x 12 864 data points the corrosion rate from equations 1 and 2 would be in units of mils day This could normally be converted to mils year by multiplying by 365 In setting up the algorithm the time period of 3 days in the example should be adjustable from 1 to 5 days to provide filtering as necessary to minimize noise yet give adequate sensitivity to upsets The shorter the time period the more sensitive but noisier will be the rate calculation The longer the time period the less sensitive but quieter will be the rate calculation 4020LT A Corrosometer Transmitter Probe Spans The following table indicates the probe spans for the various probe types available CORROSOMETER PROBE ELEMENT TYPE Strip Loop 54 E 0 025 0 Flush Element S4 2 0 0 051 Atmospheric Element 54 Strip Loop 58 Tube Loop 4 Flush Element 58 0 102 Atmospheric Element S8 Tube Loop T8 Flush Element 10 127 Cylindrical Element T10 Flush Element S20 254 Cylindrical Element T20 alte Loop Element W40 WireLoopElementW45 A 11 25 0285 286 Flush Element 540 20 0 0 508 Wire Element W80 Cylindrical Element T50 Element T50 D 250 0635 635 Figure 4 1 CORROSOMETER Probe Types and Spans 15 16 Operation
7. that the objectives of most monitoring programs can be achieved cost efficiently by selecting CORROSOMETER probes which will reach the end of their useful life in 6 9 months at the expected corrosion rate Unlike a monthly coupon replacement program this electrical resistance probe will continuously produce data that verifies that the average corrosion rate over the previous 2 3 days is still at the originally expected design rate If the corrosion rate increases to twice the design rate meaningful data to permit the new rate to be calculated will be available in a day and a half Conversely if the actual corrosion rate is below design a longer period is required before meaningful data are available to calculate the new rate CORROSOMETER probe elements are available in a variety of styles A selection of the available styles is shown in Figure 3 Wire tube and strip loop styles all have a loop of metal exposed to the process The loop protrudes from the end of the probe body through either a hermetic glass seal or a Teflon ceramic Teflon epoxy or epoxy seal packing system Choice of materials is dependent upon stream composition process conditions and performance requirements Cylindrical elements utilize specially made thin wall tubing as the measurement element Cylindrical probes are generally all metal i e there is no other material exposed to the process There are however also some cylindrical probes available which join the prob
8. ER Probes The 4020LT A is attached to the probe using the integral extension cable with a maximum length of 100 feet A single twisted pair cable connects the Transmitter to a standard 4 20mA current loop The Transmitter controls loop current as a function of metal loss beginning at 4mA and ending at 20mA when the CORROSOMETER probe sensing element has been fully corroded NOTE The check element of the CORROSOMETER probe 5 not utilized with Model 4020LT A The general system configuration that may be used are indicated in Figure 1 2 HAZARDOUS AREA SAFE AREA DC Supply 4020LT A Barrier Probe Figure 1 2 System Configuration Options 4020LT A Corrosometer Transmitter 3 The Model 4020LT A is compatible with any Rohrback Cosasco CORROSOMETER probe type but is furnished specifically for each of the three basic probe types from the factory The compatibility is listed in Figure 1 3 It is field convertible from one type to another by selecting a probe type with the rotary switch on the front panel Transmitter Suffix Probe Type Element Type Applicable W W40 W45 W60 W80 5 D 10 20 0 Figure 1 3 Instrument Type Probe Type Compatibility 4020LT A Corrosometer Transmitter Specification CHAPTER 2 Transmitter Model 4020LT A e Enclosure NEMA 4X IP66 or Stainless Steel 316L IP66 Weight 4 Ibs 1 8 Kg e Dimensions 8 00 H x 6 25 W x 4 25 D 203mm x 165mm x 108mm e Probe Cable Length 5ft Standar
9. OD TVWHONEN YO TWWHON NIYLNOO 5 3H LOW TWHE LI LWHL 143059 01330 SION AVN ONY A ddia HO TOON HOWEHHOH a 8 2 HI TIES WEN JHL YddMISNY 3002 3 3 TVNOLLVN JHL 40 t08 3100 Hg Boa JO 3002 LWEASTTSH HUM SONVIRHCEXOY MI 38 LENN SNA FI CE 055 HD 34052 19 3 3 IN 209 OL AOZ LN3IBMV Y3HY ShOUBYZVH NON 9 1 29 x3 dnoag SLNINNHLSNI 196 319W X3 tsnivdvYddv 15 31 0 3130 3 HLIA 57 6 MOLO3NNOO 9 38089 2000 15 538 3 ywog 53130505305 TESTO IASI SHIOBDOE 01171551 ATTWOINVATWS 0 HONS 90151934 Y AG 03011111 38 TWHS MEYE JHL MB O 950 5 99 vL 211 91 99 911 4 3 5 3138 5 DII 90049 303 031411 HOLY OS OINVATVE 100 30 150 ANY 411 5 531300608909 99 Fl 211 9 3 10207 06 11 YEOLO FL MIS 3
10. art of the primary pressure seal and because its designed to corrode CORROSOMETER probes have a reduced resistance to leaking after prolonged exposure Once the measurement element has corroded through the internals of the probe body are exposed to the process fluid Although materials are chosen in part for their strength and lack of permeability it is our experience that process fluids will permeate throughout the probe packing material For this reason quality probes are constructed of corrosion resistant body materials and include a secondary pressure seal often consisting of a hermetic glass sealed connector Other back up seals are utilized in special cases especially where process fluids will attack glass e g hydrofluoric acid service Please contact the factory if you have any questions about the compatibility of probe materials with your application The reference and check elements are protected from the process to which the measurement element is directly exposed Temperature changes in the process will therefore affect the measure element before the reference and check elements Because of the very low resistances involved these changes can significantly affect the metal loss readings CORROSOMETER probes incorporate special design features to minimize the thermal resistance of the materials insulating the reference and check elements from the process It should also be noted that cylindrical probes are inherently better able to
11. bes must be allowed to corrode for a period of time before accurate corrosion rate measurements can be made The actual length of time required depends upon the corrosion rate the higher the rate the shorter the time required and vice versa CORROSOMETER probes are available in a variety of styles and with useful probe life span ranging from 2 25 mils in styles commonly used in process piping systems Instrumentation to measure electrical resistance probes divides the probe span into 1000 divisions A probe with 2 mil span is therefore theoretically capable of measuring thickness changes of 0 002 mils In practice however we recommend that a change in indicated metal loss of 10 divisions be required before the data 1 used to calculate corrosion rate Indications of an upward or downward trend can be obtained with as little as a 4 division change but care must be exercised in interpreting such small changes because other factors e g temperature changes can also be responsible The actual time required to produce meaningful corrosion rate information with common probe spans at different corrosion rates is shown in Figure 2 and summarized in Table 1 10 T E aT 1k E o 100 m 02 5 SEAR RE ERE d OR ss W80 an m i
12. d 1008 Maximum Hazardous Area Certifications USA Canada CSA Canada Ex ib T4 Gb Tamb 40 C to 80 CSA US Class Zone 1 AEx ib T4 Gb 40 C to 80 Europe Sira ATEX Ex ib T4 Gb 40 C to 80 IECEx Sira IEC Ex ib T4 Gb 40 C to 80 C Hazardous Area Certification Notes Requires the use of a galvanically isolated safety barrier if probe or transmitter is in a Class 1 Division 2 area Zone 1 or Zone 2 Complies with all applicable EU Product Directives EMC Directive 9 336 EEC ATEX Complies with all applicable EU Product Directives ATEX Directive 94 9 EC e Supply Voltage Range 10 30 VDC at 20 mA Output 4 20 mA into maximum safe area load of 600 ohms with safety barrier e Resolution 0 1 e Ambient Temperature Range 40 C 40 F to 80 C 176 F 6 Specification 4020LT A Corrosometer Transmitter T Installation CHAPTER 3 Unpacking Check that the package contains the following items e Model 4020LT A Transmitter e Test probe attached to probe cable e Instruction Manual NOTE All 4020LT A system components are carefully tested inspected and packaged prior to shipment Before unpacking the instruments please inspect the packaged materials for shipping damage and retain damaged materials to support any claim against the freight carrier should this become necessary Before Installatio
13. e body at a hermetic glass seal A variety of flush mounted probes are also available so called because the measuring element is mounted parallel to the flow stream flush with the inside pipe wall STRIP LOOP TUBE LOOP WIRE LOOP CYLINDRICAL ATMOSPHERIC FLUSH END VIEW FLUSH END VIEW Figure 3 4020LT A Corrosometer Transmitter 23 EEC CORROSOMETER monitoring systems be applied to all processes However some types of CORROSOMETER probes are better suited to the requirements of particular applications than others Different styles of CORROSOMETER probes are affected to different degrees by pitting attack Figure 4 shows the results of pitting attack on a wire loop probe Although the remaining wire thickness shows that only 30 or so of the probe span has been consumed the probe is obviously out of service Cylindrical elements on the other hand are affected to a much lesser degree by pitting because of the much larger circumference of the measuring element Wire loop and tube loop elements also have a tendency to be electrically shorted by a bridge of iron sulfide corrosion product This is especially prevalent in low velocity streams over an extended period The effect of such bridging is to reduce the measured metal loss of the probe creating a misleadingly low corrosion rate Cylindrical probes demonstrate more resistance to iron sulfide bridging due to their construction and lower inherent resistance per unit length thus mini
14. mizing the effect of the shunt resistance Where pitting or substantial FexSy deposition are expected to be problems cylindrical probes should be chosen wherever possible over loop style probes Figure 4 24 Corrosometer Theory ea E Oo Most cylindrical probes are of all welded construction in order to eliminate the need for sealing metal elements to non metallic glass epoxy or ceramic This all welded construction gives the probe superior resistance to leaking Probes with higher temperature ratings can also be constructed in the all welded style A drawback to the all welded style is that the element is electrically connected to the pipe wall which can in certain conditions interfere with the corrosion reaction on the probe Also because cylindrical probes are welded in some conditions preferential corrosion can occur in the heat affected zones near the weld Flush probe elements are thin flat metal sections embedded in epoxy or a hermetic glass seal inside a metal probe body Flush probes also experience certain characteristic problems most notably lack of adhesion of the metal element to the epoxy cracking of glass seals due to differential expansion and erosion of the epoxy or glass due to high velocities abrasive materials in the flow stream or both Flush CORROSOMETER probes mounted on the bottom of the line have been shown to provide good results in a sour gas gathering system Because the measurement element is p
15. n Installation of the 4020LT A consists of two separate tasks Mechanical mounting Electrical wiring Before proceeding with the installation several items must be considered Make sure the Model 4020LT A has the correct Rohrback Cosasco Systems type probe connector and the correct setting for the probe type selector switch Figure 3 1 Types of Cable Connectors and Probes 8 Installation The transmitter should be mounted close enough to the probe to allow the use of the 60 inch extension cable supplied For mounting of the transmitter or probe in a hazardous area the correct galvanically isolated safety barrier and instructions of the intrinsic safety certification must be followed NOTE Transmitters are available with longer cables up to a maximum of 100 ft Mechanical Mounting of Transmitter The Model 4020LT A Transmitter should be located within 48 inches of the CORROSOMETER probe to be monitored The standard cable is 60 inches long and the extension cable is 1200 inches long but it is preferable to allow a service loop of approximately 12 inches to the probe 6 50 165 31 X 50 SLOT 8 X 13 SLOT 4 PLACES 4 00 102 8 00 6 94 203 176 Vent Drain Figure 3 2 Mounting Dimensions 4020LT A Corrosometer Transmitter 9 Electrical Wiring of Transmitter If both the probe and transmitter are located in a non electrically hazardous area the transmitter may be connected as any other
16. nal may be converted to check the display on the receiver if applicable Test probe mA 4 Metal loss display x Probe SPAN mils 16 18 4020LT A Corrosometer Transmitter 19 CORROSOMETER THEORY APPENDIX A CORROSOMETER Systems are based on the electrical resistance method of corrosion monitoring pioneered by Rohrback in the 1950 s and 1960s CORROSOMETER probes are basically electrical coupons They determine the loss of metal from the by measuring the change in its resistance Because of the very low resistances involved very sensitive monitoring circuits are used in CORROSOMETER instruments to measure the change in probe resistance compared to a protected reference element resistance series connected to the corroding measurement element A check element is also included and is protected from the process along with the reference element The ratio of check to reference resistance should remain constant If it doesn t this indicates that degradation of the reference element may be occurring and that metal loss readings obtained from the probe are questionable A simplified diagram of a typical electrical resistance monitoring circuit is shown in Figure 1 EXPOSED MEASURE ELEMENT PROTECTED REFERENCE WES PROBE CURRENT DRIVE R measure V measure CSince I meas I ref R ref V ref Figure 1 20 Theory As with coupons CORROSOMETER pro
17. nue Santa Fe Springs California 90870 United States of America Electrical Apparatus Model 4020LT A Corrosometer Transmitter Ontional accessory Type of Protection Intrinsically Safe Marking Ex ib IKZ Gb 40 C 10 80 Approved for issue on behalf af the A C Smsth Certification Body Position Certification Manager far prinfed version Date Ors 1 This certificate and schedule may only be reproduced in full 2 This certificate not transferable and remasns Ihe property of the issuing bady The Status and authenticity of this certificate may be verified by vesiting the Official IECEx Webaile CGartificale issued by SIRA Certification Service CSA Group Unit 6 Hawarden industrial Park vum sira 6 CHS 3U5 CERTIFICATION United Kingdom 31 32 Requirements for Intrinsic Safety Operation IECEx Certificate of Conformity Certificate IECEx SIR 14 0 Date of issue 2015 04 08 Issue 0 Page 2 3 Manufacturer Rohrback Cosasco Systems 11541 E Smith Avenue Fe Springs California 90670 United States of America Additional Manufacturing location This certificate is issued as verification that a sampleja representative of production was assessed and tested and found te comply with the IEC Standard list below and thal the manufacturer s quality system relating to ihe Ex product
18. osometer Transmitter 29 Certificate 70026842 Master Contract 252060 Project 70026942 Date Issued 2015 04 27 CONDITIONS OF ACCEPTABILITY L The equipment shall only be supplied from galvanically isolated interface The circuit is isolated from the enclosure but it is intended for connection to simple apparatus a corrosion probe which may not maintain isolation circuit tc earth ground as the probe corres In addition there is a facility for earthing the cable screen shield The circuit and screen shall be assumed to become connected due to cable damage The installer shall ensure that the system Le circuit and screen has no more than one connection to earth unless the two earths are connected together either via the structure or via an additional earth cable ii In the version with a plastic outer enclosure exposed plastic parts and non crounded metal parts may store an ignition capable level of electrostatic charge Therefor the userinstaller shall take precautions to prevent the build up of electrostatic charge e g locate the equipment where a charge zenerating mechanism such as wind blown dust 15 unlikely to be present and clean only with a damp cloth APPLICABLE REQUIREMENTS Safety Requirements for Electrical Equipment for Measurement Control and SANEA 03272 et CANICSA 22 2 No 61010 1 12 Ed 3 Laboratory Use Part 1 General Require ments CAN CSA C 2 7 6007 0 11 Ed 5 Explosive A
19. probe not covered by this certificate using the integral six wire shielded cable and connector the cable amp up 30 m 100 ft lang The eleciranics are a single encapsulated pried circuit board whech housed wilhin an miner metal enclosure An culter enclaaure which may he plastic ar metal provides additonal pratectian Carrasometer probe CONDITIONS OF CERTIFICATION YES as shown below 1 The equipment shall only be supplied from galvanically isolated interface The circuit ia isolated fram the enclosure but ia intended for connection to simple apparatus a comosion probe which may maintain 500 V isolation circuit Io earth ground as the probe corodes In addition there facility for earthing the cable The circuit and screen shall be assumed to become connected due to cable damage The installer shall ensure that the systern and screen hes no more than one connection to eanh unless the two earths are conmected together eather via the structure via an additional earth cable 2 In the version with a plastic auter enclosure exposed plastic parts and non grounded metal parts may store an ignitlon cagable level of electrostatic charge Therefore the user installer shall take precautions to prevent the bulk up of electrostatic charge e g locate the equipment where charg generating mechanism such s wind blawn dust is unlikely
20. react to temperature changes due to location of the reference and check elements concentrically inside the measure element 4020LT A Corrosometer Transmitter 25 Requirements for Intrinsic APPEN DIX Safety Operation To meet the requirements of the certifying authorities for the intrinsic safety certifications under which the equipment is operated it is important that the requirements of the certifications documents and installation practices are followed The following certification documents provide this information WARNING The transmitter has certifications for use with a safety barrier In general the process stream into which the CORROSOMETER probe is installed will determine if a safety barrier is required If this process stream is Classified as Class 1 Division 2 or Zone 1 by the jurisdiction of the applicable authority then a safety barrier MUST BE USED 26 Corrosometer Theory 1 d 3395 ATIVOISNIMINI 138VI wor CONMINMLIC J 5 VINISOJIIO SONIddS 31 VINYS 531545 0251500 9 00 WOUND 5 031219345 3SIMN3HIO 553 1510 S310N 960 HILLINSNYHL 3131005021205 V LY020F 130011 YSN 04906 WO SONINdS 34 VLNVS SNNSAV HLINS 5 315 5 ODSVSOO MOVSHHOH 4020LT A Corrosometer Transmitter 27 BA 092 30 55390133 OL 1039533 1 108 30 3900 Y SNOILION
21. robe Span mils 0 0254 U 4j Metal loss in uum P Probe Span mils 25 4 It is advisable to record the metal loss typically every five minutes and generate a graph of metal loss against time Visual display of the data is very useful to check general trends and the significance of any signal noise It is also helpful in determining the filter factor for the corrosion rate algorithm as detailed in the next section Corrosion Rate Calculation For Distributed Control Systems DCS we recommend a corrosion rate algorithm based on linear regression the best straight line with an adjustable filter factor The adjustable filter factor is obtained by varying the number or time period of readings m in the formula over which the liner regression is applied Readings are best taken every five minutes 14 Operation time period over which the data should be computed is 1 to 5 days with the ability to adjust this preferably on an individual probe channel basis 3 xi 24 x 1 Slope Corrosion rate where and y value of metal loss numbers corresponding to x time base values x the time base values m the number of points used for the regression Depending on the units chosen for x and y the corrosion rate may need to be converted to the rate units required As an example if y is in units of mils as determined from the
22. s covered by this certificate was assessed and found comply with the IECEx Quality system requirements This Certificate is granted subject to the conditions gs set aut in IECEx Scheme Rules 02 and Operational Documents gs amended STANDARDS The electrical apparatus and any acceptable variations to it specified in the schedule af thes certificate and the identified documents was found to comply with the following standards IEC 60079 0 2011 Explosive atmospheres Part General Edition 6 0 IEC 60079 11 2011 Explosive aimospheres Part 11 Equipment protection by intrinsic safety i Edition 6 0 This Certificate does not indicate compliance with electrical safety and performance requirements other than those expressly included in ihe Standards listed above TEST amp ASSESSMENT REPORTS sampnpie s of the eguipmment isted has successfully met the exameahon amd test requimements as recorded in GB SIR EXTR18 0092 00 Quality Assessment Report US ULAmAROB 0005 04 4020LT A Corrosometer Transmitter 33 IECEx Certificate of Conformity Certticate IECEx SIR 14 0107 X Date of Issue 2015 04 08 Issue Page 3 of 3 Schedule EQUIPMENT Equipment and systems covered by tus cenficate as follows The Model 4020LT A Corrosomater Transmitter is a 4 Zom loop powened instrument used for measurement of corrosion in process apphcabons The 4020LT A attached to
23. tmospheres Part 0 Equipment General require ments CAN CSA C 2 60079 14 Ed 6 Explosive Atmospheres Part 11 Equipment protection by intrinsic safety i 3 Safety Requirements for Electrical Equipment for Measurement Control and id 3 sirik E R Laboratory Use Part 1 General Require ments ANSI UL 60079 02013 Ed 6 Electrical Apparatus for Explosive Gas Atmospheres Part 0 General ANSPUL 6007 1 2013Ed 6 Electrical apparatus Atmospheres Part 11 Intrinsic Safety i DOD 307 Rew 2012 05 7 al pa 30 Requirements for Intrinsic Safety Operation Supplement to Certificate of Compliance Certificate 70026842 Master Contract 252069 The products listed includinp the latest revision described below are eligible to be marked in accordance with the referenced Certificate Product Certification History Project Date Description 70026947 2015 04 27 Onginal Certification of the Model 4020 Corrosometer 4020LT A Corrosometer Transmitter 18 ca IECEx Certificate 1 gt of Conformity INTERNATIONAL ELECTROTECHNICAL COMMISSION Certification Scheme for Explosive Atmospheres for rules and of IECEx Schame visit www com Cartficate SIR 14 0107X issue Certificate history Status Current Date of Issue 2015 04 08 1 f 4 Applicant Rohrback Cosasco Systems 11841 E Smith Ave
24. to present and only with a damp
25. typical two wire transmitter A DC supply of typically 24 VDC is required to power the 4 20mA loop The transmitter requires between 10 and 30 VDC at the transmitter terminals for correct operation NOTE If the environment for both the probe element in the process stream AND the transmitter are classified as Class 1 Division 2 or Zone 2 the transmitter may be used without a safety barrier see intrinsic safety certifications If either probe element OR transmitter are a Class 1 Division 2 or Zone 1 a safety barrier must used HAZARDOUS AREA SAFE AREA GALVANIGALLY ISOLATED 5 INTERFACE 4020LT A TRANSMITTER y TA VSH a 20V to 35V DC PROBE DISPLAY AND OR RECORDING DEVICE Figure 3 3Wiring Configurations Wth Safety Barriers 10 Installation Eee 4020LT A Corrosometer Transmitter 11 Operation CHAPTER 4 The output from a model 4020LT A transmitter is a 4 20mA signal that corresponds linearly to the range of zero to the probe span WARNING This linear output is different from the earlier model 4020 transmitter which had a non linear characteristic If using the 4020LT A to replace a model 4020 the conversion formula for the corrosion data must be modified Metal Loss From 4 20mA Signal To convert the 4 20mA signal into metal loss the conversion formula 5 as follows T Metal Loss mils Probe Span mils T 4 Metal Loss in mm 7 P
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