ROHRBACK COSASCO SYSTEMS CORRATER 9020, User Manual

Page 1: ...__________ MODEL 9020 9020 OEM CORRATER TRANSMITTER USER MANUAL ROHRBACK COSASCO SYSTEMS INC 11841 East Smith Avenue Santa Fe Springs CA 90670 Tel 562 949 0123 800 635 6898 Fax 562 949 3065 P N 710900 Manual Rev E 10 07 ...

Page 2: ...red trademark 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 ...

Page 3: ...ts Chapter 1 Introduction 1 Chapter 2 Specifications 3 Chapter 3 Installation 5 Chapter 4 Operation 11 Appendix A Probe Multiplier Values 13 Appendix B Imbalance Measurement Function of CORRATER Instruments 15 ...

Page 4: ...ii ...

Page 5: ...nt capability and therefore should not be used with CORROTEMP CORRATER probes The Model 9020 OEM Figure 1 is a complete transmitter module for mounting in a customer provided secondary enclosure while the Model 9020 Figure 2 consists of the transmitter module mounted in a NEMA 4X IP 66 weatherproof enclosure suitable for field mounting Either is supplied with a five foot cable with connector which...

Page 6: ...Installed in Enclosure Connection to the CORRATER probe to be monitored is made with the six foot two meter cable supplied with the instrument A 5 MPY mil per year test probe is provided with the instrument for the purpose of verifying proper instrument operation ...

Page 7: ...0 minutes Resolution 0 1 of Full Scale Alloy Multiplier Range 0 2 to 2 99 Ambient Temperature Range 18ΕC to 60ΕC Supply Voltage Range 16 32 VDC at 20 mA MECHANICAL Enclosure Model 9020 OEM 16 Ga Aluminum Box Model 9020 NEMA 4X IP66 Weight 2 lbs 1 Kg Cable Six foot Two meter with Type B connector MISCELLANEOUS Compatibility All 2 electrode and 3 electrode CORRATER probes ...

Page 8: ...CORRATER Transmitter User Manual 4 Figure 3 Dimensions of 9020 OEM Figure 4 Dimensions of 9020 NEMA Enclosure ...

Page 9: ...ent please inspect all items for shipping damage and retain any damaged materials to support any claim against the freight carrier should this become necessary Installation Procedure Installation of the 9020 OEM and 9020 consists of three tasks Mechanical mounting of the transmitter Electrical connections to the transmitter and probe Verification of instrument operation Selection of parameters for...

Page 10: ...dimensions on transmitter The Model 9020 is intended to be field mounted on a panel wall or other vertical surface The NEMA 4X enclosure is mounted using four 1 4 machine screws through the mounting feet Dimensions for the mounting holes are shown in Figure 6 ...

Page 11: ...e and 4 20 mA loop cables enter the 9020 enclosure through sealing glands Both the 9020 OEM and the 9020 are provided with six foot CORRATER probe to instrument cables which are already terminated on the instrument If for some reason the cable must be removed and reconnected the individual conductors in the cable should be terminated to the instrument in accordance with Figure 7 ...

Page 12: ...irectly adjacent to the probe cable gland on the bottom of the enclosure A two conductor cable with shield is recommended for wiring to the 4 20 mA connections If only corrosion rate measurement is required the connections are made to the two position terminal strip labeled CORROSION If only imbalance measurements are required the connections are made to the two position terminal strip labeled IMB...

Page 13: ... complete the verification testing Selection of Parameters for Corrosion Rate Monitoring To place the transmitter into operation disconnect the Test Probe and connect the cable to the CORRATER probe to be monitored Set the CORROSION RANGE switch to the position that exceeds the maximum corrosion rate to be expected i e Position 2 20 MPY if the maximum expected rate is 12 MPY Set the IMBALANCE RANG...

Page 14: ... of the multiplier with the left hand switch selecting the units value 0 1 or 2 the center switch selecting the 1 10 s value 0 0 0 9 and the right hand switch selecting the 1 100 s value 0 00 0 09 Set the STANDARD FLUSH toggle switch for STANDARD if using a probe with protruding 5 0 square centimeter electrodes or select FLUSH if using a probe with flush 0 5 square centimeter electrodes Enable the...

Page 15: ...follows CORROSION RATE MPY IL 4 16 X CORROSION RANGE selected To convert the 4 20 mA Signal into IMBALANCE UNITS the conversion formula is as follows IMBALANCE 2 5 µA unit IL 4 16 X IMBALANCE RANGE selected The constant of 2 5 µA per IMBALANCE UNIT is equivalent to a current density of 0 5 µA per square centimeter of electrode area and has been determined empirically so that the magnitude of the i...

Page 16: ...CORRATER Transmitter User Manual 12 ...

Page 17: ...CDA 642 A1 Silicon Bronze 1 48 C68700 CDA 687 Alum Brass Arsenical 1 62 C70610 CDA 706 90 10 Copper Nickel 1 80 C71500 CDA 715 70 30 Copper Nickel 1 50 G41300 AISI 4130 Alloy Steel 1 00 L50045 Lead 2 57 N04400 Monel 400 Nickel 1 13 N05500 Monel K 500 Nickel 1 04 N06022 Hastelloy C22 0 85 N06600 Inconel 600 Nickel 0 95 N08020 Carpenter 20 CB3 SST 0 98 UNS Code Material Multiplier N08800 Incolloy 80...

Page 18: ...CORRATER Transmitter User Manual 14 ...

Page 19: ...localized conversion of iron atoms to ferrous ions since a small anodic area can be supported by the larger cathodic area As this iron oxidation proceeds the small cavity grows which in turn exposes a larger iron surface that is essentially void of oxygen causing it to be a very active anode This process which has the natural tendency to accelerate describes the growth of a corrosion pit Since sus...

Page 20: ...mperes µa which scales to a current density of 0 5µa cm2 the CORRATER electrode surface area is 5 cm2 The scale factor above was established from empirical data so that the relative magnitudes of corrosion rates in mils per year MPY and imbalance readings could be compared At this scale factor the dominant corrosion mechanism is the one which exhibits the greater magnitude i e corrosion rate imbal...