ROHRBACK COSASCO 9030 Plus User Guide
Serial Number _____________
9030 Plus™
CORRATER® INSTRUMENT
USER MANUAL
ROHRBACK COSASCO SYSTEMS, INC.
11841 E. Smith Avenue
Santa Fe Springs, CA 90670
Tel: (562) 949-0123
(800) 635-6898
Fax: (562) 949-3065 P/N 710680-MANUAL
Rev. E (12/07)
© 2002 Rohrback Cosasco Systems, Inc. All rights reserved.
CORROSOMETER®, CORRATER® and CORROTEMP® are registered trademarks 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.
Contents
Chapter 1 Introduction ................................................................................1
Chapter 2 Specifications...............................................................................5
Chapter 3 Installation...................................................................................9
Chapter 4 Operation...................................................................................15
Chapter 5 Maintenance..............................................................................21
Chapter 6 Data Logger Function and Set Up Using Corrdata Plus ......25
Appendix A
Theory of Operation of CORRATER Systems .................................46
i
ii 9030 Plus Reference Manual
Figures and Drawings
Figure Page
1-1 Picture of 9030 Plus Unit .........................................................................................................1
3-1 Mounting and Unit Dimensions of 9030 Plus..........................................................................9
3-2 Installation Wiring Connections ............................................................................................11
3-3 Probe Orientation Relative to Flow........................................................................................12
3-4 Probe Orientation at a Tee Fitting ..........................................................................................12
3-5 Probe Cable Color Connections .............................................................................................13
Table Page
5-1 CORRATER Multiplier Factors.............................................................................................22
Appendix A Page
A-1 Equivalent Circuit of LPR Probe...........................................................................................47
A-2 Typical LPR Current vs. Time Decay Curve ........................................................................48
A-3 Operating Rate of LPR Instruments
Corrosion Rate vs. Solution Conductivity............................................................................49
A-4 Rohrback Cosasco 3-Electrode
Probe Configuration..............................................................................................................50
Chapter 1
1
Introduction
GENERAL
The 9030 Plus single or two-channel CORRATER® instrument is a field-installed corrosion monitor for
cooling, process or potable water systems. The 9030 Plus CORRATER® system is designed to help
improve facility operations by enabling the user to directly monitor corrosion rate, imbalance, and
temperature — all automatically and continuously without operator intervention. The display on the unit is
autoranging to maintain high sensitivity regardless of the parameter being measured. The information may
also be data logged when CORRDATA® Plus software is used to configure the instrument and retrieve
data.
Figure 1-1 Front View of 9030 Plus Unit
2 9030 Plus Reference Manual
CORRATER® systems operate on the fundamental principle that a metal corroding through oxidation will
generate a small electrical current. A CORRATER® instrument determines the corrosion rate by
measuring the current from a small applied potential difference between the two electrodes. The 9030 Plus
extends the practical solution resistance range for LPR measurements. It measures the electrochemical
impedance by use of a patented AC technique, which automatically compensates for the solution resistance
between the corrosion measuring electrodes. It does this without resorting to a third electrode or
correction curves. The 9030-Plus is, however, compatible with all two or three-electrode probes already in
use. A discussion of the LPR method of corrosion rate measurement is presented in Appendix A of this
manual.
The 9030 Plus performs temperature measurements when reading suitable CORROTEMP® CORRATER®
probes. These probes measure temperature with a platinum resistance temperature device (RTD) located
inside the probe near the process end. By measuring the RTD resistance, the 9030 Plus can calculate and
display the water temperature present at the probe location.
The 9030 Plus is designed for the convenience of the user. Automatic solution resistance compensation
improves the utility, convenience and accuracy of corrosion rate measurements. The 9030 Plus also
monitors a form of Electrochemical Current Noise (ECN) between the electrodes called imbalance (or
pitting tendency). This is a qualitative and very useful indication of instability in the material surface
consistent with pitting or localized corrosion.
A total of six 4-20 mA current loop drivers are provided to remotely monitor the corrosion rate, imbalance
and temperature measurements. For convenience, the loops are designated as follows:
4 -20 mA Loop (Number) Description of Output
1 Probe 1 Corrosion Rate
2 Probe 1 Imbalance
3 Probe 1 Temperature
4 Probe 2 Corrosion Rate (Two-Channel Instruments Only)
5 Probe 2 Imbalance (Two-Channel Instruments Only)
6 Probe 2 Temperature (Two-Channel Instruments Only)
These six electrically isolated 4-20 mA current sourcing loop outputs provide convenient connection(s)
to other recording and computing devices. For local monitoring, a vacuum fluorescent display makes it
easy to read the measured data or change initial setup parameters. An internal relay, with programmable
set points for both corrosion rate and imbalance, is available for external alarm or control circuit
connection.
3
After installation, the operator only needs to perform an initial setup to set the cycle time (if other than
automatic), probe multiplier or other parameters of interest. Initial setup is performed via four front panel
keys while monitoring the display. The operation section of this manual contains a description of user
definable parameters. In some cases, initial setup may not be required since factory defaults have been set.
A weatherproof NEMA 4X enclosure houses the instrument. Four mounting tabs on the rear corners of the
instrument enclosure provide permanent mounting. All probe cables exit at the bottom of the instrument.
The unit includes one or two standard 10 foot probe cables and an AC line cord. Cables for the 4-20 mA
loops and the setpoint relay can be fabricated for specific installations.
4 9030 Plus Reference Manual
5
Chapter 2
Specifications
OPERATIONAL
Channels:
1 or 2 Channels CORROTEMP® CORRATER® input
Probe Compatibility:
All two-electrode CORRATER
flush type electrodes. The instrument is also compatible with three-electrode CORRATER
®
and CORROTEMP® CORRATER® probes with either standard or
Corrosion Rate Ranges:
Autoranging from 0.01 to 1,000 MPY
Imbalance Ranges: (pitting index)
Autoranging from 0.01 to 1,000 pitting units. (1 pit unit = 2.5 microamperes)
Cycle Time Range:
Independent cycle time for probe channels 1 and 2.
Automatic or manually adjustable 3 to 30 minutes in 1/2 minute increments. Default is 5 minutes.
(Polarization time is 25 % of cycle time)
Multiplier Range:
0.50 to 3.00 in steps of 0.01. The multiplier compensates for the differences between electrode
materials, electrode sizes, and abnormal operating conditions. Default multiplier is 1.0 (mild steel).
Temperature Measurement:
Range: -40 °C to +260 °C.
Accuracy: +
Repeatability: +
Resolution: 0.1 °C.
2 °C (Excluding sensor)
1.0 °C.
Analog Isolated Output Ranges:
Corrosion Rate and Imbalance: 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000 MPY or pitting units.
Temperature: -40 °C to +260 °C
®
probes.
6 9030 Plus Reference Manual
Control / Alarm Setpoint Relay:
Independently set levels for corrosion rate and imbalance. Continuously adjustable from 0 to 999
MPY.
Data Logger
Independent data logger function for each probe, operates with CORRDATA® Plus Software through
isolated RS232 interface from personal computer. 1023 readings per channel. (511 readings for
temperature capable CAT probe). Minimum time between readings with logger is 30 minutes.
:
ENVIRONMENTAL
Instrument Operating Temperature:
32 °F - 122 °F (0 °C - 50 °C)
Storage temperature:
-4 °F to 131 °F (-20 °C to +55 °C)
Enclosure:
One circuit card housed in a 6 x 6 x 4 inch NEMA 4X enclosure.
Mechanical
Size:
See Figure 3.1
Unit Weight:
6 Lbs.
Probe to Instrument Cable Length:
CORRATER
CORRATER
Barrier type Compatibility: MTL 755 and 761 (See Figure 3-5)
Display:
Vacuum Fluorescent Technology (Blue)
®
Without Barrier: 2000 feet (610 m) maximum
®
With Barrier: 1300 feet (396 m) maximum
Chapter 2 Specifications 7
INTERFACE
Probe:
10 foot integral probe cable with type B connector compatible with all CORRATER® probes and type
C or type S probe connecting adapters for MODEL 6080 high pressure probes.
Power Requirements:
Switch selectable 115 or 230 volt operation 47 - 63 Hz, factory set as specified by user. Instrument
power consumption is 15 watts, nominal.
105-125 VAC or 210-250 VAC, 8 foot power cable with stripped and tinned conductors with standard
IEC color code.
Isolated Analog Outputs:
Six 4-20 mA current drivers which can be calibrated at the 4 and 20 mA endpoints.
Maximum load resistance 600 Ohms. NOTE: This device sources current for all loops.
6 process measurements assigned to 6 analog outputs:
Loop 1: Probe 1 Corrosion Rate
Loop 2: Probe 1 Imbalance
Loop 3: Probe 1 Temperature
Loop 4: Probe 2 Corrosion Rate (Two-Channel Instruments Only)
Loop 5: Probe 2 Imbalance (Two-Channel Instruments Only)
Loop 6: Probe 2 Temperature (Two-Channel Instruments Only)
Control/Alarm Setpoint Relay:
Maximum current capacity: 1 Amp @ 230 VAC resistive load, SPDT.
Data Logger:
Isolated RS232 interface to personal computer running CORRDATA® Plus Software.
8 9030 Plus Reference Manual
9
Chapter 3
Installation
GENERAL
The 9030 Plus is a field-mountable instrument that is designed to be mounted on a wall, bulkhead or other
flat surface. Mounting tabs, fastened to the back panel of the instrument, protrude beyond the NEMA 4X
enclosure and allow mounting to a flat surface. Figure 3-1 provides dimensional information for mounting
the unit.
Figure 3-1 Mounting and Unit Dimensions of 9030 Plus Unit
10 9030 Plus Reference Manual
Power
The ON/OFF switch for the unit is inside the NEMA 4X enclosure mounted on the printed circuit board
near the front of the instrument. The fuse holder (standing vertically next to the ON/OFF toggle switch)
contains a T500 milliamp 250 volt 5X20mm fuse (RCS replacement PN 098003-13). NOTE: Fuse must
be replaced with the exact type in the unit to maintain CE compliance.
The instrument is supplied with an 8 foot power cable which is terminated with a standard three-prong
plug for 115 volt operation or stripped and tinned conductors with standard IEC color code (LIVE-brown,
NEUTRAL-blue, GROUND-green/yellow) for 230 volt operations.
CAUTION: The power supply voltage must correspond to that selected by the slide switch located
inside the unit. The switch is clearly marked and should be properly set at the factory.
WARNING! To protect operating personnel it is necessary that the instrument be grounded .
To accomplish this, the offset (round) prong on the furnished power plug must be connected
to the facility ground. In addition to this, when wiring the setpoint relay, 4-20mA loops or
probe cables, it is recommended that power be completely removed from the instrument.
Even if the ON/OFF switch is in the OFF position, the AC mains are still connected to some
circuitry within the unit and represent a shock hazard. Damage to the unit could also occur
if operating personnel accidentally touch high voltage circuits with tools during initial wiring
setup.
Chapter 3 Installation 11
Figure 3-2 Installation Wiring Connections
CORRATER® Probes
The 9030 Plus is intended to be used with any standard 2-electrode CORRATER
probes can also be used, but for simplicity and economy, it is recommended that 2-electrode probes be
used. Probes with replaceable cylindrical electrodes are generally referred to as "standard" probes, and
probes with disc electrodes are referred to as "flush" probes because the electrodes are flush with the end
surface of the probe. The probes are available in many designs including fixed, adjustable, retractable and
retrievable mounting configurations.
®
probes. Three electrode
12 9030 Plus Reference Manual
Also, probe electrodes are available in many element and alloy materials. The material selected should
closely match the material of construction of the pipe or vessel for which corrosion information is desired.
Probes should be installed where corrosion is most likely to be greatest so that readings will truly represent
the most aggressive system corrosion rates. Preferably, they should be located where the liquid flow
velocity past the electrode exceeds 1 foot per second (0.3 m/sec.) if it is required to measure corrosion
rates representative of a flowing environment. Alignment of the electrodes relative to the direction of
process flow is important to obtain reliable corrosion rate measurements. Proper alignment is with the
imaginary line connecting the center lines of the two electrodes perpendicular to the direction of the
process flow. Refer to Figure 3-3. With this orientation, one electrode does not "shade" the other
electrode, and both are subject to nearly the same corrosive environment. If a probe is installed in an
elbow fitting, where flow changes direction, position the probe so that the electrodes "face" the oncoming
flow. Refer to Figure 3-4.
Figure 3-3 Probe Orientation Relative Figure 3-4 Probe Orientation at
to Flow a Tee Fitting
Chapter 3 Installation 13
Probe Connection
The 9030 Plus is supplied with either one or two probe cables, dependent on the configuration of the unit.
Each cable is ten feet long and terminated in a 6 pin type "B" connector. The type "B" connector is
suitable for direct connection to all CORRATER® probes. The only exception is interconnection to a
Model 6080 High Pressure CORRATER® probe where a fixed probe connecting adapter is also required.
The cable length can be extended up to 2000 feet if desired. Since the cables are internally shielded, it is
not recommended that extender cables be used since the internal shield is not propagated through the
standard 6 pin connector. Cables of any length can be ordered from the factory with the "B" connector on
one end, and the other end stripped and tinned ready for user installation to the instrument. (See Figure 3-
2)
The two probe cables are connected through weather proof glands to screw terminal connectors that plug
into the circuit board mounted on the inside front cover of the instrument enclosure. Using a small flat
bladed screw driver, the probe cables can be removed. The probe cable consists of 3 twisted pairs and one
ground shield. The schematic diagram below depicts the wire colors and appropriate connector pin
assignments. The probe connector pin designations, connector P3 for Probe 1, and connector P2 for Probe
2, are marked on the printed circuit board silk screen.
Figure 3.5 Probe Cable Color Connections
To minimize pickup of electromagnetic interference, care should be taken to route cables clear of heavy
current cables and devices. Routing probe cables inside grounded conduit tubing provides the best
immunity against EM interference. For conduit installations, AC power wires should not be in the same
conduit as the probe cables.
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