ABB AX400 Series AX460/AX466 pH/ORP Analyzer User Guide

ABB AX400 Series AX460/AX466 pH/ORP Analyzer User Guide

ABB AX460/AX466 Single and Dual Input pH/Redox Potential Analyzer: A Professional Choice for Industrial Process Analysis

In the fields of industrial process control, water treatment, environmental monitoring, etc., accurate measurement of pH value and oxidation-reduction potential (ORP) is a key link to ensure product quality, process efficiency, and environmental compliance. As a global leader in process automation technology, ABB has launched the AX460 and AX466 series pH/Redox (ORP) analyzers with over a century of experience in instrument design and manufacturing. This user guide aims to provide users with comprehensive information on operation, installation, programming, and maintenance to ensure optimal performance and long-term reliability of the equipment.

Company Background and Quality Commitment

ABB is a world leading company in the design and manufacturing of instruments for industrial process control, flow measurement, gas and liquid analysis, and environmental applications. As a part of ABB Group, we are committed to teamwork, high-quality manufacturing, advanced technology, and unparalleled service and support. The quality, accuracy, and performance of the company's products are based on over 100 years of experience, combined with continuous innovative design and development plans to incorporate the latest technologies.

The NAMAS calibration laboratory (number 0255) is only one of the ten flow calibration devices operated by the company, which fully reflects our dedication to quality and accuracy. The company's quality management system has passed international standard certification, ensuring that every piece of equipment leaving the factory meets strict quality requirements.

Product Overview and System Description

The AX460 (single input) and AX466 (dual input) series pH/Redox (ORP) analyzers are designed for continuous monitoring and control of pH values and redox potentials. These analyzers, together with the accompanying electrode system, form a complete measurement solution.

Core features:

Flexible input configuration:

AX460: Provides single channel pH or ORP input with independent temperature input channel.

AX466: Provides dual channel pH or ORP inputs, each with an independent temperature input channel.

Supports standard pH input (single high impedance input,>10 ¹³ Ω) or differential pH input (dual high impedance input, both>10 ¹³ Ω). Differential input design is used for pH electrode systems equipped with solution grounding rods. By measuring the signals of the measuring electrode and reference electrode separately and comparing them with the solution ground potential, more accurate pH values can be obtained.

Temperature compensation: When conducting temperature compensation measurements, the sample temperature is sensed by a resistance thermometer (Pt100, Pt1000, or Balco 3K) installed in the electrode system to ensure measurement accuracy.

Automatic cleaning function: All models are equipped with cleaning facilities for system cleaning. Alarm 3 relay can be configured to automatically or manually control the cleaning system. Programmable control of continuous or pulse signals to control solenoid valves or pumps powered by external sources. The frequency, duration, and recovery time of the cleaning cycle can be programmed. During the cleaning cycle, the simulated output value remains in its pre cleaning state.

User interface: The operation and programming of the analyzer are completed through five tactile film buttons on the front panel. The programming function is protected by a four digit security code to prevent unauthorized changes.

Automatic detection: The analyzer automatically detects the type of input board installed for each input and only displays the frame applicable to that input board type. If the input board for sensor B is not installed, the sensor B frame will not be displayed.

Operation Guide

1. Power on and startup

Ensure all connections are correct, especially the grounding bolts.

Ensure that the input sensor is properly connected.

Connect the power supply. The startup screen will be displayed, along with an internal check, and then the operation page will be displayed, starting the pH or ORP monitoring operation.

2. Display and Control

The display screen includes two rows of 4 and a half digit 7-segment digital displays, displaying the actual values of measurement parameters and alarm setpoints, as well as a 6-character dot matrix display, displaying relevant units. The next line is a 16 character dot matrix display that displays programming information.

Key functions (see Figure 2.2):

A key: Move between menus

B key: Forward to the next page

C key: Move between parameters

D key: Adjust and store parameter values

E key: Select and store parameter options

3. Operation page

The operation page displays different information based on the model and configuration:

Single input pH: displays pH value, temperature, alarm status, etc.

Dual input pH: displays the pH value, temperature, alarm status, etc. of sensors A and B.

Single/dual input Redox (ORP): displays mV values, temperature, etc.

Cleaning function: If alarm 3 is configured for cleaning, the operation page will display the cleaning status and manual start option.

Programming and Configuration

The programming menu allows users to customize the behavior of the analyzer according to specific application requirements. Entering programming mode usually requires entering security code.

1. Configure display

The contrast ratio and backlight mode of the display screen can be configured (normally on or automatically turned off after 60 seconds) to adapt to different environmental lighting conditions and achieve energy saving.

2. Configure sensors

Probe type: Select the measurement type (pH or Redox/ORP) for each input channel.

Temperature sensor type: Select the type of RTD connected (Pt100, Pt1000, or Balco 3K).

Measurement unit: Select the temperature unit (° C or ° F).

Solution temperature compensation coefficient: For applications that require process solution compensation, a compensation coefficient can be configured.

Calibration options: Enable or disable sensor calibration function, set calibration low limit (slope), etc.

3. Configure alarms

The analyzer comes standard with 3 alarm relays, which can be expanded to 5 if an optional board is installed. Each alarm can be independently configured:

Alarm allocation: Assign alarms to specific sensors or parameters (such as pH A, temperature B, etc.).

Alarm type: can be selected as high alarm, low alarm, or diagnostic alarm.

Fault safety: Select whether to enable the fault safety mode (relay action when power is off).

Setpoint: Set the threshold for triggering an alarm. PH Setpoint Range: -2.00 to 16.00 pH; mV Setpoint Range: -2000 to 2000 mV; Temperature Setpoint Range: -10.0 to 150.0 ° C or 14.0 to 302.0 ° F.

Lag: A differential set point of 0% to 5% of the programmable set value to prevent frequent shaking of alarms near the threshold.

Delay: Set the delay time (0 to 60 seconds) between the occurrence of an alarm condition and the activation of the relay/LED.

Special Function of Alarm 3- Cleaning Cycle Configuration:

When alarm type 3 is set to "Wash", the following parameters can be configured:

Cleaning frequency: 5 minutes to 24 hours, fully configurable.

Cleaning duration: 15 seconds to 10 minutes, fully configurable.

Recovery cycle: 30 seconds to 5 minutes, fully configurable.

Cleaning signal type: continuous signal or pulse signal (pulse on and off time can be set).

4. Configure output

Analog output: Two (standard) or four (optional) fully isolated analog outputs can be configured. The output current can be selected from 0-10mA, 0-20mA, or 4-20mA. Each output can be assigned to any measured variable (pH, mV, or temperature). Programmable output points to any value between 0-22mA in case of system failure to indicate the fault status.

Maximum load resistance: 750 Ω at 20mA.

Accuracy: ± 0.25% FSD, ± 5% reading.

Resolution: 0.1% at 10mA, 0.05% at 20mA.

5. Configure clock and log

Real time clock: records time and date, used for logging and automatic cleaning functions (optional board required).

Log: Electronic recording of major process events and calibration data (optional board required). Configurable event types and frequencies for logging.

6. Configure security

Security code: Set a four digit code to protect programming functionality. Disable security protection when the code is set to zero.

7. Test output and maintenance

Provide manual testing simulation output and relay functions for easy debugging and troubleshooting.

Sensor calibration

AX460/AX466 offers multiple flexible calibration modes to ensure measurement accuracy.

1. Set buffer type (pH only)

You can choose from the preset buffer table:

ABB

DIN 19266

Merck

NIST

US Tech

Two user-defined buffer tables

2. User defined buffer solution

Allow users to manually input the pH values of two buffer solutions at different temperatures to match non-standard buffer solutions.

3. Automatic and manual single/two-point calibration (pH only)

Single point calibration: used to adjust zero offset.

Two point calibration: Simultaneously adjust the zero point and slope to achieve optimal accuracy.

Automatic stability check: During the calibration process, the analyzer will automatically monitor the signal stability and only record the calibration point after the signal is stable.

Calibration message:

PASSED: The new calibration coefficient has been accepted (with a slope of 40% to 105%).

CAL LOW SLOPE: Calibration passed, but electrode pair fatigue, recommended replacement (slope 60% to 90%).

PH CAL FAILED: Calibration failed, ignoring new coefficients and retaining the last valid coefficient (slope 0% or 40% to 70%). Check the buffer value and repeat calibration. If the fault persists, replace the electrode.

4. Offset adjustment (Redox/ORP only)

Used to compensate for the potential drift of the reference electrode by measuring a known standard solution and adjusting the offset.

5. Capture calibration (pH only)

Allow single point calibration using process samples to align analyzer readings with laboratory reference values.

Installation Guide

1. Site selection requirements

Installed in a location without excessive vibration.

Stay away from harmful vapors and/or dripping fluids.

It is best to install it at eye level for unobstructed viewing of the front panel display and controls.

2. Installation method

Wall mounted/pipe rack installation: Provide installation brackets that can be installed on walls or vertical pipes. Protection level IP66/NEMA4X.

Panel installation: 96mm x 96mm standard size, suitable for control panel installation. The front panel protection level is IP66/NEMA4X.

3. Electrical Connections (General Precautions)

Grounding: The power ground must be connected to ensure personnel safety, reduce the impact of RFI interference, and ensure the correct operation of the power interference filter. The chassis is equipped with grounding bolts for busbar grounding.

Cable wiring: Always separate the signal output/pH electrode cable from the power line/relay cable, ideally using a grounded metal conduit. Use twisted pair output leads or shielded cables, and connect the shielding layer to the chassis grounding bolt.

Cable entry: Ensure that the use of cable connectors, conduit fittings, and blind plugs does not damage the NEMA4X/IP66 rating.

Relay: The relay contacts are pressure free contacts and must be connected in series with the power supply and the alarm/control equipment to be driven. Ensure that the contact rating is not exceeded.

4. Relay contact protection and interference suppression

When a relay is used to switch loads, the contacts will corrode due to arcing. Electric arcs can also generate radio frequency interference, which may cause analyzer malfunctions and reading errors. To minimize the impact of RFI, arc suppression components are required:

Communication application: Use a resistor/capacitor network (it is recommended to initially use a 100 Ω/0.022 μ F RC suppressor, part number B9303).

DC application: Use diode (recommended IN5406 type, 600V peak reverse voltage, 3A, part number B7363).

5. Terminal connection

Sensors A/B: Connect them correctly according to the electrode type (with or without solution grounding) and temperature compensator type (2-wire or 3-wire) as shown in Figure 6.9 or 6.11 of the manual.

Analog output: Connect to the corresponding+and - terminals.

Alarm relay: connected to the common terminal (C), normally open terminal (NO), or normally closed terminal (NC).

Calibration verification and troubleshooting

1. Factory setup

The analyzer has been calibrated before leaving the factory, and routine recalibration is not necessary. It is recommended to attempt recalibration only when the input board has been replaced or the calibration has been tampered with. Before attempting to recalibrate, use appropriately calibrated testing equipment to test the accuracy of the analyzer.

Required equipment: millivolt source, decimal resistance box, digital milliampere meter.

Preparation: Disconnect the electrode and output, connect the analog device, and calibrate according to the overall factory setup flowchart in Figure 7.2 of the manual.

2. Simple troubleshooting

Error message:

A: FAULT PT100/A: FAULT PT1000/A: FAULT BALCO: The temperature compensator or connection of sensor A is open or short circuited.

A: CAL LOW SLOPE/B: CAL LOW SLOPE: Electrode fatigue, replacement recommended.

A: PH CAL FAILED/B: PH CAL FAILED: Calibration failed, check the buffer and repeat. If the fault persists, replace the electrode.

WASH INHIBITED: The cleaning function in the operation page needs to be set to off and turned on.

Calibration failure or no response to pH/Redox changes:

Most issues are related to electrodes and cables. As a preliminary inspection, replace the electrode.

Check that all program parameters are entered correctly and have not been accidentally changed.

Use a pH simulator to check the response of the analyzer to millivolt input. If the analyzer does not respond to the input, there may be a fault and it needs to be returned for repair.

Perform impedance check. If the test fails, check whether there is moisture inside the transmitter, especially in the terminal box, and use a hot air dryer to remove the moisture.

Check temperature input: Disconnect the RTD lead, connect the resistance box directly to the analyzer input, and check whether the value displayed by the 

Detailed technical specifications

Parameter specifications

Input 1 or 2 pH/mV inputs (AX466) and the solution ground; 1 or 2 temperature sensors (AX466)

Input resistance glass electrode>1 × 10 ¹³ Ω; reference electrode 1 × 10 ¹³ Ω

Measurement range pH: -2.00 to 16.00; ORP: -1200 to+1200 mV

Minimum range: Any 2 pH or 100 mV

Resolution 0.01 pH

Precision 0.01 pH

Temperature compensation automatic or manual Nernst compensation; Process solution compensation (configurable coefficient)

Temperature compensation range -10 to 150 ° C (14 to 302 ° F)

Temperature sensor programmable Pt100, Pt1000 or Balco 3K

Display dual 5-digit 7-segment backlit LCD; 16 character single line dot matrix information display

Analog output with 2 channels (standard) or 4 channels (optional) completely isolated; 0-10mA, 0-20mA or 4-20mA; maximum load 750 Ω @ 20mA

Relay outputs 3 (standard) or 5 (optional); Single blade double throw; 5A，115/230V AC，5A DC

Controller type (AX460) P, PI, PID (configurable)

Proportional range of 0.1 to 1000%, with 0.1% step size

Integral time (reset) 1 to 7200 seconds, 1-second step (0=off)

Differential time 0.1 to 1000 seconds, 0.1 second step

Communication Modbus serial data interface

Power supply 85 to 265V AC 50/60Hz; Optional 24V AC or 12 to 30V DC

Power consumption<10VA

Environmental temperature (working) -20 to 65 ° C (-4 to 149 ° F)

Environmental humidity (working) up to 95% RH, no condensation

Protection level wall mounted/pipe rack type: IP66/NEMA4X; Panel type: Front panel IP66/NEMA4X

EMC complies with EN61326 (industrial environment) EN50081-2、EN50082-2

Safety compliance with EN61010-1, input/output overvoltage level II, pollution level 2

Explosion proof certification CENELEC ATEX IIG EEx n IIC T4 (TBD); FM/CSA Non Motivational Class I Div.2 Groups A-D (TBD)

Language options include English, French, German, Italian, and Spanish

AX460

AX466

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AX411

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