The ABB AV400 Series Dissolved Organics Monitor is a sophisticated analytical instrument designed for continuous measurement of dissolved organic carbon (DOC) in various process fluids. It utilizes UV absorption as a non-specific, aggregate measurement technique, calibrated against potassium hydrogen phthalate standards. The monitor is available in single and dual input configurations, supporting both low and high range sensors.
Function Description:
The AV400 Series monitor operates by measuring the UV absorption of a sample at specific wavelengths. The sensor's emitter module contains an optical system with stable electronics, and the receiver module detects the transmitted light. The difference in light absorption between the sample and a reference signal is used to determine the dissolved organics concentration. The monitor can display readings in mgl⁻¹ of carbon, or in inferred units such as Absorbance/m, Color (°H), Coagulant Dose, or TOC, with user-defined conversion factors.
The system is designed for use in potable water treatment plants, coagulation/monitor/controller applications, and to detect the rise in DOC from algal bloom toxins. It incorporates a cleaning system to prevent fouling of the flowcell and maintain measurement accuracy. The monitor also features a comprehensive logbook to record alarm events, sensor errors, power failures, and calibration data.
Important Technical Specifications:
- Sensor Range (based on potassium hydrogen phthalate calibration standards):
- AV410/411 (Low Range): 0 to 20 mgl⁻¹ C
- AV420/422 (High Range): 0 to 100 mgl⁻¹ C
- Linearity:
- Low Range: ±2% of reading or 0.15 mgl⁻¹ C (whichever is greater)
- High Range: ±2% of reading or 0.5 mgl⁻¹ C (whichever is greater)
- Reproducibility:
- Low Range: ±0.15 mgl⁻¹ C
- High Range: ±0.5 mgl⁻¹ C
- Resolution:
- Low Range: 0.01 mgl⁻¹
- High Range: 0.1 mgl⁻¹
- Response Time: Normally three minutes for 90% step change, depending on damping factor.
- Lamp Life: Rated at 1.2 x 10⁹ flashes (10 years continuous operation at 2-second intervals).
- Display Type: Dual 4½-digit, 7-segment backlit LCD with a 16-character, single-line dot matrix for information.
- Current Outputs: Two fully isolated current outputs (0-10mA, 0-20mA, or 4-20mA), configurable to one or both sensor outputs. Programmable to any value between 0 and 22mA to indicate system failure.
- Relay Outputs: Three single-pole changeover relays (rating 5A 115/230V AC, 5A DC), configurable to one or both sensor inputs or status.
- Power Supply: 85 to 260V AC 50/60 Hz (optional 9 to 36V DC). Power consumption <24VA.
- Operating Temperature Limits: 0 to 50°C (32 to 122°F).
- Maximum Distance between Transmitter and Sensor: 750mm (29.5 in.).
- Enclosure Rating: IP66/NEMA 4X for the transmitter.
- Sensor Flow Rate: 0.5 to 5 l/min (free of air bubbles). Higher flow rates are required at high turbidity levels.
- Serial Communication: PROFIBUS (optional).
Usage Features:
The AV400 monitor offers a user-friendly interface with membrane keys for navigation and parameter adjustment.
- Operating Page: Displays real-time dissolved organics measurements, alarm set points, and operating information.
- Configurable Display Units: Users can select preferred display units (mg/l, mg/kg, ppm, Absorbance/m, Color (°H), Coagulant Dose, TOC, or user-defined).
- Filter Time: Adjustable from 1 to 10 minutes to average sensor signals and prevent short-term variations due to air bubbles.
- Alarm Configuration: Three programmable alarms with adjustable set points, hysteresis, and delay. Alarms can be configured as normal, failsafe, high/low, or status, and Alarm 3 can control the wash sequence.
- Analog Output Configuration: Two analog outputs can be assigned to Sensor A or Sensor B, with selectable current ranges (0-20mA, 0-10mA, 4-20mA) and span values. Default output behavior on failure (Off, On, Hold) is also configurable.
- Wash Function: Manual or automatic wash cycles can be initiated to clean the sensor. The wash function can be configured for continuous or pulsed operation, with adjustable frequency and duration.
- Logbook: Records up to 10 alarm entries, 5 error entries, and 5 calibration entries, including date and time of occurrence.
- Security Code: Access to configuration pages can be protected by a security code.
- Factory Settings: Allows configuration of sensor type, reference factor, and reference signal lower limit. Factory calibration matches the sensor's linearity characteristics to the transmitter.
- Language Selection: Supports English, French, German, Italian, and Spanish.
- Backlight Control: The LCD backlight can be set to always ON or Auto Off after 60 seconds.
Maintenance Features:
The AV400 Series monitor is designed with maintenance in mind, offering features to ensure long-term accuracy and reliability.
- Scheduled Maintenance: Regular cleaning of the flowcell is recommended, especially before calibration, to prevent contamination.
- Sensor Cleaning: Detailed procedures are provided for dismantling and cleaning the sensor, including the wiper blades and flowcell halves.
- Emitter and Receiver Module Replacement: Instructions are given for replacing these matched modules, emphasizing the importance of returning both to the Company for repair if one fails.
- Emitter Brightness Adjustment: A procedure to adjust the emitter brightness using a multi-turn potentiometer to ensure optimal signal levels.
- Calibration: The system supports zero and span calibration using high purity water and potassium hydrogen phthalate standard solutions. Calibration checks can be performed to verify system accuracy.
- Diagnostics: Provides status messages for various conditions such as "Lamp Disabled," "Out of Sample," "Low Signal," "Cleaner Fail," and hardware faults, along with recommended actions.
- De-bubbler (Optional): An optional de-bubbler unit can be installed to prevent air bubbles from causing unstable or erratic readings, particularly in low-level sensor applications.
- Cable Entry Knockouts: The transmitter case is equipped with knockouts for cable glands, allowing for secure and organized electrical connections.
- Relay Contact Protection: Recommendations for fitting resistor/capacitor networks (for AC loads) or diodes (for DC loads) to protect relay contacts from erosion due to arcing and to suppress RFI.
- Load/Save Configuration: Allows users to save and load system configurations, simplifying setup and maintenance.
Need help?
To Next Page
General