PONSEL Overflow Sensor (AQUALABO, France)

Overview

The PONSEL Overflow Sensor, engineered and manufactured by AQUALABO in France, is a purpose-built conductive-level detection device designed for qualitative, event-driven monitoring of surface water overflow in urban drainage, combined sewer overflow (CSO), and wastewater network infrastructure. It operates on a simple yet robust two-electrode conductivity principle: when a continuous conductive water film ≥0.5 mm bridges the stainless steel electrodes embedded in the PVC detector module, the circuit closes and triggers a non-polarized dry contact output signal. This binary (ON/OFF) response eliminates ambiguity in overflow event detection—ideal for applications where precise quantitative level measurement is unnecessary, but reliable, low-maintenance, and fail-safe event logging is critical. The sensor’s architecture separates sensing (detector module) from signal conditioning and power management (cylindrical electronics box), enabling flexible mounting in harsh, submerged, or intermittently flooded environments while maintaining long-term operational integrity.

Key Features

• True IP68-rated construction for both detector module and electronics enclosure—fully submersible and resistant to prolonged immersion in wastewater, stormwater, or brackish runoff.
• Conductive detection threshold precisely calibrated at 0.5 mm water film thickness—optimized to distinguish genuine overflow events from transient condensation or splashing.
• Non-polarized SPST dry contact output ensures compatibility with any industrial control system, data logger, SCADA input, or remote telemetry unit without polarity constraints or voltage compatibility concerns.
• Modular design: detector module mounts via two M5×40 anchor screws; electronics box features an integrated mounting ring for rapid panel or pipe attachment.
• Dual power options—long-life internal lithium battery (typical 3-year service life under standard duty cycles) or optional external +3.6 V ±5% supply for continuous operation in permanently powered monitoring stations.
• Fixed 9 m shielded, multi-strand polyurethane-sheathed interconnect cable ensures EMI resilience in electrically noisy sewer environments; output cables are pre-terminated with 1 m polyurethane-sheathed leads and bare tinned-copper ends for direct field wiring.

Sample Compatibility & Compliance

The PONSEL Overflow Sensor is chemically inert toward common municipal wastewater constituents, including suspended solids, organic matter, chlorides, sulfates, and moderate concentrations of ammonia and hydrogen sulfide. Its PVC housing and 316 stainless steel electrodes resist biofouling and corrosion under typical CSO and storm drain exposure conditions. While not certified to ISO/IEC 17025 for metrological traceability (as it delivers qualitative event detection, not quantitative measurement), the device complies with EN 60529 (IP68), EN 61000-6-2 (immunity), and EN 61000-6-4 (emissions). Its dry-contact interface supports integration into systems compliant with IEC 61508 (SIL2-capable architectures) and aligns with EU WFD (Water Framework Directive) requirements for event-based monitoring of unauthorized discharges.

Software & Data Management

As a hardware-level binary sensor, the PONSEL Overflow Sensor requires no embedded firmware, configuration software, or driver installation. Its output integrates natively with industry-standard data acquisition platforms—including Campbell Scientific CR series loggers, HOBO U12/U20 recorders, Siemens Desigo CC, and Schneider EcoStruxure Geo SCADA—via standard digital input channels. When deployed in networks with time-synchronized loggers, timestamped overflow events support correlation with rainfall intensity, flow meter data, and upstream water level trends. Audit-ready event logs—when captured under GLP-compliant procedures—can be archived with metadata (e.g., location ID, sensor serial number, UTC timestamps) to satisfy regulatory reporting obligations under national environmental agency guidelines (e.g., US EPA NPDES, UK EA General Binding Rules).

Applications

• Combined Sewer Overflow (CSO) event detection at outfall structures and retention basins.
• Qualitative identification of illicit wastewater discharges into storm drains (e.g., restaurant grease traps, industrial effluent bypasses).
• Real-time activation trigger for automatic sampling systems during first-flush storm events.
• Alarm generation for remote monitoring of pump station sump overtopping or manhole inundation.
• Validation of hydraulic model predictions during extreme precipitation events.
• Integration into smart city IoT infrastructure for urban flood early warning systems.

FAQ

What does “non-polarized dry contact” mean, and why is it advantageous?
It means the output switch has no inherent voltage polarity—either terminal can serve as common or switched—enabling universal compatibility with PLCs, RTUs, and data loggers regardless of their input circuit design.
Can the 9 m detector-to-box cable be extended or shortened in the field?
No. The 9 m length is factory-set and integral to EMC performance and signal integrity; field modification voids IP68 certification and invalidates warranty.
Is calibration required before deployment?
No. The sensor is factory-calibrated for 0.5 mm water film detection and requires no user calibration; verification may be performed using distilled water droplet test per AQUALABO Technical Note TN-PONSEL-03.
How is battery replacement handled after 3 years?
The sealed electronics box is not user-serviceable; end-of-life units must be returned to AQUALABO or authorized service centers for battery replacement and functional revalidation.
Does the sensor detect oil or hydrocarbon layers?
No. It responds only to conductive aqueous films; non-conductive liquids such as diesel, gasoline, or vegetable oil will not close the electrode circuit.