ISCO 3700 Series Proportional Water Automatic Sampler

Overview

The ISCO 3700 Series Proportional Water Automatic Sampler is an engineered field-deployable instrument designed for regulatory-compliant, long-term unattended water sampling in municipal, industrial, and environmental monitoring applications. It operates on the principle of peristaltic vacuum aspiration—using a calibrated roller pump to draw representative samples from open channels, pipes, or flumes, then directing them into discrete or composite containers under programmable logic. Its core function is proportional sampling: collecting volumes weighted by real-time flow rate (via external flow meter input) or time intervals, ensuring statistically valid integration of pollutant loads over variable hydrologic conditions. This capability is essential for compliance with U.S. EPA Method 1664, ASTM D5905, and ISO 5667-10, particularly in wastewater discharge reporting, combined sewer overflow (CSO) characterization, and stormwater quality assessment.

Key Features

• Dynamic Head Compensation: Automatically adjusts pump speed and suction timing to maintain consistent sample volume across fluctuating water levels—critical for open-channel installations where stage height varies significantly.
• Self-Cleaning Probe System: Integrated air-purge and reverse-flush cycles eliminate carryover between samples, reducing cross-contamination risk without manual intervention.
• LD-90 Non-Contact Liquid Detection: Patented optical sensor (U.S. Patent 5,125,801) detects liquid presence independently of conductivity, turbidity, or viscosity—ensuring reliability across diverse matrices including brackish estuarine water, high-solids wastewater, and low-conductivity rainwater.
• NEMA 4X/6 (IP67) Controller Enclosure: Fully sealed, corrosion-resistant housing rated for submersion up to 1 m for 30 minutes; suitable for installation in wet wells, vaults, and flood-prone outfalls.
• Positive-Stop Indexing Distributor: Geneva mechanism precisely positions the sampling arm over each bottle location, eliminating positional drift and ensuring repeatable vial alignment—even after extended operation or vibration exposure.
• R-11 Insulated Transport & Dual-Wall Sample Chamber: High-density foam insulation and thermally decoupled inner chamber extend refrigerated hold time; supports >24-hour cold preservation when loaded with 13.5 kg of ice (3700 Full-Size model).
• Multi-Mode Programmability: Supports fixed-interval, variable-interval, flow-weighted, and event-triggered sampling—including EPA-compliant storm-event logic based on rainfall depth, stage rise rate, or flow threshold activation.

Sample Compatibility & Compliance

The 3700 Series accommodates standard 60–1000 mL polyethylene, HDPE, or glass sample containers (including EPA-approved amber vials for VOC analysis). It interfaces seamlessly with industry-standard flow measurement devices—including magnetic, ultrasonic, and area-velocity meters—via 4–20 mA, pulse, or SDI-12 inputs. All firmware and data logging functions comply with U.S. EPA Guidance for Electronic Records (40 CFR Part 136), support audit-trail generation, and meet GLP requirements for traceable sample chain-of-custody. The system’s calibration verification protocol aligns with ISO/IEC 17025:2017 Annex A.3 for automated samplers used in accredited environmental testing laboratories.

Software & Data Management

Data acquisition and configuration are managed via ISCO’s proprietary SamplerLink™ software (Windows-based), enabling remote setup, real-time status monitoring, and historical event log review. Each sample event is timestamped, annotated with flow rate, temperature, and alarm status, and stored in CSV-compatible format for integration into LIMS or SCADA platforms. Firmware supports secure password protection, user-level access control, and encrypted USB data export—meeting baseline requirements for FDA 21 CFR Part 11 electronic signature readiness when paired with validated procedural controls.

Applications

• Wastewater treatment plant effluent compliance monitoring (NPDES permit reporting)
• Combined sewer overflow (CSO) and sanitary sewer overflow (SSO) event characterization
• Urban stormwater runoff quality assessment (TMDL implementation)
• River, lake, and estuary loading studies under varying hydrologic regimes
• Industrial pretreatment program sampling (e.g., metal finishing, food processing)
• Non-point source pollution tracking in agricultural watersheds
• Regulatory grab-sample replacement for BOD, COD, TSS, nutrient, and microbiological analyses

FAQ

What flow measurement signals does the 3700 Series accept?
It accepts analog 4–20 mA, frequency/pulse outputs (0.1–100 Hz), and SDI-12 digital inputs from compatible flow meters.
Can the 3700 operate in freezing ambient conditions?
Yes—the controller housing and pump head are rated for –20 °C operation; optional heated probe kits prevent ice formation in intake lines.
Is the LD-90 sensor affected by biofilm buildup on the probe window?
No—its non-contact optical design eliminates fouling-related drift; routine visual inspection is recommended but cleaning is not required for function.
How is sample integrity maintained during extended deployment?
R-11 insulation, dual-wall thermal isolation, and programmable refrigeration cycle synchronization minimize temperature excursions—validated per EPA SW-846 Method 5035A for volatile preservation.
Does the system support remote diagnostics and firmware updates?
Yes—via RS-232/RS-485 serial interface or optional cellular modem module; updates are digitally signed and version-locked for security.