ISCO 2150 Portable Doppler Ultrasonic Flowmeter

Overview

The ISCO 2150 Portable Doppler Ultrasonic Flowmeter is an engineered solution for accurate, field-deployable open-channel and partially filled pipe flow measurement using the velocity-area method combined with continuous-wave (CW) Doppler ultrasonic technology. Unlike transit-time ultrasonic systems, the 2150 relies on acoustic scattering from naturally occurring suspended particles or entrained air bubbles—making it uniquely suited for wastewater, stormwater, irrigation runoff, and other turbid or aerated flows where signal integrity is often compromised. Its compact, lightweight design (0.9 kg) and robust NEMA 4X/6P (IP68) housing enable reliable operation in harsh outdoor environments—from manholes and culverts to temporary monitoring stations and remote catchments. The instrument integrates a digitally processed “smart” velocity-area probe in which water level analog signals are converted to digital format directly within the probe head—eliminating analog transmission errors and electromagnetic interference (EMI) susceptibility common in conventional analog-based systems.

Key Features

• Continuous-wave Doppler ultrasonic velocity sensing with automatic gain control and adaptive signal processing for stable readings in low-SNR conditions
• Digital water level transduction at the probe head—no analog voltage degradation over cable length
• Factory calibration across 120 reference points spanning 3-meter depth range and multiple temperature gradients (−40 °C to +60 °C), ensuring long-term zero and span stability without field recalibration
• Vented piezoresistive pressure sensor for real-time barometric compensation—critical for maintaining accuracy during diurnal atmospheric pressure shifts
• Epoxy-potted ultrasonic transducers with hydrophobic membrane and replaceable desiccant tube to prevent moisture ingress into the reference cavity and sustain sensor longevity in high-humidity or submerged deployments
• Modular architecture supporting up to four ISCO 2100-series flow modules via daisy-chained RS-232 expansion, enabling multi-point cross-sectional profiling
• Low-power electronics architecture achieving 15-month battery life (with Energizer® 529 alkaline cells) at 15-minute logging intervals—validated per IEC 60068-2 environmental test standards

Sample Compatibility & Compliance

The ISCO 2150 is validated for use with natural and engineered open channels containing particulate concentrations ≥20 ppm and bubble content sufficient to generate measurable Doppler shift—typical of municipal wastewater, combined sewer overflows (CSOs), agricultural drainage, and industrial effluents. It complies with ASTM D5941 (Standard Test Method for Determining Flow Rate Using Area-Velocity Procedures), ISO 748:2022 (Liquid flow measurement in open channels — Velocity-area method), and supports GLP/GMP-aligned data integrity through non-volatile flash memory storage with timestamped records. While not inherently 21 CFR Part 11 compliant out-of-the-box, its firmware architecture supports audit-trail-ready configurations when integrated with ISCO’s certified data acquisition software (e.g., FlowLink v5.2+), including user authentication, electronic signatures, and immutable log archiving.

Software & Data Management

Data is stored continuously in industrial-grade non-volatile flash memory—retaining all records through power loss, thermal cycling, or mechanical shock. Firmware updates are performed remotely via RS-232 at 38,400 bps without opening the enclosure or erasing existing programs or historical datasets. The embedded operating system supports programmable event-triggered logging: users define conditional rules (e.g., “log every 10 seconds if stage > 0.8 m”) to optimize memory utilization while capturing critical transient events such as CSO activation or pump start-stop cycles. Voltage and internal temperature are logged alongside flow metrics, enabling post-deployment diagnostics for battery health and thermal drift assessment. Export formats include CSV and ISCO-native binary (.flw), both compatible with third-party hydrologic modeling tools (HEC-RAS, SWMM) and LIMS integration via ODBC drivers.

Applications

• Short-term and permanent flow monitoring in sanitary sewers, storm drains, and combined sewer overflows (CSOs)
• Capacity verification and infiltration/inflow (I/I) studies per EPA Guidance for Wastewater Flow Monitoring
• Shallow-flow measurement in flumes, weirs, and low-gradient channels—validated down to 25 mm depth using low-profile probe geometry that minimizes flow disturbance
• Regulatory compliance reporting under NPDES permits requiring continuous flow mass balance documentation
• Field validation of fixed-installed electromagnetic or magnetic flowmeters in transitional or aerated flow regimes
• Hydrological research in ephemeral streams, constructed wetlands, and reclaimed water distribution networks

FAQ

Does the ISCO 2150 require calibration after probe replacement?
No. The smart probe architecture incorporates factory-applied digital calibration coefficients; swapping probes in the field does not necessitate recalibration.
Can the 2150 operate submerged indefinitely?
Yes. Its IP68/NEMA 6P rating certifies continuous submersion at depths up to 3 meters for 30 days—verified per IEC 60529 test protocols.
Is solar power integration supported?
Yes. ISCO offers optional solar-charging kits (e.g., 2191-SOLAR) compatible with the 2191 battery module, enabling year-round deployment in off-grid locations.
How is barometric pressure compensated during long-term deployments?
A vented piezoresistive sensor continuously measures ambient pressure and applies real-time correction to water level calculations—eliminating manual baro-correction workflows.
What communication protocols are supported?
RS-232 serial interface only (38,400 bps); no native Modbus, SDI-12, or cellular telemetry—external gateways required for SCADA integration.