SM-5/SM-5A Portable Echo Sounder

Overview

The SM-5/SM-5A Portable Echo Sounder is a rugged, hand-held ultrasonic depth measurement instrument engineered for field-deployable hydrographic applications. It operates on the principle of time-of-flight acoustic pulse reflection—emitting a 200 kHz broadband chirp from an external piezoelectric transducer, measuring the round-trip travel time of the returning echo, and converting it to depth using the speed of sound in freshwater or seawater (default calibration assumes 1,480 m/s). Designed for operational simplicity and environmental resilience, the device delivers repeatable depth readings from small watercraft, shorelines, ice-covered lakes, or shallow coastal zones. Its high-visibility yellow housing, IP68-rated enclosure, and cold-tolerant electronics support reliable performance in maritime, fisheries, limnological, and marine safety workflows—including anchor-depth verification, bathymetric reconnaissance, and diver support operations.

Key Features

• External transducer with 3-meter shielded coaxial cable enables flexible mounting on hulls, kayaks, or ice auger holes without compromising unit portability.
• 200 kHz operating frequency provides optimal resolution for shallow-to-moderate depth profiling (0.6–79 m), with a narrow 24° beam angle minimizing side-lobe interference in cluttered environments.
• Real-time digital display with 10-second hold function allows manual recording or visual confirmation under variable lighting or motion conditions.
• IP68-certified housing withstands continuous submersion to 50 meters, validated per IEC 60529; robust against salt fog, UV exposure, and thermal cycling between –10°C and +50°C.
• Low-power architecture powered by a single 9 V alkaline battery, supporting approximately 500 discrete depth measurements at 10-second intervals—ideal for extended field surveys without external charging infrastructure.
• Unit-switchable output (feet/meters) accommodates regional operational standards and facilitates integration into legacy navigation logs or GIS data capture protocols.

Sample Compatibility & Compliance

The SM-5/SM-5A is compatible with freshwater, brackish, and seawater environments. While factory-calibrated for standard sound velocity in seawater (1,500 m/s) and freshwater (1,480 m/s), users may apply manual correction factors where salinity or temperature deviates significantly from nominal conditions (e.g., polar ice-covered lakes or estuarine mixing zones). The instrument complies with FCC Part 15 Class B emissions limits for unintentional radiators and meets RoHS 2 (2011/65/EU) directives for hazardous substance restriction. It is not certified for use in explosion-hazardous (ATEX/IECEx) or safety-critical navigation systems requiring IMO or IHO S-57 compliance; it serves as a supplementary depth reference tool—not a primary charting sensor.

Software & Data Management

The SM-5/SM-5A operates as a standalone analog-digital hybrid system with no onboard memory or USB/Bluetooth interface. All depth values are displayed in real time and must be manually logged or captured via external means (e.g., voice recorder, field notebook, or paired smartphone app using screen-recording functionality). For traceable QA/QC documentation, users are advised to implement standardized field log templates aligned with ISO 19901-3 (offshore survey quality management) or NOAA NOS guidelines for non-differential bathymetric validation. While the unit itself does not generate audit trails or electronic records, its consistent repeatability (±0.1 m typical under calm surface conditions) supports GLP-aligned data collection when used within defined SOPs.

Applications

• Nautical safety: Verifying safe anchorage depth prior to mooring in unfamiliar or poorly charted waters.
• Fisheries management: Mapping benthic relief to identify spawning habitats, submerged structures, or thermal layer transitions during seasonal stock assessments.
• Scientific limnology: Conducting rapid transect-based depth profiling across lakes, reservoirs, or glacial ponds—particularly where ice cover permits auger-hole deployment.
• Coastal zone monitoring: Supporting shoreline change analysis, sediment transport studies, and nearshore habitat mapping in conjunction with GPS-enabled mobile platforms.
• Recreational diving: Pre-dive verification of bottom topography and overhead clearance in cave or wreck penetration scenarios.

FAQ

Is the SM-5/SM-5A suitable for use under ice?

Yes—the transducer can be lowered through auger holes in black ice, and the unit’s low-temperature tolerance (–10°C minimum) ensures stable operation in frozen freshwater environments.
Does it support data export or connectivity to mapping software?

No—this is a dedicated readout-only instrument with no serial, USB, or wireless interface. Depth values must be recorded externally.
What is the accuracy specification under typical field conditions?

Manufacturer-stated resolution is 0.1 m (10 cm); actual field accuracy depends on water column homogeneity, transducer coupling, and surface wave height—typically ±0.15 m in calm, low-turbidity conditions.
Can the sound velocity setting be adjusted for different water types?

No—depth calculation uses fixed sound velocity presets (freshwater/seawater). Users must apply post-measurement corrections if operating outside standard salinity/temperature ranges.
Is the transducer compatible with third-party mounting hardware?

Yes—the transducer features a standard 3/8″-16 UNC threaded base and includes a rubber isolation gasket, enabling secure attachment to custom brackets, trolling motor arms, or ice fishing sleds.