ATAGO PR-100SA Seawater Salinity Refractometer

Overview

The ATAGO PR-100SA Seawater Salinity Refractometer is a compact, field-deployable optical instrument engineered for rapid, on-site determination of salinity in natural seawater, artificial marine solutions, and brackish aquaculture media. It operates on the principle of critical-angle refractometry: incident light passes through a prism-sample interface, and the resulting refraction angle—directly correlated to the solution’s refractive index—is converted into salinity concentration (expressed in parts per thousand, ‰ w/w NaCl equivalent) via a calibrated optical scale. Unlike laboratory-grade benchtop refractometers requiring temperature stabilization, the PR-100SA integrates Automatic Temperature Compensation (ATC) across its full operating range (5–40°C), eliminating manual correction and ensuring consistent measurement validity under variable ambient conditions typical in mariculture, coastal monitoring, or aquarium maintenance environments.

Key Features

• True handheld design with ergonomic grip and lightweight construction (300 g), optimized for extended field use without fatigue.
• Digital LCD display with 1‰ resolution provides unambiguous, real-time readout—no subjective interpretation of analog scales required.
• ATC system employs a bimetallic thermal element embedded in the prism block, dynamically adjusting the optical path to offset refractive index drift caused by sample temperature fluctuations between 5°C and 40°C.
• IP64-rated enclosure ensures resistance to dust ingress and water splashes—suitable for humid docks, wet lab benches, and outdoor marine stations.
• Single-button START/OFF operation minimizes procedural error; measurement completes within 3 seconds after sample application.
• No external calibration tools needed—factory-calibrated against NIST-traceable NaCl standards; user verification possible using distilled water (0.0‰) or certified reference seawater.

Sample Compatibility & Compliance

The PR-100SA is validated for aqueous saline solutions containing sodium chloride as the dominant solute, including natural seawater, synthetic sea salt mixes (e.g., Instant Ocean®, Reef Crystals®), and low-viscosity brines used in larval rearing tanks or coral propagation systems. It is not intended for non-aqueous solvents, highly turbid suspensions, or solutions containing significant concentrations of organic solutes (e.g., glycerol, ethanol) that alter refractive index independently of ionic strength. While not certified to ISO/IEC 17025 for accredited testing, its measurement traceability aligns with ASTM D1141 (Standard Practice for Preparation of Artificial Sea Water) and supports routine quality control in GLP-compliant aquaculture facilities where salinity stability is critical to osmoregulatory health of marine organisms.

Software & Data Management

As a standalone optical instrument, the PR-100SA does not incorporate onboard data logging, Bluetooth connectivity, or PC interface capabilities. All measurements are displayed in real time and must be manually recorded. This architecture prioritizes mechanical reliability, battery longevity (>5,000 measurements per 9V cell), and immunity to electromagnetic interference—key requirements in electromagnetically noisy environments such as vessel engine rooms or power-supply-dependent hatcheries. For laboratories requiring audit trails, users may integrate PR-100SA readings into LIMS or electronic lab notebooks via manual entry, with operator ID, timestamp, and environmental notes documented per FDA 21 CFR Part 11 guidance where applicable.

Applications

• Aquaculture facility management: Daily verification of salinity in broodstock tanks, larval rearing systems, and recirculating aquaculture systems (RAS).
• Marine aquarium maintenance: Precise adjustment of synthetic seawater during water changes or top-off procedures.
• Environmental field surveys: Rapid assessment of estuarine salinity gradients, tidal pool variability, and freshwater intrusion monitoring.
• Education and training: Undergraduate marine science labs demonstrating principles of solution density, osmotic pressure, and optical property relationships.
• Quality assurance in sea salt production: Batch screening of evaporation pond brines prior to crystallization.

FAQ

Does the PR-100SA measure conductivity or specific gravity?
No. It measures refractive index and converts it to salinity (‰ w/w NaCl) using an optical calibration curve. Conductivity meters and hydrometers provide complementary—but physically distinct—measurements.
Can I use it for measuring brine used in food processing?
It is calibrated for NaCl-dominated aqueous systems; accuracy may degrade in high-sugar or high-acid brines (e.g., pickling solutions) due to non-linear refractive index contributions.
How often should I clean the prism surface?
After every measurement—especially when switching between samples—to prevent cross-contamination and residue buildup that affects optical clarity.
Is the 9V battery replaceable in the field?
Yes. The battery compartment is accessible via a single Phillips screw; standard 006P alkaline cells are globally available and require no specialized tools for replacement.
What does the “±2‰” accuracy specification represent?
This is the maximum permissible error at any point within the 0.0–100‰ range under defined conditions (20°C ambient, clean prism, proper sample application), per ATAGO’s internal validation protocol aligned with JIS Z 8015.