Hanna HI98301 Portable Microprocessor-Based Low-Range TDS Meter

Overview

The Hanna HI98301 is a compact, handheld microprocessor-based Total Dissolved Solids (TDS) meter engineered for field and laboratory applications requiring reliable, low-range conductivity-derived TDS quantification in aqueous solutions. It operates on the principle of electrical conductivity measurement—converting conductance readings (µS/cm) into TDS values (ppm or mg/L) using a fixed linear conversion factor (typically 0.5–0.7, factory-set to 0.5 for HI98301), suitable for non-ionic or weakly ionic solutions such as drinking water, bottled water, hydroponic nutrient solutions, aquarium water, and pre- and post-filtration monitoring in point-of-use systems. The instrument features an integrated two-electrode graphite sensor with built-in temperature compensation, eliminating the need for external probes or manual correction. Its design adheres to fundamental electrochemical measurement standards—including ASTM D1125 (Standard Test Methods for Electrical Conductivity and Resistivity of Water) and ISO 7888 (Water quality — Determination of electrical conductivity)—ensuring traceable, repeatable results across environmental, food & beverage, and municipal water quality workflows.

Key Features

• Microprocessor-controlled operation with dual-line LCD display for simultaneous TDS and temperature readouts
• Integrated graphite two-electrode sensor with robust chemical resistance and rapid response time (< 3 seconds to 95% stability)
• Automatic single-point calibration recognition at 1382 ppm (25°C), compatible with Hanna’s certified traceable standards HI7032 or HI70032
• Full-range automatic temperature compensation (ATC) from 0 to 50°C, using an embedded NTC thermistor with ±0.5°C accuracy
• Three programmable auto-off intervals (8 min, 60 min, or off) to conserve battery life without compromising measurement continuity
• IP67-rated housing (dust-tight and submersible up to 1 m for 30 min) for operation in humid, wet, or outdoor environments
• Low-power consumption design powered by a single 3V CR2032 lithium coin cell (typical battery life > 2000 measurements)

Sample Compatibility & Compliance

The HI98301 is validated for use with low-conductivity aqueous samples including potable water, reverse osmosis (RO) permeate, distilled/deionized water, and dilute electrolyte solutions. It is not intended for high-ionic-strength media (e.g., seawater, brines, or concentrated industrial effluents) due to its 0–2000 ppm range limitation. All materials in contact with sample—including the graphite electrode surface and ABS/PC housing—are compliant with FDA 21 CFR §177.2420 (indirect food additives: polymeric substances) and EU Regulation (EC) No 1935/2004. The device supports GLP-compliant documentation when used with calibrated standards traceable to NIST SRM 3191a (KCl conductivity standard). While not inherently 21 CFR Part 11 compliant (as it lacks electronic signature or audit trail functionality), its calibration log, date/time stamping (via optional PC interface cable), and stable firmware enable integration into GMP-aligned QC procedures for routine water testing.

Software & Data Management

The HI98301 operates as a standalone instrument with no onboard data logging memory. However, it is compatible with Hanna’s HI92000 Windows-based software via optional USB-to-serial adapter (HI92000-01), enabling real-time data streaming, calibration history export (CSV/Excel), and timestamped report generation. Each measurement includes embedded temperature metadata and calibration status flags, supporting ISO/IEC 17025 Clause 7.7 (Ensuring validity of results) through documented traceability. Firmware updates are available through Hanna’s official support portal and require no hardware modification—ensuring long-term regulatory alignment without obsolescence risk.

Applications

• Drinking water quality verification per WHO Guidelines for Drinking-water Quality (TDS < 600 mg/L recommended)
• RO and deionization system performance validation in pharmaceutical water purification loops
• Hydroponic and aquaculture nutrient solution monitoring (optimal TDS ranges: 500–1200 ppm for leafy greens; 1000–2000 ppm for fruiting crops)
• Environmental field screening of surface and groundwater per EPA Method 120.1 (Conductivity)
• Food & beverage process control—e.g., syrup dilution verification, brewing water profiling, and dairy rinse water assessment
• Educational laboratories for introductory electrochemistry and water chemistry experiments

FAQ

What calibration standard is required for the HI98301?
The meter is factory-programmed to recognize Hanna’s HI7032 (1382 ppm KCl at 25°C) or HI70032 (certified reference material) for single-point calibration. Use only certified standards with documented uncertainty ≤ ±1.5%.

Can the HI98301 measure conductivity directly?
No—it displays only TDS (ppm) and temperature. Conductivity values are internally calculated but not user-accessible; for direct µS/cm output, consider the HI98302 or HI98308 models.

How often should the graphite electrode be cleaned?
Clean after each use with Hanna’s HI7061L electrode cleaning solution (30-minute soak), especially following exposure to organic films, calcium carbonate, or colloidal suspensions. Rinse thoroughly with deionized water before storage.

Is the HI98301 suitable for wastewater analysis?
Not recommended for raw or secondary-treated wastewater due to potential fouling and TDS concentrations exceeding 2000 ppm. For such applications, select a higher-range meter with platinum or stainless-steel electrodes and multi-point calibration capability.

Does the HI98301 meet ISO/IEC 17025 requirements for accredited labs?
Yes—as a verified measuring instrument, provided calibration is performed using traceable standards, environmental conditions are recorded, and measurement uncertainty is estimated per ISO/IEC 17025 Annex A.3 (using ±2% F.S. + ±0.5°C temp error propagation).