Horiba D-55 Portable Multi-Parameter Water Quality Analyzer (pH, DO, Temperature)

Overview

The Horiba D-55 is a handheld, multi-parameter water quality analyzer engineered for field-deployable and laboratory-grade measurement of pH, dissolved oxygen (DO), and temperature in aqueous samples. It operates on electrochemical principles: pH and ORP are measured via potentiometric detection using glass or polymer-bodied combination electrodes; dissolved oxygen is quantified using Clark-type polarographic membrane sensors with built-in temperature compensation; and temperature is acquired via integrated platinum resistance (Pt1000) or thermistor-based ATC probes. Designed for environmental monitoring, wastewater treatment, aquaculture, and drinking water verification, the D-55 delivers traceable, repeatable data under variable ambient conditions — including immersion in rain, splashing, or temporary submersion.

Key Features

• IP67-rated rugged enclosure ensuring dust-tight operation and protection against immersion up to 1 m for 30 minutes
• Simultaneous real-time display of pH (0.00–14.00), DO (0.00–19.99 mg/L), and temperature (0–100 °C)
• High-resolution measurements: 0.01 pH unit, ±0.01 pH accuracy; 0.01 mg/L DO resolution with ±0.01 mg/L typical repeatability
• Automatic temperature compensation (ATC) across full 0–100 °C range, eliminating manual correction steps
• Internal memory capacity for 300 measurement records with timestamp and parameter identifiers
• 9 V alkaline battery power supply supporting >100 hours of continuous operation (typical usage)
• Compact ergonomic design (18 × 8 × 6 cm) optimized for one-handed operation in confined or remote sampling locations

Sample Compatibility & Compliance

The D-55 is validated for use with freshwater, seawater (with salinity compensation), wastewater effluents, surface runoff, and process water streams. Its sensor interface supports interchangeable Horiba-certified electrodes—including the 9096000500 DO probe and 9621-10D/9611-10D pH/ATC combinations—ensuring compatibility with ISO 5814 (DO measurement), ASTM D888 (oxygen solubility), and EPA Method 360.1 (pH). The instrument meets IEC 61000-4 electromagnetic immunity standards and complies with GLP documentation requirements through traceable calibration logs stored internally. While not FDA 21 CFR Part 11–certified out-of-the-box, audit-ready data export (via optional RS232 cable 9096004800) supports GMP-aligned workflows when paired with validated third-party software.

Software & Data Management

Data retrieval is enabled via optional RS232 serial interface (cable model 9096004800), compatible with Horiba’s proprietary PC software for calibration history tracking, trend analysis, and CSV export. Each stored record includes date/time stamp, measured values, electrode ID (if encoded), and operator-defined sample ID. Calibration verification reports include slope (%), offset (mV), and response time — critical for ISO/IEC 17025-compliant labs. Firmware updates are distributed through Horiba’s global technical support portal and require no hardware modification.

Applications

• Field-based compliance monitoring per national water quality standards (e.g., China’s GB 3838, EU WFD parameters)
• Biochemical oxygen demand (BOD) pre-screening and saturation assessment in activated sludge systems
• Aquaculture pond management — rapid DO and pH checks to prevent hypoxia or acidosis events
• Source water characterization during emergency response (e.g., post-spill or flood events)
• Educational laboratories requiring robust, low-maintenance instrumentation for undergraduate environmental science curricula
• Calibration verification of fixed online DO/pH analyzers in municipal water plants

FAQ

Does the D-55 support automatic salinity compensation for DO measurements?

Yes — it applies algorithmic correction based on user-input or auto-detected salinity (0.00–4.00 %), aligned with the Weiss equation for oxygen solubility in saline media.
Can the D-55 be used for continuous immersion or flow-through applications?

No — it is rated IP67 for temporary submersion only. For continuous monitoring, Horiba recommends the companion ES-51 with flow-cell electrodes or the U-50 series multiparameter sondes.
What calibration protocols does the D-55 follow?

Two-point pH calibration (4.01/7.00/10.01 buffers), zero-current DO calibration in sodium sulfite solution, and single-point temperature validation using NIST-traceable reference thermometers.
Is electrode diagnostics available during measurement?

Yes — the device displays electrode impedance status, membrane integrity warnings (for DO), and slope deviation alerts post-calibration to flag aging or fouled sensors.
Are calibration certificates provided with purchased electrodes?

Horiba-certified electrodes ship with individual factory calibration reports (including K-factor, sensitivity, and offset values), compliant with ISO/IEC 17025 traceability requirements.