HORIBA HP-300 Industrial Online pH Meter

Overview

The HORIBA HP-300 is an industrial-grade, outdoor-rated online pH meter engineered for continuous, reliable monitoring of aqueous process streams and environmental effluents in demanding operational environments. Designed as part of HORIBA’s H-1 series of ruggedized water quality analyzers, the HP-300 employs a potentiometric measurement principle based on the Nernst equation, utilizing a glass pH electrode paired with a stable reference system to deliver high-fidelity, real-time pH data under variable temperature and flow conditions. Its architecture integrates analog signal conditioning, digital self-diagnostic logic, and temperature-compensated output—all housed within a single, weather-resistant enclosure. The device is purpose-built for unattended operation in wastewater treatment plants, chemical manufacturing lines, cooling tower circuits, and municipal discharge monitoring stations where long-term stability, minimal maintenance, and regulatory traceability are critical requirements.

Key Features

• IP65-rated aluminum alloy housing ensures robust protection against dust ingress and low-pressure water jets—suitable for permanent outdoor installation without additional sheltering.
• Large-format LED display enables at-a-glance verification of pH and temperature values, along with status indicators for calibration history, electrode health, and system diagnostics.
• Integrated Pt1000 and optional thermistor-based temperature compensation (500 Ω / 6.8 kΩ / 10 kΩ at 25 °C) supports accurate automatic temperature compensation across the full 0–100 °C operating range.
• Isolated 4–20 mA analog output complies with industrial control system standards; maximum loop resistance of 600 Ω facilitates direct integration with PLCs, DCS, or SCADA platforms without signal repeaters.
• Comprehensive self-diagnostic capability monitors electrode response slope, asymmetry potential, reference junction integrity, and internal circuit anomalies—flagging out-of-spec conditions prior to measurement drift.
• Screw-type terminal blocks prevent accidental disconnection in high-vibration environments; all wiring access points are sealed per IP65 specifications.
• Conforms to CE (EMC & LVD), FCC Part 15 Class A, RoHS Directive 2011/65/EU, and WEEE Directive 2012/19/EU—certified for use in regulated industrial and municipal infrastructure.

Sample Compatibility & Compliance

The HP-300 is optimized for liquid-phase measurements in conductive aqueous media—including raw sewage, treated effluent, process rinse water, boiler feedwater, and industrial cooling fluids—with typical conductivity >50 µS/cm. It is not intended for non-aqueous solvents, highly viscous slurries, or samples containing suspended solids exceeding 1% w/w without appropriate pre-filtration or flow-cell configuration. Electrode selection (e.g., double-junction, gel-filled, or refillable reference systems) must be matched to sample chemistry to avoid poisoning or clogging. While the instrument itself does not carry ISO/IEC 17025 accreditation, its measurement traceability aligns with ISO 5667-22 (water quality sampling) and ASTM D1293 (standard test method for pH of water), supporting GLP-compliant data recording when paired with validated data loggers or LIMS interfaces.

Software & Data Management

The HP-300 operates as a standalone transmitter and does not require proprietary software for basic operation. However, its 4–20 mA output supports seamless integration into third-party supervisory systems that comply with IEC 61131-3 or OPC UA protocols. Calibration events—including date/time stamp, buffer values used, slope/mV offset, and temperature—are stored in non-volatile memory and retrievable via front-panel navigation. For audit readiness, users may configure external historians to capture timestamped analog outputs alongside metadata (e.g., calibration flags, diagnostic alerts). Though the unit lacks native Ethernet or Modbus RTU, optional signal converters enable compatibility with FDA 21 CFR Part 11–compliant environments when deployed with electronic signature-enabled SCADA layers and audit-trail-enabled databases.

Applications

• Real-time pH control in neutralization basins and chemical dosing loops for wastewater treatment compliance (e.g., EPA NPDES permit limits).
• Process monitoring of rinse baths, etching tanks, and plating solutions in semiconductor and metal finishing facilities.
• Continuous verification of boiler feedwater alkalinity to prevent corrosion and scale formation in power generation and HVAC systems.
• Effluent discharge monitoring at industrial outfalls subject to local environmental agency reporting requirements (e.g., EU Urban Wastewater Treatment Directive).
• Integration into multi-parameter water quality stations measuring concurrent parameters such as ORP, conductivity, residual chlorine, and turbidity—when deployed alongside compatible HORIBA H-1 series sensors.

FAQ

What types of pH electrodes are compatible with the HP-300?
The HP-300 accepts standard BNC or DIN-style pH electrodes with integrated temperature sensing (Pt1000 or thermistor). HORIBA recommends its own F-70 series or compatible industrial-grade electrodes rated for continuous submersion and chemical resistance.

Does the HP-300 support automatic temperature compensation?
Yes—it supports automatic temperature compensation using either built-in Pt1000 sensing or externally connected thermistors (500 Ω, 6.8 kΩ, or 10 kΩ at 25 °C), configurable via front-panel menu.

Can the HP-300 be calibrated remotely?
No—calibration requires physical access for buffer immersion and manual initiation via the keypad; however, calibration history and diagnostic logs are retained for remote review via connected control systems.

Is explosion-proof certification available for the HP-300?
The standard HP-300 is not ATEX or IECEx certified; for hazardous area deployment, consult HORIBA’s intrinsically safe transmitter variants or zone-specific enclosures.

What is the expected service life of the HP-300 under continuous operation?
With proper electrode maintenance and periodic verification (recommended every 3–6 months), the transmitter electronics exhibit >10-year operational reliability per IEC 60721-3-3 Class 3K5 environmental endurance testing.