SANXIN PH5S Pen-Style pH Meter with Puncture Electrode

Overview

The SANXIN PH5S is a rugged, field-ready pen-style pH meter engineered for precision measurement in both liquid and semi-solid matrices. Unlike conventional immersion-only pH meters, the PH5S integrates a Swiss-manufactured puncture-type pH electrode—designed with a robust, tapered glass sensing tip and integrated reference junction—to enable direct insertion into soft, heterogeneous, or viscous samples without sample preparation. Its electrochemical architecture follows standard potentiometric principles: the potential difference between the pH-sensitive glass membrane and Ag/AgCl reference electrode is converted to a stable mV signal, then linearized and temperature-compensated using the Nernst equation. The instrument operates across an extended pH range of –2.00 to 16.00, supporting applications from strongly acidic fermentation broths to highly alkaline cleaning solutions used in food processing and pharmaceutical manufacturing. With automatic temperature compensation (ATC) from 0 to 50 °C and built-in diagnostics, the PH5S delivers repeatable, traceable measurements compliant with routine QC workflows in regulated environments.

Key Features

• Integrated puncture pH electrode optimized for semi-solid and soft-surface applications—including cheese, sushi rice, meat cuts, fruit pulp, dough, cosmetic gels, and hydroponic substrates
• Tri-color STN LCD backlight: blue (measurement mode), green (calibration mode), red (alarm mode)—enabling rapid visual status recognition in variable lighting conditions
• 1–3 point auto-calibration with support for NIST-traceable buffers (pH 4.00, 7.00, and 10.01); user-selectable buffer sets accommodate regional calibration standards (China NIST or USA NIST)
• Automatic temperature compensation (0–50 °C) with ±0.5 °C accuracy and 0.1 °C resolution, minimizing thermal drift during field deployment
• IP67-rated housing—fully dust-tight and submersible up to 1 m for 30 min; instrument floats on water surface for accidental drop recovery
• Extended battery life (>200 hours continuous use) powered by four standard AAA alkaline cells; auto-power-off after 8 minutes of inactivity
• Simultaneous mV (ORP) measurement capability (±1000 mV, 1 mV resolution, ±0.2% FS), compatible with optional ORP electrodes for redox process monitoring

Sample Compatibility & Compliance

The PH5S is validated for direct measurement in non-homogeneous, low-moisture, and high-viscosity samples where conventional dip electrodes yield unstable readings or risk breakage. Its puncture electrode design eliminates the need for homogenization or filtration—reducing contamination risk and preserving sample integrity per ISO 29541 (food pH testing) and AOAC Official Method 973.41. The instrument meets IEC 60529 (IP67), CE marking requirements for portable electrochemical instrumentation, and supports GLP-compliant data recording when paired with external logging software. While not FDA 21 CFR Part 11–certified as a standalone system, its calibration history, auto-diagnostic logs, and parameter lockout features align with audit readiness expectations for routine environmental and production line testing.

Software & Data Management

The PH5S operates as a self-contained, embedded-system device with no onboard memory or Bluetooth/Wi-Fi connectivity—ensuring electromagnetic immunity in industrial settings and eliminating cybersecurity exposure. All configuration parameters—including alarm thresholds, auto-off delay, backlight duration, and buffer selection—are retained in non-volatile memory after power cycling. Users document measurements manually or via external loggers; the HOLD function freezes stable readings for transcription. For laboratory integration, the mV output mode allows analog connection to chart recorders or DAQ systems. Calibration events are indicated by visual prompts and audible beeps, and self-diagnostics verify electrode impedance and circuit integrity before each measurement cycle.

Applications

• Food quality control: real-time pH verification in dairy curds, fermented meats, bakery dough, and ready-to-eat seafood preparations
• Aquaculture and hydroponics: spot-checking nutrient solution acidity in recirculating aquaponic systems and vertical farms
• Water treatment: rapid assessment of disinfection efficacy (e.g., chlorine stability at varying pH) in cooling towers, spas, and municipal distribution points
• Cosmetics R&D: batch consistency checks for emulsions, gels, and creams where surface pH correlates with skin compatibility
• Educational labs: hands-on electrochemistry instruction emphasizing electrode geometry, junction potential, and temperature effects on Nernstian response

FAQ

What types of semi-solid samples can be measured directly with the puncture electrode?
Cheese blocks, tofu, sausage slices, fruit flesh (e.g., apple or banana), baked goods (dough, cake batter), cosmetic creams, and hydrogel-based substrates—provided the material permits clean insertion without excessive resistance or electrode coating.
Is the PH5S suitable for ISO/IEC 17025-accredited laboratories?
Yes—as a secondary or field-use instrument—provided users maintain documented calibration records, perform daily verification with check standards, and validate electrode performance per ISO 17488 before critical measurements.
Can the instrument store calibration history or measurement data?
No—the PH5S does not include internal memory or export functionality. All calibration and usage logs must be maintained externally in accordance with organizational SOPs.
What maintenance is required for the puncture electrode?
Rinse with deionized water after each use; store immersed in 3 M KCl solution; avoid drying out or contact with strong solvents, proteins, or sulfides that may clog the reference junction.
Does the PH5S comply with USP or EP 2.2.3 guidelines for pH measurement?
It satisfies the general instrumental requirements (accuracy ±0.01 pH, resolution 0.01 pH, ATC) outlined in these pharmacopeial chapters; however, final method validation must be performed by the end user under actual application conditions.