SANXIN PHB-2 Portable pH Meter
| Brand | SANXIN |
|---|---|
| Model | PHB-2 |
| pH Range | 0.0–14.0 pH |
| Resolution | 0.1 pH |
| Accuracy | ±0.1 pH |
| Temperature Compensation | 0–80 °C (manual) |
| Input Impedance | ≥3×10¹¹ Ω |
| Power Supply | 6F22 / 9 V battery |
| Dimensions | 168 × 43 × 26 mm |
| Weight | 170 g |
| Operating Environment | 5–35 °C, ≤85% RH |
Overview
The SANXIN PHB-2 Portable pH Meter is a compact, field-deployable electrochemical instrument engineered for reliable and repeatable pH measurement in diverse laboratory, educational, environmental, and industrial settings. Based on the potentiometric principle, it measures the hydrogen ion activity in aqueous solutions via a pH-sensitive glass membrane electrode coupled with a stable reference system. The meter employs a high-input-impedance amplifier (≥3×10¹¹ Ω) to minimize signal drift and ensure accurate voltage-to-pH conversion, critical for low-conductivity or high-resistance samples. Designed for operational simplicity and rugged portability, the PHB-2 delivers calibrated performance across the full physiological and process-relevant pH scale (0.0–14.0 pH), with manual temperature compensation enabling correction for thermal effects on electrode response between 0 °C and 80 °C.
Key Features
- True portable architecture: Lightweight (170 g) and compact (168 × 43 × 26 mm) housing with integrated battery compartment for uninterrupted field use.
- High-impedance input circuitry ensures minimal loading error and stable readings, especially with low-ionic-strength samples such as deionized water or biological buffers.
- 0.1 pH resolution and ±0.1 pH accuracy meet ISO 3696 Grade 3 and ASTM D1293 requirements for routine quality control applications.
- Manual temperature compensation using an included glass thermometer allows precise adjustment without requiring built-in thermistor integration—ideal for cost-sensitive, education-focused, or maintenance-minimized deployments.
- BNC-compatible interface supports interchangeable SANXIN pH composite electrodes (e.g., 201-C, 200-C, 206-C, 2015P-C), enabling adaptation to sample geometry, surface measurement, or micro-volume analysis.
- Powered by a single 9 V alkaline battery (6F22), providing extended operational life and globally accessible replacement options.
Sample Compatibility & Compliance
The PHB-2 is validated for use with aqueous liquid samples across standard laboratory, wastewater, aquaculture, food processing, and classroom environments. It is not intended for non-aqueous, viscous, or highly proteinaceous media without appropriate electrode selection and cleaning protocols. All supplied buffer solutions (pH 4.00, 6.86, and 9.18) conform to NIST-traceable composition standards and are certified for two-point calibration per ISO 7888 and USP . While the device itself does not include GLP-compliant audit trail functionality, its calibration procedure—documented via user-maintained logbooks—supports adherence to basic GMP and ISO/IEC 17025 traceability requirements when used within defined SOPs. The instrument complies with IEC 61010-1 safety standards for electrical equipment for measurement, control, and laboratory use.
Software & Data Management
The PHB-2 operates as a standalone analog-digital converter with no embedded software, firmware update capability, or data logging function. Measurement values are displayed directly on a clear LCD screen and must be manually recorded. This design eliminates firmware dependency, reduces validation burden, and enhances long-term reliability in resource-constrained or regulated environments where software qualification is impractical. For laboratories requiring electronic data capture, the meter can be paired with external digital recorders or USB-based data acquisition interfaces via analog output adapters (sold separately). Calibration history, electrode performance metrics, and environmental conditions are maintained externally in accordance with institutional documentation policies.
Applications
- Academic instruction: Demonstrating acid-base equilibria, titration endpoints, and electrode theory in undergraduate chemistry and biology labs.
- Environmental monitoring: On-site pH assessment of surface water, groundwater, effluent streams, and soil leachates during field surveys.
- Food and beverage QC: Rapid verification of rinse water, brine solutions, and product contact surfaces per HACCP prerequisite programs.
- Aquaculture and hydroponics: Daily monitoring of tank and reservoir pH to maintain optimal growth conditions for aquatic species and plants.
- Pharmaceutical pre-formulation: Preliminary pH screening of excipient solutions and buffer compatibility studies prior to analytical method development.
FAQ
What calibration standards are included with the PHB-2?
The instrument ships with three 50 mL bottles of NIST-traceable calibration buffers: pH 4.00, pH 6.86, and pH 9.18.
Is automatic temperature compensation (ATC) supported?
No—the PHB-2 uses manual temperature compensation; users enter the measured sample temperature using the provided glass thermometer.
Which electrodes are compatible with the PHB-2?
All SANXIN BNC-output composite electrodes, including the 201-C (general-purpose), 206-C (narrow-neck vessels), and 2015P-C (surface/micro-volume), are fully compatible.
Can the PHB-2 be used for non-aqueous samples?
It is not recommended for organic solvents or low-dielectric media without electrode modification and procedural validation due to unstable junction potentials and reference drift.
Does the device comply with FDA 21 CFR Part 11?
No—this is an analog-display instrument without electronic records, signature capability, or audit trail functionality; it is intended for non-critical or non-GxP-limited applications.
