AQUASEARCHER™ AB23PH Benchtop pH/ORP/Temperature Meter
| Brand | OHAUS |
|---|---|
| Origin | Jiangsu, China |
| Manufacturer Type | Direct Manufacturer |
| Regional Classification | Domestic (China) |
| Model | AB23PH-B |
| Instrument Type | Benchtop |
| Parameter Type | Single-Parameter (pH), Dual-Mode (pH/ORP) |
| Measurement Accuracy | ±0.01 pH |
| pH Range | 0.00 – 14.00 |
| Resolution | 0.01 pH / 1 mV / 0.1 °C |
| Calibration | Auto-buffer recognition, 2-/3-point calibration |
| Data Storage | 99 readings |
| Display | 5-inch segmented backlit LCD |
| Power | AC adapter |
| Housing | ABS plastic with membrane mechanical keypad |
Overview
The AQUASEARCHER™ AB23PH is a precision benchtop electrochemical meter engineered for routine pH, oxidation-reduction potential (ORP), and temperature measurement in quality control laboratories, academic teaching labs, and industrial process support environments. It operates on the fundamental principle of potentiometric measurement: pH is determined by the Nernst equation-derived voltage difference between a pH-sensitive glass electrode and a stable reference electrode, while ORP reflects the net redox activity of a solution relative to a standard hydrogen electrode (SHE). Temperature compensation is applied automatically using an integrated thermistor sensor, ensuring thermally corrected readings across 0–100 °C. Designed for operational simplicity without compromising metrological integrity, the AB23PH delivers traceable, repeatable results aligned with ISO 8655, ASTM E70, and USP guidelines for pH measurement validation.
Key Features
- 5-inch segmented backlit LCD display with high-contrast digit rendering—optimized for ambient light variability and extended visual fatigue reduction during multi-hour testing sessions.
- Intuitive membrane keypad with six labeled tactile buttons—enabling one-hand operation and minimizing accidental input errors in wet or gloved-lab conditions.
- Auto-buffer recognition for standard pH 4.01, 7.00, and 10.01 buffers (CN-version compliant)—reducing calibration time and eliminating manual buffer selection errors.
- Configurable 2-point or 3-point calibration protocol with real-time slope and offset diagnostics—supporting GLP-compliant documentation of calibration validity (e.g., ≥95% slope, ≤35 mV offset).
- Integrated electrode holder molded into the ABS chassis—providing mechanical stability during immersion and enabling compact footprint placement (51 × 210 × 142 mm) on crowded benchtops.
- Non-volatile memory storing up to 99 sequential measurements—including timestamped pH, mV, and °C values—with manual recall and review capability (no export interface).
Sample Compatibility & Compliance
The AB23PH is compatible with all standard BNC-input combination pH/ORP electrodes (not supplied), including gel-filled, refillable, and double-junction configurations. It supports aqueous samples across the full pH range (0.00–14.00), non-aqueous media (with appropriate electrode selection and correction), and redox-active solutions such as disinfectant residuals, electroplating baths, and fermentation broths. The instrument meets CE marking requirements for electromagnetic compatibility (EN 61326-1) and safety (EN 61010-1). Its calibration logic and accuracy specification (±0.01 pH at 25 °C) align with ISO/IEC 17025 technical competency criteria for pH testing in accredited laboratories. While not FDA 21 CFR Part 11–enabled due to absence of electronic signature or audit trail functionality, it satisfies basic GMP/GLP data recording expectations when used with handwritten logbooks.
Software & Data Management
The AB23PH operates as a standalone instrument with no embedded firmware update capability or PC connectivity (no USB, Bluetooth, or RS-232 interfaces). All configuration and calibration settings are retained in non-volatile memory during power cycling. Data storage is limited to on-device numeric recall—99 entries with no metadata tagging, sorting, or export options. For regulated environments requiring electronic records, users must manually transcribe readings into LIMS or Excel-based templates. The absence of digital output necessitates adherence to paper-based SOPs for data integrity, including dual-operator verification and dated signature fields per ISO 15197 or CLIA standards where applicable.
Applications
- Quality assurance of purified water and WFI (Water for Injection) in pharmaceutical manufacturing—verifying compliance with EP 2.2.3 and USP .
- pH monitoring of nutrient media and bioreactor harvest streams in bioprocess development.
- Environmental testing of wastewater effluent, soil extracts, and surface water per EPA Method 150.1.
- Food and beverage QC—measuring acidity in dairy products, juices, and fermented foods per AOAC 973.41.
- Academic instruction in general chemistry and analytical lab courses—demonstrating Nernstian behavior, calibration drift, and junction potential effects.
FAQ
Does the AB23PH include a pH electrode?
No—the instrument does not ship with any electrode. Users must procure a compatible BNC-input pH or ORP electrode separately.
Is temperature compensation automatic or manual?
Automatic—integrated thermistor provides real-time temperature sensing and applies NIST-traceable algorithms for pH compensation.
Can the AB23PH be used with non-standard calibration buffers?
No—auto-buffer recognition is restricted to the three pre-programmed Chinese national standard buffers (pH 4.01, 7.00, 10.01); custom buffer values cannot be entered.
What is the operating temperature range for the instrument itself?
10–40 °C ambient, with ≤80% non-condensing relative humidity—consistent with Class II laboratory environmental specifications.
Is the device suitable for continuous immersion or in-line process use?
No—it is strictly a benchtop, intermittent-use instrument; no IP rating or process-tube mounting provisions are provided.
