Leici PHS-3C Benchtop pH Meter

Overview

The Leici PHS-3C is a precision benchtop pH meter engineered for routine laboratory pH and redox potential (mV) measurements in quality control, environmental monitoring, educational laboratories, and industrial process support. Based on potentiometric measurement principles, the instrument determines hydrogen ion activity via a glass pH electrode and reference junction, converting the resulting electromotive force (EMF) into a calibrated pH or millivolt reading. Its 0.01-class accuracy—per Chinese national metrological standard JJG 119—ensures traceable performance suitable for applications requiring compliance with ISO/IEC 17025–accredited testing procedures. Designed for stability and operational simplicity, the PHS-3C employs a robust analog-to-digital conversion architecture with low-drift circuitry to minimize thermal drift and noise interference during extended use.

Key Features

• High-contrast LCD display with backlight-independent character clarity, optimized for ambient lab lighting conditions
• Dual-parameter capability: simultaneous pH and mV measurement with independent range selection and unit toggling
• Intelligent endpoint detection algorithm that adapts to electrode response kinetics, supporting both equilibrium (stable-signal) and continuous (real-time trend) measurement modes
• Manual temperature compensation (MTC) with direct input via numeric keypad; compatible with standard Pt1000 or thermistor-based temperature probes (optional)
• Three-point calibration routine with automatic recognition of GB-standard buffer solutions (pH 4.00, 6.86, 9.18), reducing operator error and standardization time
• IP54-rated enclosure providing protection against dust ingress and water splashes—suitable for shared lab benches and teaching environments
• Built-in power management: auto-shutdown after 10 minutes of inactivity; non-volatile memory preserves calibration data and settings during power interruption

Sample Compatibility & Compliance

The PHS-3C is validated for aqueous and mildly buffered solutions across a broad pH spectrum (−2.00 to 18.00), including acidic digestates, alkaline cleaning agents, and hydrolyzed biological samples. It supports standard combination pH electrodes with BNC connectors and double-junction reference systems—enabling reliable measurements in samples containing sulfides, proteins, or low-ionic-strength matrices. While not certified to IEC 61000-4 electromagnetic immunity standards out-of-the-box, its analog front-end design demonstrates stable operation in typical Class II laboratory electromagnetic environments. The instrument meets GB/T 11165–2022 requirements for laboratory pH meters and is compatible with GLP documentation workflows when used with external audit-trail-enabled data logging software.

Software & Data Management

Data handling is performed locally via integrated flash memory supporting up to 50 measurement records, each timestamped and tagged with pH/mV values, temperature, calibration status, and electrode ID (if entered manually). Records can be reviewed, navigated by index, or selectively erased without resetting system configuration. Though the PHS-3C lacks USB or RS-232 connectivity, its structured data format enables manual transcription into LIMS or Excel-based QA/QC spreadsheets. For regulated environments, users may pair the meter with third-party GLP-compliant data acquisition tools using analog mV output (available via optional interface module) to satisfy FDA 21 CFR Part 11 requirements for electronic records and signatures.

Applications

• Academic instruction: pH titration curve generation, buffer capacity analysis, and electrode response characterization in undergraduate chemistry labs
• Environmental testing: soil extract pH, wastewater effluent monitoring, and surface water alkalinity profiling per EPA Method 150.1
• Food & beverage QC: acidity verification in dairy products, fruit juices, and fermented goods according to AOAC 973.41
• Pharmaceutical manufacturing: excipient slurry pH checks during wet granulation and final product release testing aligned with USP
• Industrial maintenance: cooling tower water pH surveillance, boiler feedwater alkalinity control, and electroplating bath monitoring

FAQ

Does the PHS-3C support automatic temperature compensation (ATC)?

No—it provides manual temperature compensation only. Users must enter the sample temperature value prior to measurement.
Can custom buffer solutions be programmed into the meter?

Yes—the device allows entry of user-defined buffer pH values for calibration outside the three preloaded GB standards.
Is the included composite electrode refillable or serviceable?

The standard supplied electrode features a gel-filled, maintenance-free reference system; however, replacement electrolyte cartridges and glass membranes are available as consumables.
What is the recommended recalibration frequency under routine use?

Per ISO 8655-5 guidelines, recalibration is advised before each analytical session or every 2 hours during continuous operation—whichever occurs first.
Does the instrument meet international regulatory requirements for GMP environments?

While the hardware itself does not include 21 CFR Part 11–compliant audit trails, its measurement repeatability (±0.01 pH) and documented calibration traceability support integration into GMP-aligned SOPs when paired with validated procedural controls.