Lohan LH-P3SD Portable Colorimeter (Qinglan Series)

Overview

The Lohan LH-P3SD Portable Colorimeter (Qinglan Series) is a field-deployable, precision optical instrument engineered for rapid, reliable colorimetric analysis of water samples in compliance with national and industry-standard methodologies. It operates on the principle of absorbance photometry—measuring the attenuation of visible light at specific wavelengths as it passes through a prepared sample—to quantify color intensity as defined by platinum-cobalt (Pt-Co) or Hazen units. Designed for environmental monitoring professionals, municipal water quality technicians, and field-based research teams, the LH-P3SD delivers laboratory-grade repeatability under variable outdoor conditions. Its optical architecture incorporates stable LED light sources and precision-filtered detection pathways to minimize spectral drift and cross-sensitivity to turbidity—a critical requirement per GB 11903–1989 (Determination of Color in Water—Platinum-Cobalt Standard Method) and GB/T 5750.4–2023 (Standard Examination Methods for Drinking Water—Sensory Characteristics and Physical Parameters).

Key Features

• Optical design compliant with GB 11903–1989 and GB/T 5750.4–2023, ensuring traceability to national reference methods and minimizing operator-induced variability.
• Integrated UV-enhanced optical path reduces interference from suspended solids and colloidal turbidity, improving measurement fidelity in raw or minimally filtered water matrices.
• High-capacity rechargeable lithium-ion battery supports continuous operation for up to 8 hours under mixed-use field conditions—including repeated measurement cycles, screen illumination, and data logging.
• 3.5-inch TFT color display with analog-style dial UI enables intuitive interpretation; concentration values are displayed directly in Pt-Co/Hazen units without manual conversion.
• Preloaded with five factory-calibrated standard curves covering common application ranges; users may perform multi-point curve calibration using certified reference standards to meet academic or regulatory validation requirements.
• Onboard optical calibration function allows periodic verification and adjustment of LED output intensity, maintaining photometric stability over time and extending long-term measurement accuracy.
• Intelligent over-range detection: when sample color exceeds the instrument’s upper detection limit, the display highlights the threshold value in red and indicates saturation—preventing misinterpretation of clipped readings.

Sample Compatibility & Compliance

The LH-P3SD accepts standard 25 mm round glass or quartz cuvettes (10 mm pathlength), compatible with both clear and mildly turbid aqueous samples. It is validated for use with potable water, surface water, wastewater effluents, and treated industrial discharge streams. While not intended for highly viscous or particulate-laden slurries, optional pre-filtration (e.g., 0.45 µm membrane filtration) ensures adherence to method-defined sample preparation protocols. The device meets general requirements for portable instrumentation under ISO/IEC 17025–2017 (General Requirements for the Competence of Testing and Calibration Laboratories) and supports GLP-aligned workflows through audit-ready calibration logs and user-accessible firmware versioning.

Software & Data Management

Data acquisition and configuration are managed via embedded firmware with non-volatile memory capable of storing up to 1,000 measurement records, each timestamped and tagged with operator ID (if enabled). Export is supported via USB-C interface to CSV-formatted files compatible with LIMS integration or spreadsheet-based QA/QC review. Firmware updates are delivered via signed binary packages to ensure integrity; all calibration events—including optical verification and curve adjustments—are logged with date, time, and initiating user identifier—supporting 21 CFR Part 11–aligned record retention where local policy requires electronic signature capability.

Applications

• Routine surveillance of drinking water distribution systems for color compliance per GB 5749–2022.
• Field assessment of source water quality during emergency response or seasonal bloom events.
• Process monitoring in water treatment plants—particularly coagulation/flocculation optimization and activated carbon breakthrough detection.
• Academic field studies requiring transportable, method-validated instrumentation for comparative hydrological analysis.
• Third-party environmental auditing where portable, standards-referenced color data must be defensible in regulatory reporting.

FAQ

Does the LH-P3SD require annual third-party calibration?
No formal annual recalibration is mandated; however, optical verification using the built-in calibration function is recommended before each daily use or after exposure to extreme ambient temperature shifts.
Can the instrument measure beyond the stated upper limit?
No—the LH-P3SD implements hard upper-limit detection to prevent extrapolated or interpolated results; samples exceeding the range must be diluted and reanalyzed per GB/T 5750.4–2023 Section 8.3.
Is the device suitable for ISO 17025-accredited laboratories?
Yes, when operated within its specified environmental range (10–40 °C, ≤85% RH non-condensing) and supported by documented calibration history, measurement uncertainty budgeting, and traceable reference standards.
What cuvette types are compatible?
Standard 10 mm pathlength, 12.5 mm diameter round cuvettes made of optical glass or fused quartz; polycarbonate cuvettes are not recommended due to wavelength-dependent transmission loss.
How is firmware updated?
Via USB-C connection to a Windows or macOS host running Lohan’s certified Configuration Utility v2.1+, which validates digital signatures prior to installation.