Yoke SZ-180 Touchscreen Colorimeter (Basic Model)

Overview

The Yoke SZ-180 Touchscreen Colorimeter (Basic Model) is a dedicated optical measurement instrument engineered for precise, repeatable color quantification in aqueous samples according to the internationally recognized Platinum-Cobalt (Pt-Co) standard method. Designed for routine water quality laboratories, municipal wastewater facilities, and environmental monitoring centers, the SZ-180 operates on the principle of absorbance-based photometric comparison against a calibrated Pt-Co reference scale—expressed in Platinum-Cobalt Units (PCU). Its optical architecture integrates a thermally stable cold LED light source coupled with a precision narrow-band interference filter system, minimizing spectral drift and ensuring high photometric reproducibility across extended operational cycles. Unlike broad-spectrum or unfiltered colorimeters, the SZ-180’s optical path is optimized specifically for the 455 nm nominal wavelength region defined in GB 11903–1989, enabling direct compliance with Chinese national standard methodology without interpolation or algorithmic correction.

Key Features

• 5.6-inch high-resolution color touchscreen interface with intuitive GUI navigation—designed for rapid method selection, real-time data visualization, and touch-responsive calibration workflows.
• Dedicated Pt-Co color measurement channel with linear dynamic range from 0 to 500 PCU, validated per GB 11903–1989 requirements for turbidity-free, filtered water samples.
• Robust optical subsystem featuring long-life cold LED illumination (rated >100,000 hours) and temperature-compensated narrow-band interference filtering for minimal inter-lot variability and reduced recalibration frequency.
• ARM9-based embedded processing platform with 512 MB internal memory—supporting fast boot times, multi-step protocol execution, and real-time background data logging.
• Expandable calibration framework: preloaded with 5 factory-certified Pt-Co curves and 195 user-configurable curve slots; supports custom K-factor segmentation for non-linear ranges or matrix-matched standards.
• Dual communication interfaces—USB 2.0 host/device mode and RS-232 serial port—for seamless integration with LIMS, external PCs, or automated data aggregation servers.
• Optional thermal printer module enables on-demand hardcopy output of current measurements, historical datasets, or calibration reports—fully traceable with timestamp and operator ID fields.

Sample Compatibility & Compliance

The SZ-180 is intended for use with clarified, particle-free aqueous samples prepared per GB 11903–1989 specifications—typically involving vacuum filtration through 0.45 µm membrane filters prior to analysis. It is not suitable for emulsions, suspensions, or highly absorbing organic matrices without prior dilution or pretreatment. Instrument validation aligns with ISO/IEC 17025:2017 clause 5.9 (method validation) and supports GLP-compliant documentation when paired with audit-trail-enabled software. While the device itself does not carry CE or FDA 510(k) certification, its measurement methodology is fully traceable to national metrological standards referenced in GB/T 5750.4–2023 (Standard Methods for Examination of Drinking Water – Sensory Characteristics), and its hardware design conforms to IEC 61010-1:2010 safety requirements for laboratory electrical equipment.

Software & Data Management

Data handling is managed via an embedded Linux-based firmware environment supporting FAT32-formatted USB mass storage devices for export of CSV-formatted datasets—including sample ID, measurement time, PCU value, curve ID, operator code, and instrument serial number. Internal database retention exceeds 5,000 entries with automatic timestamping, cyclic overwrite protection, and date-range search functionality. No proprietary desktop software is required; exported files are natively compatible with Microsoft Excel, MATLAB, and common LIMS platforms. For regulated environments, the system supports manual entry of analyst initials and batch identifiers—though native 21 CFR Part 11 electronic signature or audit trail features are not implemented at the firmware level. Users deploying the SZ-180 in GMP or ISO 17025-accredited labs are advised to supplement with external procedural controls for data integrity verification.

Applications

• Drinking water treatment plants: routine monitoring of finished water color as part of disinfection byproduct precursor assessment.
• Municipal wastewater effluent reporting: compliance verification against discharge limits specified in DB11/307–2013 (Beijing Local Standard) and similar regional regulations.
• Pharmaceutical process water QC: color testing of purified water (PW) and water for injection (WFI) per USP guidance where Pt-Co equivalence is accepted.
• Environmental field laboratories: rapid screening of surface water bodies during seasonal algal bloom events or industrial runoff investigations.
• Educational laboratories: teaching core principles of photometry, standard curve development, and regulatory method adherence in undergraduate analytical chemistry curricula.

FAQ

Does the SZ-180 comply with ASTM D1209 or ISO 6271?
No—the SZ-180 implements only the Pt-Co method per GB 11903–1989. ASTM D1209 and ISO 6271 specify identical procedures but require certified reference standards traceable to NIST or BAM; users requiring those certifications must validate their own reference materials.
Can the instrument measure APHA color beyond 500 PCU?
No—its optical design and firmware are limited to 0–500 PCU. Samples exceeding this range must be diluted with deionized water and results multiplied by the dilution factor.
Is the touchscreen resistant to chemical splashes or humidity?
The front panel meets IP54 ingress protection rating—suitable for standard lab bench use but not recommended for continuous exposure to condensation or aggressive solvents.
What is the calibration interval recommendation?
Yoke recommends initial verification upon installation, followed by quarterly calibration using certified Pt-Co standards (e.g., Hach 210600 or equivalent), or after any maintenance event affecting the optical path.
Can custom calibration curves be exported or backed up externally?
Yes—curve parameters and coefficients are stored in human-readable XML format on USB drives, allowing full backup, version control, and cross-instrument deployment.