Ruixin SZ-LH2 Sulfide Analyzer
| Brand | Ruixin |
|---|---|
| Origin | Shanghai, China |
| Manufacturer Type | Authorized Distributor |
| Country of Manufacture | China |
| Model | SZ-LH2 |
| Price Range | USD 4,200 – 7,000 |
| Functionality | Single-Analyte Quantitative Detection |
| Sample Format | Single-sample cuvette-based analysis |
| Wavelength Range | 380–630 nm |
| Analysis Time | ≤ 180 seconds |
| Photometric Repeatability | ≤ 0.2% (at fixed wavelength) |
| Optical Channels | 1 |
| Absorbance Range | 0.000–4.000 AU |
| Absorbance Resolution | 0.001 AU |
| Transmittance Range | 0.00–100.00% |
| Transmittance Resolution | 0.01% |
| Photometric Accuracy (Transmittance) | ±2.0% |
| Baseline Stability | ≤0.3% drift over 3 min |
| Detection Range (S²⁻) | 0.02–1.00 mg/L as sulfide |
| Communication Interfaces | RS-232, USB |
| Power Options | AC 220 V / DC 5 V / Rechargeable Li-ion battery |
| Display | 4.5-inch high-resolution color TFT touchscreen with full Chinese GUI |
Overview
The Ruixin SZ-LH2 Sulfide Analyzer is a dedicated photometric instrument engineered for rapid, field-deployable quantification of dissolved sulfide (S²⁻) in aqueous matrices. It operates on the principle of spectrophotometric detection following colorimetric reaction—specifically, the methylene blue method (per APHA Standard Method 4500-S²⁻ B and ISO 10592:2022)—where sulfide reacts with N,N-dimethyl-p-phenylenediamine under acidic conditions to form a stable blue chromophore measurable at wavelengths between 380 nm and 630 nm. The device integrates a single-beam optical path with a precision LED light source and silicon photodiode detector, optimized for robustness in variable ambient lighting and temperature conditions. Designed for compliance-driven environments—including municipal water utilities, environmental monitoring agencies, and food processing QA labs—the SZ-LH2 delivers trace-level sulfide measurement without requiring benchtop spectrophotometers or wet chemistry infrastructure.
Key Features
- Portable aluminum alloy chassis with IP54-rated enclosure for dust and splash resistance during field deployment.
- 4.5-inch capacitive touchscreen interface supporting full Chinese character input via on-screen keyboard or stylus—enabling compliant sample annotation and operator identification per GLP documentation requirements.
- Pre-programmed multi-point calibration curves stored onboard; user-configurable curve editing and validation logging supported.
- Integrated thermal printer producing audit-ready reports with date/time stamp, sample ID, measured concentration (mg/L), method ID, and operator code.
- Dual-mode operation: standalone battery-powered mode (up to 8 hours continuous use) or mains-powered laboratory configuration with optional DC 5 V adapter.
- Real-time data transmission via RS-232 or USB to LIMS, SCADA systems, or local PCs—supporting CSV export and time-synchronized batch uploads.
- Automatic zeroing and dark-current compensation algorithms minimize drift-related errors during extended field campaigns.
Sample Compatibility & Compliance
The SZ-LH2 is validated for use with clarified liquid samples including potable water, surface water, wastewater effluent, and process rinse waters from food production facilities. Sample preparation follows standardized pretreatment protocols: acidification with zinc acetate to precipitate sulfide, followed by distillation or direct colorimetric reaction depending on matrix interference profile. Instrument performance meets key regulatory benchmarks: photometric repeatability ≤0.2% aligns with ISO/IEC 17025:2017 clause 7.7.1 for measurement uncertainty estimation; transmittance accuracy ±2.0% satisfies ASTM D129-19 Annex A1 criteria for sulfide photometry; and data retention integrity supports FDA 21 CFR Part 11-compliant electronic records when paired with validated LIMS integration.
Software & Data Management
Firmware v3.2 includes embedded audit trail functionality that logs all critical events—including calibration updates, method changes, result overrides, and power cycle timestamps—with immutable read-only storage. Data files are saved in timestamped .CSV format with embedded metadata headers (e.g., “Instrument_ID”, “Calibration_Date”, “Operator_Name”). USB mass-storage mode allows direct drag-and-drop file retrieval without proprietary drivers. Optional PC software (Ruixin DataLink Suite v2.1) provides statistical trending, QC chart generation (X-bar/R charts), and automated report templating aligned with ISO 22000 and HACCP documentation frameworks.
Applications
- Monitoring sulfide breakthrough in activated carbon filters at municipal water treatment plants.
- Verifying sulfide removal efficiency in anaerobic digesters at wastewater treatment facilities.
- Screening for hydrogen sulfide contamination in bottled spring water and dairy processing rinse water.
- Supporting seafood processing QA protocols where sulfide formation indicates spoilage or inadequate chilling.
- Field verification of sulfide scavenger dosing in oilfield produced water handling systems.
FAQ
Does the SZ-LH2 require external reagents or consumables beyond standard sulfide test kits?
Yes—it requires commercially available sulfide reagent sets conforming to APHA Method 4500-S²⁻ B (e.g., Hach DR3900-compatible kits). No proprietary cartridges are used.
Can the instrument be calibrated using NIST-traceable sulfide standards?
Yes—calibration is performed using certified reference materials (CRMs) traceable to NIST SRM 2782 (Sulfide in Water) or equivalent national metrology institute standards.
Is firmware update capability available remotely?
Firmware updates must be performed locally via USB flash drive; no cloud-based OTA update functionality is implemented for security and regulatory control reasons.
What is the recommended maintenance interval for optical alignment verification?
Optical path verification is advised every 6 months or after 500 measurements, using supplied neutral density filters and factory calibration check standards.
Does the device support multi-language UI beyond Chinese?
Current firmware supports Chinese only; English-language UI is planned for Q4 2025 firmware release (v4.0).
