Leichi WZB-172 Portable Turbidimeter

Overview

The Leichi WZB-172 Portable Turbidimeter is an ISO 7027-compliant optical instrument engineered for field-deployable and routine laboratory turbidity measurement in water quality monitoring applications. It employs a stable 860 nm infrared LED light source and implements dual optical detection modes—nephelometric (90° scattered light) and combined scatter-transmission—to ensure reliable quantification of suspended particulate matter across diverse sample matrices. Designed in accordance with China’s HJ 1075-2019 standard for drinking water and environmental water analysis, the WZB-172 delivers traceable, repeatable results under variable ambient conditions. Its compact form factor, integrated battery management system, and IP65-rated enclosure enable robust operation in wastewater treatment plants, municipal water distribution networks, aquaculture facilities, and environmental field surveys where portability, durability, and regulatory alignment are essential.

Key Features

• 3.5-inch high-resolution color LCD display with intuitive icon-based navigation and real-time graphical feedback
• Dual-mode optical measurement: selectable nephelometric (90° scattering) or scatter-transmission ratio mode to minimize interference from colored or highly absorbing samples
• Auto-ranging capability across three dynamic ranges: 0.00–9.99 NTU (0.01 NTU resolution), 10.0–99.9 NTU (0.1 NTU resolution), and 100–500 NTU (1 NTU resolution)
• Multi-unit support: direct switching between NTU (Nephelometric Turbidity Units), FNU (Formazin Nephelometric Units), and EBC (European Brewery Convention units) without recalibration
• GLP-compliant data handling: timestamped storage of 1000 measurement records with operator ID tagging, audit trail metadata, and export-ready formatting
• Zero-point drift compensation and automatic zero correction function to maintain baseline integrity during extended field use
• Four-point calibration protocol (2, 20, 200, 500 NTU) using certified formazin or equivalent stable standards; includes factory-default calibration curve restoration
• Micro-USB interface for bidirectional communication with PC-based Leichi TurbiLink™ software (Windows/macOS compatible); supports CSV export, trend plotting, and report generation
• IP65-rated housing with shock-absorbing rubberized casing; operates continuously for >12 hours on a single charge (Li-ion battery, 3000 mAh nominal capacity)

Sample Compatibility & Compliance

The WZB-172 is validated for use with clear to moderately turbid aqueous samples—including raw surface water, filtered potable water, effluent streams, and process rinse solutions. Its 860 nm LED minimizes spectral interference from natural organic matter (NOM) and dissolved color, improving fidelity in humic-rich or algae-laden waters. The instrument meets ISO 7027:2016 requirements for instrumental performance, including linearity (R² ≥ 0.999 over full range), repeatability (≤0.5% CV at mid-range), and long-term stability (±0.5% FS/30 min). For regulated environments, it supports GLP documentation workflows through embedded data logging with immutable timestamps and user-accessible calibration history. While not FDA 21 CFR Part 11-certified out-of-the-box, its audit-ready data structure facilitates integration into validated QA/QC systems under ISO/IEC 17025 or ISO 9001 frameworks.

Software & Data Management

Leichi TurbiLink™ desktop software enables secure configuration, firmware updates, and comprehensive data review. Each stored record includes measurement value, unit, date/time stamp, calibration status flag, operator ID (if assigned), and measurement mode identifier. Export functions generate ISO-compliant CSV files suitable for LIMS ingestion or statistical analysis in JMP, Minitab, or Python/Pandas environments. The RS-232 serial output (via optional adapter) supports direct printing to industry-standard thermal printers for on-site reporting. All calibration parameters—including zero offset, gain coefficients, and multi-point curve coefficients—are retained in non-volatile memory and survive power cycling or battery replacement.

Applications

• Field verification of drinking water compliance per WHO Guidelines and China’s GB 5749-2022
• Performance monitoring of coagulation-flocculation-sedimentation units in water treatment plants
• Effluent quality control in municipal and industrial wastewater discharge points
• Process validation in pharmaceutical water systems (PW, WFI pre-checks)
• Environmental surveillance of rivers, lakes, and reservoirs under national ecological monitoring programs
• Educational laboratories requiring portable, standards-aligned turbidity instrumentation for undergraduate analytical chemistry curricula

FAQ

Does the WZB-172 require annual recalibration by an accredited lab?

No—routine user-performed calibration using the included 20/200/500 NTU standard set satisfies ISO 7027 verification requirements. External recalibration is recommended only after physical damage, sensor contamination, or deviation exceeding ±6% FS during verification checks.
Can the instrument measure samples with air bubbles or temperature gradients?

Air bubbles cause transient scattering artifacts; samples must be degassed and equilibrated to ambient temperature prior to measurement. The device does not include built-in temperature compensation, so measurements should be conducted within the specified 5–40 °C operating range.
Is the Micro-USB port used for charging only, or does it support data transfer?

It serves both functions: charging via 5 V DC input and full-speed data exchange using Leichi’s proprietary CDC-class USB virtual COM port protocol.
What happens if the battery depletes during a measurement sequence?

The device implements non-volatile memory write-on-exit: all completed measurements prior to shutdown are preserved. No data loss occurs due to unexpected power interruption.
Are replacement calibration standards available separately?

Yes—certified formazin-equivalent standards (traceable to NIST SRM 2102) are supplied as Leichi Catalog #TCS-20/200/500, with shelf life of 24 months unopened and 6 months after first use when refrigerated.