WTW Turb 550T and Turb 550IR Laboratory Turbidimeters

Overview

The WTW Turb 550T and Turb 550IR are high-precision laboratory turbidimeters engineered for reliable, traceable, and compliant measurement of turbidity in aqueous samples across environmental, municipal, pharmaceutical, and industrial quality control laboratories. Both instruments operate on the nephelometric principle—measuring light scattered at a 90° angle relative to the incident beam—ensuring alignment with internationally recognized optical detection methodologies. The Turb 550T employs a tungsten lamp source optimized for broad-spectrum visible-light scattering, meeting the spectral and procedural requirements of US EPA Method 180.1 for drinking water and wastewater analysis. In contrast, the Turb 550IR utilizes an 860 nm infrared LED, eliminating interference from sample coloration and enabling robust performance in yellow- or brown-tinted matrices such as surface waters, treated effluents, and process streams—fully conforming to DIN 27027 and ISO 7027 standards. With a dynamic measurement range spanning 0.01 to 1000 NTU (Nephelometric Turbidity Units) or FNU (Formazin Nephelometric Units), both models support quantification from ultrapure water (e.g., deionized water at ~0.02 NTU) through highly turbid industrial effluents (up to 2000 NTU when using optional dilution protocols). Their compact benchtop architecture, integrated GLP functionality, and dual calibration capability make them suitable for routine QC workflows requiring audit-ready documentation and method reproducibility.

Key Features

• True 90° nephelometric detection geometry per ISO 7027 and US EPA 180.1 specifications
• Auto-ranging optics with three resolution tiers: 0.01 NTU (0.01–9.99), 0.1 NTU (10.0–99.9), and 1 NTU (100–1000)
• Automatic 1-, 2-, or 3-point calibration using certified AMCO® standard suspensions (0.02, 10.0, and 1000 NTU)
• GLP-compliant data logging including date/time stamps, operator ID, calibration history, and measurement metadata
• RS-232 serial interface for direct connection to PCs or printers; compatible with WTW’s LabX software suite for automated report generation
• Optional flow-through cell accessory enables unattended sequential analysis without manual vial rinsing—ideal for batch testing or process monitoring integration
• Dual power options: AC adapter (100–240 VAC) with internal 3 V CR3032 lithium backup battery (3-year service life)
• Robust housing with IP20-rated enclosure; operating temperature range of +10 to +40 °C ensures stability in standard lab environments

Sample Compatibility & Compliance

The Turb 550 series accommodates standard 25-mm round glass cuvettes (included), supporting transparent to moderately opaque liquid samples—including potable water, groundwater, wastewater, boiler feedwater, and pulp-and-paper white water. Its optical design minimizes errors induced by dissolved color, air bubbles, or particulate settling—particularly enhanced in the Turb 550IR via infrared illumination. Regulatory alignment is embedded into system architecture: Turb 550IR satisfies DIN 27027 and ISO 7027 for metrological equivalence in European and global accreditation frameworks, while Turb 550T fulfills US EPA Method 180.1 requirements for regulatory reporting in U.S. public water systems. Both units support full GLP documentation, including electronic audit trails for calibration events, user actions, and raw data export—facilitating readiness for ISO/IEC 17025, FDA 21 CFR Part 11 (when used with compliant software), and EU GMP Annex 11 assessments.

Software & Data Management

Data acquisition and traceability are managed via native instrument firmware with timestamped storage of up to 1,000 measurements and full calibration logs. When interfaced with a PC via RS-232 (using AK Labor cable), the turbidimeters integrate seamlessly with WTW’s LabX software—enabling automated data capture, statistical evaluation (mean, SD, CV%), customizable report templates (PDF/CSV), and secure user access control. All exported files retain embedded metadata required for laboratory accreditation audits. Instrument settings—including units (NTU/FNU), auto-zero delay, and alarm thresholds—are configurable and retained across power cycles. No proprietary drivers are required; standard Windows COM port configuration suffices for plug-and-play operation.

Applications

• Drinking water compliance testing per WHO, EPA, and EU Drinking Water Directive
• Wastewater treatment plant effluent monitoring (primary, secondary, and tertiary stages)
• Pharmaceutical water system validation (PW, WFI) under USP and EP 2.2.2
• Food & beverage process control (e.g., juice clarification, beer filtration, dairy homogenization verification)
• Environmental field lab analysis of river, lake, and reservoir samples
• Research applications involving colloidal stability, coagulation-flocculation kinetics, and membrane fouling studies

FAQ

What is the difference between Turb 550T and Turb 550IR?
The Turb 550T uses a tungsten lamp and complies with US EPA Method 180.1; the Turb 550IR uses an 860 nm infrared LED and complies with ISO 7027/DIN 27027—making it less sensitive to sample color interference.
Can I use the same calibration standards for both models?
Yes—both accept the same AMCO® primary standards (0.02, 10.0, and 1000 NTU), ensuring cross-platform comparability and method transferability.
Is a flow cell included in the standard configuration?
No—the flow-through cell is an optional accessory (order separately); standard delivery includes two matched glass cuvettes and a 3-point calibration kit.
Does the instrument meet FDA 21 CFR Part 11 requirements?
The hardware supports ALCOA+ data integrity principles; full Part 11 compliance requires implementation of validated software (e.g., LabX with electronic signatures and audit trail activation) and documented SOPs.
How often does the light source require replacement?
The tungsten lamp (Turb 550T) has a rated lifetime of >2,000 hours; the IR LED (Turb 550IR) is rated for >50,000 hours—effectively maintenance-free over typical laboratory service intervals.