Alalis MP6500 Multi-Parameter Benchtop Conductivity & Dissolved Oxygen Meter
| Brand | Alalis |
|---|---|
| Origin | Shanghai, China |
| Model | MP6500 |
| Instrument Type | Laboratory Benchtop |
| Measurement Principle | Electrochemical Clark-type Polarographic Sensor |
| DO Range | 0–20.00 mg/L |
| DO Accuracy | ±0.30 mg/L |
| DO Repeatability | 0.1% |
| Detection Limit | 0.10 mg/L |
| Temperature Compensation | 0–45 °C (auto), Salinity Compensation: 0–45 ppt (auto), Barometric Pressure Compensation: 80–105 kPa (manual) |
| Data Storage | 1000 sets (manual & auto) |
| Interface | USB |
| IP Rating | IP54 |
| Display | 90 × 68 mm LCD with white backlight and real-time clock |
Overview
The Alalis MP6500 is a rigorously engineered multi-parameter benchtop analyzer designed for comprehensive water quality assessment in regulated laboratory environments. It integrates four core electrochemical measurement modalities—pH, conductivity, ion concentration (ISE), and dissolved oxygen (DO)—into a single platform compliant with GLP (Good Laboratory Practice) data integrity requirements. The DO module employs a Clark-type polarographic sensor with a replaceable membrane cap and electrolyte-filled cathode/anode configuration, enabling stable amperometric detection of molecular oxygen diffusing through a selective Teflon membrane. This principle ensures high specificity for O₂ in aqueous matrices without interference from redox-active species commonly found in wastewater, aquaculture effluents, or natural surface waters. The instrument’s architecture supports traceable calibration workflows, audit-ready data logging, and temperature-, salinity-, and barometric pressure-compensated DO quantification—critical for accurate reporting under ASTM D888, ISO 5814, and EPA Method 360.5.
Key Features
- Simultaneous measurement of pH, conductivity, ion activity (pX), and dissolved oxygen in a unified interface with context-aware parameter switching.
- Advanced calibration logic: pH auto-calibration (1–5 points) using CH, USA, or NIST traceable buffers; conductivity (1–4 points) with dual-series standards; ISE (2–5 points) with customizable slope validation.
- Comprehensive temperature compensation: pH (0–100.0 °C, auto/manual), ISE (0–60.0 °C), conductivity (0–50.0 °C), and DO (0–45.0 °C) with configurable reference temperatures and linear/non-linear coefficients.
- Dedicated high-purity water modes: low-conductivity measurement with cell constant selection (K = 1.0 cm⁻¹), ammonia-compensated pH for power plant feedwater analysis, and resistivity/TDS/salinity calculation per ISO 7888 and ASTM D1125.
- Polarographic DO sensor with integrated thermistor and salinity sensor; 3–5 min polarization time; factory-preconditioned membrane cap; automatic air-saturation calibration via included calibration sleeve.
- GLP-compliant data management: timestamped storage of 1000 measurement records (including calibration logs, electrode diagnostics, and environmental metadata); USB export to CSV-compatible formats.
- Robust mechanical design: IP54-rated enclosure with sealed electrode ports, rubberized protective caps, and ergonomic universal electrode stand for reproducible probe positioning.
Sample Compatibility & Compliance
The MP6500 is validated for use across diverse aqueous sample types including freshwater, seawater, wastewater effluent, process water, fermentation broths, and pharmaceutical-grade purified water. Its DO sensor meets the operational specifications defined in ISO 5814 for polarographic oxygen measurement and aligns with the performance criteria of USP for dissolved oxygen in purified water. Conductivity measurements adhere to ASTM D1125 and ISO 7888 for electrical conductivity determination in water. All calibration protocols support traceability to national metrological standards, and the instrument’s data structure—including user ID, calibration timestamps, electrode serial numbers, and environmental parameters—enables full compliance with FDA 21 CFR Part 11 when paired with validated software workflows. The system is routinely deployed in environmental monitoring labs accredited to ISO/IEC 17025 and municipal water quality control facilities operating under EU Directive 2000/60/EC.
Software & Data Management
The MP6500 includes PC-based communication software delivered on optical media, supporting bidirectional data transfer via USB virtual COM port. Raw datasets include measured values, associated uncertainties, calibration history, sensor status flags (e.g., membrane integrity, electrolyte level), and ambient conditions (temperature, salinity, pressure). Exported files conform to UTF-8 encoded CSV format with header rows compliant with LIMS ingestion standards. Audit trail functionality records all user-initiated actions—including parameter changes, calibration events, and data deletions—with immutable timestamps and operator identifiers. Data encryption is not embedded in firmware; however, file-level security may be applied externally per organizational IT policy. The instrument does not support cloud synchronization or remote access, preserving data sovereignty in on-premise analytical workflows.
Applications
- Environmental monitoring: DO profiling in lakes, rivers, estuaries, and coastal zones per EPA Region 10 protocols; long-term trend analysis of hypoxia events.
- Wastewater treatment: Aeration basin optimization, activated sludge respiration rate monitoring, and effluent compliance verification against discharge permits (e.g., NPDES).
- Aquaculture and fisheries: Real-time DO surveillance in recirculating aquaculture systems (RAS) to prevent hypoxic stress in finfish and shellfish.
- Pharmaceutical water systems: Monitoring of purified water (PW) and water for injection (WFI) per USP , including temperature-corrected DO thresholds at 25 °C.
- Research laboratories: Kinetic studies of aerobic biodegradation, microbial fuel cell characterization, and corrosion inhibitor efficacy testing in cooling water circuits.
FAQ
What calibration standards are supported for dissolved oxygen measurement?
The MP6500 uses air-saturation calibration at ambient pressure and temperature, executed automatically via the supplied calibration sleeve. No liquid standards are required for DO; however, users must manually input local barometric pressure (80–105 kPa) for accurate mg/L conversion.
Does the instrument support automatic recognition of conductivity cell constants?
No—the user must manually select the appropriate cell constant (e.g., K = 1.0 cm⁻¹) during setup. The device does not feature RFID or digital encoding in electrodes.
Can the DO sensor be used in high-salinity seawater (>35 ppt)?
Yes—the built-in salinity compensation covers 0–45 ppt, enabling reliable DO quantification across marine, brackish, and hypersaline environments per ISO 5814 Annex B.
Is the USB interface compatible with modern Windows and macOS versions?
The included software is certified for Windows 7–11 (64-bit) and macOS 10.15–14.x. Driver installation requires administrator privileges; no additional hardware dongles are needed.
How is data integrity ensured during power interruption?
All measurements and calibrations are written to non-volatile memory immediately upon confirmation. Power loss during active measurement may result in incomplete record entry, but previously stored data remains fully retained.
