904 Titrando

Importance of the topic

The ability to perform reliable, highly accurate titrations is a cornerstone of modern analytical chemistry. Automated titrators reduce operator error, increase sample throughput, and ensure consistent data quality for research laboratories, quality control in industry, and regulated environments. The Metrohm 904 Titrando system exemplifies these advances by combining modular hardware and flexible software control to meet diverse titration requirements.

Study objectives and overview

This document introduces the design, operation, and maintenance of the 904 Titrando titrator. Key goals are to explain how to integrate the instrument with peripheral devices, configure titration methods, ensure laboratory safety, and troubleshoot common issues. The manual covers hardware descriptions, software interfaces, titration modes, installation procedures, and technical specifications.

Methodology and instrumentation

The 904 Titrando is operated either via a Metrohm Touch Control unit (stand‐alone mode) or through PC‐based software (e.g., tiamo). It features:

• One or two galvanically isolated measuring interfaces for potentiometric (pH, ion, metal), amperometric/voltametric, and temperature measurements.
• An internal exchange‐unit dosing drive supporting cylinder volumes from 1 to 50 mL with 20 000‐step resolution.
• Four MSB (Metrohm Serial Bus) ports to connect dosing devices (Dosino, Dosimat), magnetic stirrers, titration stands, and Remote Boxes for external control signals.
• Two USB downstream ports for printers, barcode readers, keyboards, and hubs, plus a USB upstream “Controller” port to link the Touch Control or PC.
• Electrode connectors for separate reference, polarizable, and iTrode sensors.

Detailed installation steps cover mechanical setup, power connection, driver installation, and device configuration. Titration vessel setup emphasizes optimal stirring and electrode positioning.

Main results and discussion

The system supports dynamic and monotonic equivalence point titrations (DET, MET), single/multi‐endpoint modes (SET), concentration determinations (including standard addition), and electrode calibration. Automated dosing commands (PREP, EMPTY, ADD, LQH) ensure reproducible fluid handling. Built‐in diagnostics monitor exchange‐unit status and error conditions. Comprehensive safety guidelines address electrical, chemical, and ergonomic considerations.

Benefits and practical applications of the method

The Metrohm 904 Titrando offers:

• Modular flexibility—mix and match dosing units, stirrers, and sensors.
• High precision—fine‐tuned dosing rates, sub‐millivolt/pH resolution.
• Scalability—single‐standalone or multi‐instrument network via USB/MSB.
• Traceability—data storage on exchange‐unit chips and software logs.
• Ease of use—intuitive Touch Control interface or advanced PC software.

Typical applications include acidity/alkalinity determination, complexometric titrations, Karl Fischer water content analysis, and ion‐selective assays.

Future trends and possibilities

Emerging directions for titration technology include integration with laboratory information management systems (LIMS), enhanced remote monitoring via IoT connectivity, AI‐driven method optimization, and smart sensors with real‐time diagnostics. Advanced microfluidic dispensing and optical end‐point detection may expand the range of analytical applications.

Conclusion

The Metrohm 904 Titrando combines robust hardware, versatile software control, and comprehensive peripheral support to meet the demanding needs of modern analytical laboratories. Its modular design, precise measurement capabilities, and user‐friendly operation underscore its role as a reliable platform for a wide range of titration methods.

References

Metrohm AG. 904 Titrando Manual, document number 8.904.8003EN, January 2022.