Clarity Hardware U-PAD2 A/D CONVERTER

Importance of the Topic
Chromatographic and electrochemical detector signals must be converted accurately from analog to digital form for reliable quantitative and qualitative analysis in laboratories and industrial QA/QC. High-resolution, low-noise A/D converters like U-PAD2 enable precise detection of narrow peaks, enhance signal stability, and reduce data footprint, thereby improving throughput and data integrity in modern analytical workflows.

Objectives and Study Overview
This document serves as a technical manual for the U-PAD2 24-bit Delta-Sigma A/D converter integrated with Clarity chromatography station software (ver. 2.7+). It guides users through hardware requirements, installation, configuration, use, troubleshooting, specifications, and best practices for reliable data acquisition from chromatographic detectors via USB.

Used Instrumentation

• U-PAD2 A/D Converter: external, USB-powered, dual-channel (isolated), Delta-Sigma integration
• Standard Clarity signal cable set: DET1/DET2, IN1/IN2, OUT1R/OUT2R, DB-37F connector
• Clarity Chromatography Station software version 2.7 or higher
• PC with Windows OS (32/64), free USB port

Methodology and Configuration

• Hardware installation: Install Clarity, plug U-PAD2, follow Found New Hardware Wizard, select driver from HW_DRIVERS\UPAD2.
• Signal wiring: Differential inputs (+, –, shield) for DET1/DET2; digital inputs IN1/IN2 for external Start/Stop TTL or contact closure; digital outputs OUT1/OUT2/relay contacts for autosampler sync or external control.
• Clarity System Configuration: Add Control Module “DataApex U-PAD2,” name channels, set units and synchronization, map channels to Instruments (up to four units).
• Device Setup: Edit channel names, unit conversion (mV to detector units), inversion, bipolar/unipolar ranges, digital I/O naming, supply frequency filter (50/60 Hz).
• Method Setup – Acquisition: Per-channel voltage range (156.26 mV, 1 250 mV, 12 123 mV) and sampling rate (6.25–400 sps at 50 Hz, 7.5–480 sps at 60 Hz).
• Method Setup – Measurement: External start/stop mode (Start Only, Start–Stop, Start–Restart), trigger polarity (Up/Down).

Main Results and Discussion

• Delta-Sigma integration provides continuous acquisition without input signal loss and high temperature stability.
• Noise-free resolution up to 21 bits at low sampling rates (≤25 Hz) across 3 voltage ranges; bit resolution decreases modestly at higher sampling rates.
• USB-powered design simplifies deployment, supports hot-plugging without PC restart.
• Synchronized digital inputs reduce inter-channel time lag, crucial for multi-detector peak alignment.

Benefits and Practical Applications

• High dynamic range and resolution enhance detection of both low- and high-intensity peaks.
• Flexible I/O supports synchronization with diverse autosamplers and external devices.
• Reduced data volume lowers storage and processing requirements.
• Plug-and-play USB interface speeds up setup in multi-instrument laboratories.

Future Trends and Applications

• Integration with cloud-based data management and AI-driven chromatography data analysis platforms.
• Expansion of multi-channel, networked acquisition units for remote monitoring and high-throughput screening.
• Enhanced digital filtering algorithms and real-time baseline correction through firmware updates.
• Adoption in portable or field-deployable chromatographic systems for onsite environmental and forensic analysis.

Conclusion
The U-PAD2 A/D converter, when integrated with Clarity software, delivers robust, high-resolution data acquisition for chromatographic detectors. Its Delta-Sigma architecture, flexible I/O, and user-configurable parameters optimize signal fidelity and laboratory efficiency. Proper installation, configuration, and troubleshooting ensure consistent performance, making U-PAD2 suitable for a broad range of analytical applications in research and industry.

Reference
DataApex Ltd. U-PAD2 A/D Converter Manual, Rev. M106/80E, Feb 2024.