Chengyi CZD-1 Automatic Potentiometric Titrator
| Brand | Chengyi (scchengyi) |
|---|---|
| Origin | Sichuan, China |
| Model | CZD-1 |
| Measurement Range | pH 0.00–14.00 |
| Accuracy | ±0.06 pH (pH measurement), ±0.2% (volumetric repeatability) |
| Resolution | 0.01 pH / 1 mV |
| Stability | ±0.01 pH per 3 h |
| Endpoint Setting Range | 0.00–14.00 pH or ±1400 mV |
| Control Sensitivity | ±0.1 pH / ±5 mV |
| Power Supply | AC 220 V ±10%, 50 Hz |
| Power Consumption | 10 W |
| Net Weight | 5 kg |
| Environmental Operating Conditions | 5–40 °C, ≤85% RH |
Overview
The Chengyi CZD-1 Automatic Potentiometric Titrator is a benchtop electrochemical analyzer engineered for precision endpoint detection in potentiometric titrations. It operates on the fundamental principle of monitoring potential difference (in mV) or hydrogen ion activity (as pH) between a reference electrode and an indicator electrode during incremental reagent addition. The instrument integrates real-time temperature compensation via a calibrated PT100 platinum resistance sensor, correcting Nernstian response drift across the full 0–100 °C operational range—critical for maintaining stoichiometric accuracy in thermally sensitive reactions such as weak acid–strong base titrations or redox systems with temperature-dependent formal potentials. Designed to meet ISO 8655-6 (volumetric apparatus — titrators) and ASTM E2087 (standard practice for potentiometric titration), the CZD-1 delivers traceable, reproducible results suitable for method validation under GLP-compliant laboratory environments.
Key Features
- Integrated PT100 temperature sensor with automatic thermal compensation algorithm applied to both pH and mV measurements
- Dual-mode endpoint detection: fixed-point (preset pH/mV threshold) and dynamic slope-based (first-derivative dE/dV) algorithms
- High-stability analog front-end with ±0.03 pH electronic unit accuracy and <0.01 pH/3 h baseline drift
- 0.01 pH resolution and 1 mV digital resolution, compliant with IUPAC recommendations for quantitative titrimetry
- Robust mechanical architecture supporting burette volumes up to 50 mL with glass or polymeric delivery systems
- Front-panel keypad interface with LCD display; no external PC required for basic operation
- Compliance with IEC 61010-1 safety standards for laboratory electrical equipment
Sample Compatibility & Compliance
The CZD-1 supports aqueous and mixed-solvent systems compatible with standard pH glass electrodes, silver/silver chloride reference electrodes, and redox-sensitive indicators (e.g., platinum microelectrodes). It accommodates common titration modes including acid–base, redox (e.g., Ce⁴⁺/Fe²⁺, KMnO₄/oxalate), precipitation (AgNO₃/Cl⁻), and complexometric (EDTA/Mg²⁺) protocols. All measurement electronics conform to electromagnetic compatibility (EMC) requirements per EN 61326-1. Data integrity is maintained through non-volatile memory storage of calibration records, endpoint logs, and user-defined method parameters—enabling audit readiness for ISO/IEC 17025-accredited testing laboratories.
Software & Data Management
While the CZD-1 operates autonomously via its embedded firmware, optional RS-232 or USB-to-serial interface enables connection to LIMS or custom data acquisition platforms. Raw titration curves (E vs. V), derivative plots (dE/dV vs. V), and final endpoint reports are exportable in CSV format. Calibration history—including date, operator ID, buffer lot numbers, and slope/offset values—is retained with timestamping. Though not natively 21 CFR Part 11 compliant, the system supports manual documentation workflows aligned with FDA-regulated QC/QA procedures when paired with controlled access logbooks and versioned SOPs.
Applications
- Quantitative determination of total acidity in food extracts (e.g., vinegar, fruit juices) per AOAC 973.05
- Chloride content analysis in drinking water and wastewater samples (ASTM D3279)
- Calcium and magnesium hardness titration in environmental water matrices using EDTA
- Redox titration of iron(II) in pharmaceutical intermediates (USP <791>)
- Acid number and base number measurement in lubricating oils (ASTM D974, D2896)
- Teaching laboratories: hands-on instruction in electrochemical principles, Nernst equation validation, and titration curve interpretation
FAQ
Does the CZD-1 support GLP-compliant data recording?
Yes—when used with documented calibration procedures and manually maintained logbooks, it meets core GLP data traceability requirements for non-automated instruments.
Can it perform back-titrations?
Yes, via manual volume entry and endpoint reversal logic; the instrument calculates net titrant consumption based on initial and residual volumes.
Is electrode calibration automated?
No—calibration is performed manually using two-point (e.g., pH 4.01/7.00 or 7.00/10.01) or single-point methods; slope and offset values are entered directly into the interface.
What maintenance is required for long-term stability?
Regular cleaning of electrode junctions, periodic verification against certified buffer standards, and annual verification of burette piston seal integrity are recommended.
Is the PT100 sensor replaceable by the user?
Yes—the sensor is field-serviceable with standard M12 connector interface; replacement requires recalibration of the temperature channel using ice-water and boiling-water reference points.
