QL TG328A Analytical Balance with Mechanical-Optical Readout
| Brand | QL |
|---|---|
| Origin | Jiangsu, China |
| Model | TG328A |
| Type | Analytical Balance |
| Capacity | 0–200 g |
| Readability | 0.1 mg |
| Optical Scale Range | 0–10 mg |
| Mechanical Weights Range | 0.01–199.99 g |
| Pan Diameter | Ø75 mm |
| Dimensions (W×D×H) | 420 × 370 × 500 mm |
| Net Weight | 18 kg |
| Calibration | Manual |
| Compliance | Designed for GLP-compliant laboratory environments |
Overview
The QL TG328A Analytical Balance is a precision mechanical-optical weighing instrument engineered for high-reproducibility mass measurement in regulated laboratory settings. Unlike modern electromagnetic force-compensation balances, the TG328A employs a classic double-pan beam mechanism augmented by an optical lever system for fine-scale interpolation—offering inherent stability, minimal drift, and long-term calibration retention without reliance on electronic sensors or power-dependent components. Its design adheres to foundational metrological principles defined in ISO 9001 and ASTM E898 for analytical balance performance verification. With a maximum capacity of 200 g and readability of 0.1 mg (100 µg), it satisfies the minimum sensitivity requirements for quantitative gravimetric analysis, standard solution preparation, and sample aliquoting in quality control labs, academic research, and metallurgical testing facilities.
Key Features
- Robust dual-beam mechanical architecture with hardened steel knife-edge fulcrum and precision-ground brass weights for consistent torque transmission and low hysteresis.
- Integrated optical scale system providing 0–10 mg interpolation via calibrated vernier projection—enabling direct visual readout without digital conversion artifacts.
- Full mechanical weight set (0.01–199.99 g) housed in a shielded drawer with anti-static lining to prevent dust accumulation and weight corrosion.
- Stainless-steel weighing pan (Ø75 mm) mounted on adjustable leveling feet with bubble level indicator for rapid mechanical alignment.
- Enclosed draft shield-compatible housing (420 × 370 × 500 mm) constructed from rigid phenolic resin laminate to minimize thermal expansion effects and acoustic vibration coupling.
- Manual external calibration using certified Class M2 reference weights—fully traceable to national metrology institutes per ISO/IEC 17025 guidelines.
Sample Compatibility & Compliance
The TG328A accommodates solid, powdered, and granular samples up to 200 g, including reference standards, metal alloys (e.g., pure iron, tin granules), crucibles, quartz tubes, and ceramic electrodes. Its mechanical design eliminates electromagnetic interference risks—making it suitable for use near furnaces, induction heaters, or RF-emitting instrumentation. The balance meets baseline functional requirements for ISO 17025-accredited laboratories performing gravimetric assays under GLP or GMP frameworks. While not electronically audit-trail enabled, its manual calibration logs, operator sign-off records, and physical weight traceability support full compliance with FDA 21 CFR Part 11 documentation expectations when integrated into validated SOPs.
Software & Data Management
As a purely mechanical-optical instrument, the TG328A does not incorporate embedded firmware, USB interfaces, or data logging capabilities. All measurements are recorded manually by the operator onto standardized lab notebooks or LIMS-integrated paper forms. This analog architecture ensures immunity to cybersecurity vulnerabilities, software obsolescence, and firmware update dependencies—critical for legacy-system-integrated environments or laboratories maintaining strict validation continuity. Documentation workflows align with Annex 11 (EU GMP) principles requiring “human-readable, permanent, and attributable” records. Optional accessories—including calibrated weight sets, draft shields, and anti-vibration tables—are supplied with NIST-traceable certificates of calibration.
Applications
- Gravimetric determination of moisture content, ash residue, and volatile loss in metallurgical and mineralogical samples (ASTM E1867, ISO 562).
- Preparation of primary standard solutions for titrimetry and ICP-OES calibration (USP , EP 2.1.6).
- Weighing of crucibles, electrodes, and quartzware prior to high-temperature combustion or fusion procedures.
- Educational demonstration of classical mass metrology principles in university physics and analytical chemistry curricula.
- Verification and intermediate checks of electronic analytical balances using independent mechanical reference.
FAQ
Is the TG328A compliant with ISO/IEC 17025 for accredited testing laboratories?
Yes—when operated within documented procedures, calibrated using traceable weights, and maintained per manufacturer specifications, it satisfies clause 6.4.6 (Equipment Verification) and 6.5.2 (Reference Standards) of ISO/IEC 17025:2017.
Can it be used in environments with electromagnetic interference?
Yes—the absence of electronic components renders it inherently immune to EMI, making it suitable for proximity to induction furnaces, XRF spectrometers, or high-current power supplies.
What is the recommended recalibration frequency?
Per ISO 17025 and internal QA protocols, recalibration is required before each analytical session when used for critical measurements; at minimum, daily verification with check weights is advised.
Does it support automated data export?
No—data capture is manual. For digital integration, users may employ external barcode-scanned logbooks or third-party optical character recognition (OCR) systems trained on its optical scale output.
Are replacement mechanical weights available with calibration certificates?
Yes—QL provides M2-class stainless-steel weight sets (0.01 g to 100 g) accompanied by UKAS- or CNAS-accredited calibration reports valid for 12 months.
