Longteng ESJ205-S Dual-Range Analytical Balance with Internal Calibration
| Brand | Longteng |
|---|---|
| Origin | Liaoning, China |
| Model | ESJ205-S |
| Type | Analytical Balance |
| Maximum Capacity | 200 g |
| Dual Readability | 0.01 mg / 0.1 mg |
| Repeatability | ±0.03 mg |
| Internal Calibration | Fully Automatic |
| Pan Diameter | Φ90 mm |
| Display | Backlit LCD |
| Interface | RS232 |
| Compliance | ISO/IEC 17025-compatible operation environment |
| Dimensions (W×D×H) | 460 × 205 × 280 mm |
| Weight | 9.1 kg |
Overview
The Longteng ESJ205-S is a dual-range analytical balance engineered for precision mass measurement in regulated laboratory environments. It operates on the principle of electromagnetic force compensation (EMFC), where sample weight is counterbalanced by a precisely controlled electromagnetic current—ensuring high linearity, minimal hysteresis, and long-term stability. Designed to meet the metrological requirements of quality control (QC), research & development (R&D), and pharmaceutical formulation workflows, the ESJ205-S delivers 0.01 mg readability at its high-sensitivity range (up to 50 g) and switches automatically to 0.1 mg resolution for extended weighing up to 200 g. Its rear-mounted EMFC sensor architecture minimizes mechanical stress and thermal drift, while the triple-door draft shield provides optimal airflow management without compromising access or ergonomics.
Key Features
- Rear-mounted high-stability electromagnetic force compensation sensor with optimized thermal mass distribution for reduced sensitivity to ambient temperature fluctuations.
- Triple-door acrylic draft shield with wide-open interior volume (Φ90 mm stainless steel pan) accommodating tall or bulky containers—ideal for volumetric flask weighing and density determination setups.
- Full internal calibration system with built-in stainless steel reference weights; supports automatic calibration triggered by time intervals, temperature thresholds (±1 °C change), or manual initiation via front-panel controls.
- Backlit monochrome LCD display with adjustable brightness—enabling clear readability under both low-light biosafety cabinets and bright daylight conditions.
- Dual-range auto-switching functionality: seamless transition between 0.01 mg (0–50 g) and 0.1 mg (50–200 g) modes without user intervention or recalibration.
- Comprehensive error mitigation suite: overload/underload detection, full-span tare, temperature-compensated zero tracking, and linear drift correction algorithms compliant with ISO 9001 and GLP documentation practices.
Sample Compatibility & Compliance
The ESJ205-S accommodates a broad spectrum of sample types—from powders and granules to volatile solvents and hygroscopic compounds—thanks to its rapid stabilization time (<3 s for 95% response) and robust anti-static design. The stainless steel pan and sealed sensor chamber resist corrosion from common laboratory reagents. While not certified to OIML R76 or NIST Handbook 44 out-of-the-box, the balance supports traceable calibration using external Class E2 or F1 weights and is routinely deployed in ISO/IEC 17025-accredited labs for method validation per USP , EP 2.1.6, and ASTM E898. Its RS232 interface enables direct integration into LIMS or ELN systems with configurable ASCII output protocols.
Software & Data Management
Data export follows standard asynchronous serial communication (9600 baud, 8N1), compatible with Windows-based data acquisition software, Excel macros, and validated lab informatics platforms. Optional firmware upgrades support audit trail logging (user ID, timestamp, action type, pre-/post-value) aligned with FDA 21 CFR Part 11 requirements when paired with compliant host software. All calibration events—including auto-triggered and manual sessions—are timestamped and stored in non-volatile memory for retrospective review during internal audits or regulatory inspections.
Applications
- Pharmaceutical dosage form development: active pharmaceutical ingredient (API) dispensing, excipient blending verification, and tablet weight uniformity testing per USP .
- Chemical synthesis: stoichiometric reagent weighing, catalyst loading, and reaction yield quantification.
- Materials science: powder density profiling (with optional density kit), ash content determination, and gravimetric sorption analysis.
- Environmental testing labs: filter weighing for PM2.5/PM10 particulate matter analysis per EPA Method 201A.
- Academic research: micro-scale reaction monitoring, isotope ratio sample preparation, and nanomaterial mass characterization.
FAQ
What does “dual-range” mean for the ESJ205-S?
It refers to two distinct readability modes: 0.01 mg (for masses ≤50 g) and 0.1 mg (for masses up to 200 g), automatically selected based on load magnitude.
Is external calibration required after internal calibration?
Internal calibration ensures daily operational accuracy, but periodic verification with traceable external standards (e.g., annually or per SOP) remains mandatory for ISO/IEC 17025 compliance.
Can the balance be integrated into a GMP-controlled environment?
Yes—when used with validated software, secure user access controls, and documented calibration/maintenance logs, it meets foundational GMP data integrity expectations.
Does the RS232 interface support real-time streaming to LabVIEW or Python scripts?
Yes, using standard ASCII command sets (e.g., “S” for stable weight readout); no proprietary drivers are needed.
What environmental conditions optimize performance?
Operate within 15–30 °C, <70% RH, on a vibration-isolated bench away from air currents, HVAC vents, and electromagnetic sources (e.g., centrifuges, RF transmitters).
