Longteng ES-20F2 Precision Mass Comparator
| Brand | Longteng |
|---|---|
| Origin | Liaoning, China |
| Manufacturer Type | Authorized Distributor |
| Product Category | Domestic |
| Model | ES-20F2 |
| Price Range | USD 1,400 – 4,200 |
| Instrument Type | Precision Mass Comparator |
| Maximum Capacity | 20 kg |
| Minimum Readability | 0.02 g |
| Repeatability | ±0.02 g |
| Calibration Method | Automatic Internal Calibration |
| Pan Size | 340 × 300 mm |
| External Dimensions | 460 × 315 × 160 mm |
| Compliance | Designed for OIML R111-1 Class F2 and ASTM E617-22 reference mass verification workflows |
Overview
The Longteng ES-20F2 Precision Mass Comparator is an electromechanical force-compensation balance engineered specifically for high-reproducibility comparative mass metrology in calibration laboratories, national metrology institutes (NMIs), and industrial quality control environments. Unlike general-purpose analytical or precision balances, the ES-20F2 operates under a dedicated comparator mode—optimized for differential weighing between reference standards and test masses—leveraging a high-stability electromagnetic force restoration sensor architecture. Its design adheres to core metrological principles outlined in OIML R111-1 for weight class assignment and supports traceable comparisons within F2 tolerance limits (±32 mg at 20 kg). The instrument is not intended for direct mass assignment but serves as a primary tool for relative mass difference determination with minimal drift and thermal hysteresis, enabling compliance with ISO/IEC 17025:2017 clause 6.4.2 on measurement equipment suitability.
Key Features
- Force-compensated electromagnetic transducer system with dual-range auto-ranging capability: optimized for both 20 kg full-scale comparison and sub-gram differential resolution
- Automatic internal calibration routine activated via front-panel menu or remote command, utilizing built-in reference weights traceable to NIM (China National Institute of Metrology)
- Stabilized weighing chamber with draft shield integration and low-thermal-mass pan assembly (340 × 300 mm stainless steel)
- Digital filtering algorithm with adjustable response time (0.5–3 s) to suppress mechanical vibration and air-current-induced noise
- Real-time stability indicator and automatic zero-tracking function to maintain baseline integrity during extended comparison sequences
- Rugged aluminum alloy chassis with anti-vibration damping feet, rated for operation on Class M2 laboratory tables per ISO 5725-2
Sample Compatibility & Compliance
The ES-20F2 accommodates standard cylindrical, rectangular, and hexagonal cast-iron or stainless-steel reference masses conforming to OIML R111-1 geometries (Classes E1–F2). It supports comparative weighing protocols for 1 kg to 20 kg test pieces, including sets used in torque calibrations, pressure gauge deadweight testers, and material density reference blocks. The instrument meets mechanical and environmental requirements specified in JJG 99-2023 (Chinese Verification Regulation for Weights) and aligns with functional performance benchmarks in ASTM E617-22 Annex A3 for mass comparator validation. While not certified to ISO/IEC 17025 itself, its metrological characteristics—including repeatability (±0.02 g), linearity deviation (<0.03 g), and temperature coefficient (≤2 ppm/°C)—are documented in factory acceptance test reports supplied with each unit.
Software & Data Management
The ES-20F2 interfaces via RS-232 and optional USB-to-serial adapter for bidirectional communication with metrology software platforms such as MET/CAL, GUM Workbench, or custom LabVIEW-based comparison scripts. All weighing events—including tare, net, differential, and sequence modes—are timestamped and logged with operator ID, ambient temperature/humidity metadata (when connected to external sensors), and digital signature fields. Audit trail functionality satisfies basic GLP/GMP data integrity expectations; however, full 21 CFR Part 11 compliance requires integration with validated third-party LIMS or electronic lab notebook (ELN) systems. Export formats include CSV, TXT, and XML, supporting automated import into uncertainty budgeting tools per GUM Supplement 1.
Applications
- Periodic verification of F2-class working standards against E2 or F1 references in regional calibration labs
- Inter-laboratory comparison exercises coordinated by CNAS or APMP for mass metrology proficiency testing
- Production-line verification of cast-iron test weights prior to OIML certification
- Differential weighing in density determination setups using Archimedean buoyancy correction protocols
- Supporting uncertainty analysis for torque transducer calibration where mass-derived force values require tight bounds
FAQ
What mass classes can the ES-20F2 verify?
It is suitable for comparative verification of weights up to Class F2 (20 kg), with optimal performance observed for masses between 1 kg and 20 kg.
Does the ES-20F2 support external temperature compensation?
No—the unit relies on internal thermal stabilization and does not accept external Pt100 or thermistor inputs; ambient temperature should be maintained within 18–23 °C per JJG 99-2023.
Can it perform multi-step sequential comparisons without manual intervention?
Yes—via ASCII command protocol, users may program up to 12-step comparison cycles (e.g., REF–TEST–REF) with programmable dwell times and statistical output.
Is the pan removable for cleaning or replacement?
Yes—the 340 × 300 mm stainless-steel pan is secured with four M4 screws and may be removed without recalibration if reinstalled identically.
What documentation is provided for metrological traceability?
Each unit ships with a Factory Calibration Report (traceable to NIM), OIML R111-1 conformance statement, and ISO 9001-certified manufacturing process documentation.
