Yoke JA-N Series Precision Balance

Overview

The Yoke JA-N Series Precision Balance is an entry-level analytical-grade weighing instrument engineered for laboratories requiring reliable, high-reproducibility mass measurement at 1 mg readability. Built upon electromagnetic force compensation (EMFC) sensor architecture, the JA-N series delivers stable and drift-resistant performance across its full capacity range—from 200 g to 500 g—making it suitable for routine quality control, educational labs, pharmaceutical sample preparation, and materials testing where ISO/IEC 17025-compliant traceability is essential. Unlike strain-gauge-based platforms, EMFC technology ensures linearity and temperature insensitivity without mechanical wear, supporting long-term calibration stability. The balance operates under standard laboratory conditions (20 ± 5 °C, <70% RH non-condensing), with internal thermal compensation algorithms minimizing environmental influence on measurement integrity.

Key Features

• Electromagnetic force compensation (EMFC) transducer system with multi-point linearization software licensed from STL Institute (Germany), enabling enhanced accuracy across the entire weighing range.
• Large backlit LCD display (120 × 55 mm) with high-contrast alphanumeric rendering—optimized for low-glare visibility in ambient lab lighting and compatible with protective eyewear use.
• Four-sided draft shield constructed from electrostatically coated optical glass, providing effective shielding against static charge accumulation and air turbulence while maintaining unobstructed visual access to the weighing pan.
• External calibration capability via certified weights (Class M2 or better), compliant with ISO 9001 and ISO/IEC 17025 calibration documentation requirements.
• RS232 serial interface supporting bidirectional communication with PCs, label printers, and LIMS systems—enabling automated data logging without manual transcription errors.
• Integrated functions including full-range tare, piece counting (with user-defined unit weight), auto-zero tracking, and four-stage shock absorption to mitigate floor-borne vibration interference.

Sample Compatibility & Compliance

The JA-N series accommodates standard laboratory samples up to 500 g using an 80 mm diameter stainless-steel weighing pan. Its 240 mm vertical working clearance allows compatibility with volumetric flasks, beakers, and crucibles commonly used in gravimetric analysis. All models meet CE marking requirements per Directive 2014/30/EU (EMC) and 2014/35/EU (LVD). While not certified for hazardous area use (ATEX/IECEx), the balance conforms to EN 45501:2015 for non-automatic weighing instruments, ensuring metrological compliance with OIML R76-1 recommendations. For regulated environments—including GLP and GMP facilities—the device supports audit-ready operation when paired with external calibration records and user-accessible calibration logs.

Software & Data Management

Data output via RS232 follows standard ASCII protocol with configurable baud rates (9600–115200 bps), parity, and stop bits. Output formats include net weight, gross weight, tare value, and unit identifier (g, oz, ct), fully compatible with Excel, LabArchives, and industry-standard LIMS platforms. Optional PC software (sold separately) enables real-time graphing, statistical process control (SPC) charting, and PDF report generation with embedded timestamp, operator ID, and calibration status. The balance maintains a local history buffer of up to 99 entries, each timestamped and tagged with mode (weighing, counting, calibration), satisfying basic 21 CFR Part 11 record-keeping expectations when used in conjunction with procedural controls.

Applications

• Pharmaceutical formulation: Accurate dispensing of active pharmaceutical ingredients (APIs) and excipients during batch preparation (USP <41> compliant).
• Chemistry education: Stoichiometric calculations, molar mass determination, and solution preparation in undergraduate teaching labs.
• Quality assurance: Incoming raw material verification, finished product sampling, and packaging weight checks per ISO 2859-1 AQL protocols.
• Materials science: Density determination via displacement method, powder flow characterization (e.g., Hall flowmeter calibration), and catalyst loading quantification.
• Food testing labs: Nutrient labeling compliance (FDA 21 CFR 101.9), moisture content by loss-on-drying (AOAC 950.46), and portion control validation.

FAQ

What calibration standards are recommended for external calibration of the JA-N series?
Class M2 or better calibration weights traceable to national metrology institutes (e.g., NIST, PTB, or NIM) are required. Calibration should be performed at least daily before first use and after any relocation or environmental shift exceeding ±2 °C.
Is the JA-N series compatible with Windows 11 and macOS Ventura or later?
Yes—when connected via RS232-to-USB adapter (FTDI chipset recommended), the balance functions as a virtual COM port and is recognized natively by all major operating systems without proprietary drivers.
Does the balance support internal calibration or only external?
The JA-N series is externally calibrated only. No internal motorized calibration mass is integrated; this design prioritizes cost-effectiveness and mechanical simplicity for non-regulated or semi-regulated workflows.
Can the draft shield be removed for cleaning or large-sample weighing?
Yes—the four-panel glass shield is tool-free detachable and reassembles with precision alignment pins to ensure repeatable aerodynamic performance after reinstallation.
What is the warm-up time required to achieve specified repeatability?
A minimum 30-minute stabilization period is recommended after power-on under constant ambient conditions to allow thermal equilibrium of the EMFC sensor and internal electronics.