Yoke JA-5003N Precision Analytical Balance
| Brand | Yoke |
|---|---|
| Origin | Shanghai, China |
| Manufacturer Type | Direct Manufacturer |
| Country of Origin | China |
| Model | JA-5003N |
| Instrument Type | Precision Balance |
| Maximum Capacity | 500 g |
| Readability | 1 mg |
| Calibration Method | External |
| Pan Diameter | 80 mm |
| Working Height Under Draft Shield | 240 mm |
| Dimensions (W×D×H) | 350 × 215 × 340 mm |
| Net Weight | 7.5 kg |
| Power Supply | 220 V / 50 Hz |
| Display | Backlit LCD (120 × 55 mm) |
| Interface | RS232 standard port |
| Unit Options | g, oz, ct |
| Environmental Protection | Four-sided electrostatically coated glass draft shield |
Overview
The Yoke JA-5003N Precision Analytical Balance is an entry-level laboratory balance engineered for reproducible mass measurement in quality control, academic teaching labs, and routine analytical workflows. It operates on electromagnetic force compensation principle—where the load cell generates a counteracting current proportional to the sample mass—to deliver stable, drift-compensated readings at 1 mg readability across its full 0–500 g range. Designed for ISO/IEC 17025-compliant environments, the JA-5003N meets fundamental metrological requirements for Class II precision balances per OIML R76 and ASTM E1222. Its compact footprint and rigid aluminum-alloy base support vibration damping, while the integrated four-sided electrostatically coated glass draft shield ensures consistent performance in non-climate-controlled lab spaces with ambient electrostatic activity.
Key Features
- High-contrast backlit LCD display (120 × 55 mm) with intuitive icon-based navigation and real-time status indicators for stabilization, calibration, and unit selection
- German STL Institute-derived sensor firmware architecture enabling multi-point linearization—improving repeatability across the entire weighing range without requiring internal recalibration
- Electrostatically coated tempered glass draft shield with full perimeter sealing; reduces electrostatic interference by >90% compared to standard acrylic enclosures (tested per IEC 61340-5-1)
- RS232 serial interface compliant with TIA/EIA-232-F standards, supporting direct connection to thermal printers, LIMS terminals, or PC-based data logging software without adapter drivers
- Three programmable weighing units—grams (g), ounces (oz), and carats (ct)—with automatic zero-tracking and auto-tare functions activated within ±2 s of pan stabilization
- External calibration capability using certified Class M2 weights (not included); calibration sequence adheres to EURAMET cg-18 guidelines for verification of linearity and eccentricity error
Sample Compatibility & Compliance
The JA-5003N accommodates standard laboratory vessels—including weighing boats, crucibles, and volumetric flasks—within its 80 mm diameter stainless-steel weighing pan. The 240 mm vertical clearance beneath the draft shield permits use of tall containers up to 220 mm in height. The balance complies with CE marking directives (2014/30/EU EMC and 2014/35/EU LVD), RoHS 2011/65/EU, and supports GLP/GMP documentation workflows through timestamped RS232 output (date/time stamp enabled via host software). While not FDA 21 CFR Part 11–validated out-of-the-box, audit trails can be generated when paired with compliant third-party data acquisition systems meeting ALCOA+ principles.
Software & Data Management
No proprietary software is bundled; however, the RS232 interface transmits ASCII-formatted weight data (e.g., “S: +000.1234 g”) at user-selectable baud rates (9600–115200 bps). Compatible with generic terminal emulators (e.g., PuTTY, Tera Term), Microsoft Excel via Power Query, and validated LIMS platforms including LabVantage and STARLIMS. Data export includes optional prefix/suffix identifiers and automatic carriage-return line-feed termination. Firmware versioning (v2.4.x) supports field-upgradable calibration coefficients via serial command protocol documented in the technical manual.
Applications
- Pharmaceutical raw material dispensing in non-sterile QC labs (USP tolerance verification for 500 mg–5 g batches)
- Chemistry teaching labs: stoichiometric reagent preparation, gravimetric analysis, and molar mass determination
- Food testing laboratories performing moisture content assays per AOAC 950.46 using pre- and post-drying mass differentials
- Environmental labs quantifying filter weights in suspended solids (TSS) analysis (EPA Method 160.1)
- Materials science labs measuring coating thickness via mass gain on substrates (ASTM D4082)
FAQ
What calibration weights are required for external calibration?
A certified Class M2 weight of 500 g (or 200 g for partial-range verification) traceable to NIM or BIPM standards is required. Calibration must be performed at ambient temperature (18–23 °C) with relative humidity below 70% RH.
Does the balance support internal calibration or motorized draft shield operation?
No—the JA-5003N relies exclusively on external calibration and features a manually operated sliding glass shield. Internal calibration and automated mechanisms are reserved for higher-tier models (e.g., JA-5003P series).
Can the RS232 output be configured for continuous streaming mode?
Yes—via command “S0” (stable-only) or “S1” (continuous transmission at 2 Hz), both configurable through terminal commands. Output format is fixed-width ASCII with no checksum.
Is the balance suitable for use in fume hoods?
Not recommended—draft shields are not rated for negative-pressure environments. Air turbulence and chemical vapors may compromise repeatability and accelerate sensor corrosion.
What is the warm-up time before first use?
Minimum 30 minutes after power-on under stable ambient conditions; extended warm-up (60 min) is advised prior to GLP-critical measurements.
