Hershey ES5000-2 Intelligent Balance System for Blood Component Processing
| Brand | Hershey |
|---|---|
| Model | ES5000-2 |
| Max Capacity | 5000 g |
| Readability | 1 g |
| Repeatability | 1 g |
| Linearity | ±1 g |
| Stabilization Time | 1.5 s |
| Operating Temperature | 10–35 °C |
| Power Supply | AC 220 V, 50 Hz |
| Pan Dimensions (per pan) | 175 × 175 mm |
| Environmental Compliance | Designed for ISO 13485-aligned blood bank environments |
| Calibration | Manual |
| Built-in Counterweight Set | 49 g total (2×3 g, 2×4 g, 1×5 g, 1×10 g, 1×20 g), silicone-rubber encapsulated, non-toxic, certified to ≤0.1 g per piece accuracy |
Overview
The Hershey ES5000-2 Intelligent Balance System is a dual-pan, microprocessor-controlled weighing and balancing instrument engineered specifically for blood component processing workflows in transfusion medicine and blood banking facilities. Unlike general-purpose laboratory balances, the ES5000-2 implements a dedicated mass-matching algorithm that calculates real-time differential weight between two blood bags—enabling rapid, operator-guided counterbalancing prior to centrifugation. Its measurement principle relies on high-stability electromagnetic force compensation transducers calibrated to meet the static load and repeatability requirements of low-speed refrigerated centrifuges (e.g., 3,000–4,500 rpm, RCF ≤ 5,000 × g). The system operates within a defined environmental envelope (10–35 °C, non-condensing humidity) and is validated for use in environments compliant with CLSI GP44-A4, AABB Standards for Blood Banks, and ISO 13485:2016 quality management systems for medical devices.
Key Features
- Dual independent weighing pans (175 × 175 mm each), optimized for standard blood bag dimensions and compatible with cryo-bags up to 600 mL volume
- Integrated counterweight kit (49 g total), housed in medical-grade silicone rubber; individual weights certified to ±0.1 g tolerance and traceable to national metrological standards
- Microcontroller-based interface with LED display showing simultaneous left/right mass, delta value, and balance status (±g or “BALANCED” indicator)
- Stabilization time of ≤1.5 seconds under nominal loading conditions (2000–5000 g range), minimizing workflow interruption during high-throughput blood processing
- Manual calibration protocol compliant with internal quality control procedures; supports periodic verification using Class M2 reference weights
- Robust mechanical architecture with reinforced ABS housing and anti-slip rubber feet, rated for continuous operation in clinical laboratory settings
Sample Compatibility & Compliance
The ES5000-2 accepts all standard blood collection bags (PVC, CPDA-1, EDTA, citrate-phosphate-dextrose formulations) and platelet-rich plasma (PRP) containers used in automated or semi-automated separation protocols. It does not require direct integration with centrifuge controllers but interfaces seamlessly with documented SOPs for pre-centrifugation weight matching. The device meets essential safety and performance criteria outlined in IEC 61010-1 (electrical safety), EN 45501 (non-automatic weighing instruments), and is designed to support GLP-compliant recordkeeping when paired with external audit-trail-enabled data loggers. While not FDA 510(k)-cleared as a standalone medical device, it functions as an ancillary process control tool within FDA-regulated blood establishments operating under 21 CFR Part 606.
Software & Data Management
The ES5000-2 operates without embedded software or network connectivity; all functionality is implemented via firmware-resident logic. Weight data is displayed locally only and is not stored internally. For traceability, users are advised to document balance readings manually or integrate the unit into a validated electronic quality management system (eQMS) via external RS-232 or USB-to-serial adapters (optional accessory). When connected, the device outputs ASCII-formatted weight strings (e.g., “L:2450 R:2449 Δ:+1”) compatible with LIMS platforms supporting ASTM E1382-compliant data ingestion. Audit trail generation, user authentication, and electronic signature functionality must be managed externally per 21 CFR Part 11 requirements.
Applications
- Pre-centrifugation balancing of whole blood units prior to fractionation in large-capacity refrigerated centrifuges (e.g., Sorvall RC6+, Thermo Scientific Legend RT)
- Verification of equal mass distribution across paired buckets in swing-out rotors to prevent mechanical stress and rotor imbalance alarms
- Quantitative verification of red blood cell (RBC) suspension volumes post-wash or additive solution exchange
- Supporting compliance with AABB Standard 5.11.1 (Centrifuge Safety) and CAP checklist TRM.42320 (Balancing Verification)
- Quality control checkpoint in platelet pooling, cryoprecipitate preparation, and leukoreduction workflows
FAQ
Is the ES5000-2 suitable for sterile field use?
No—it is intended for use in controlled but non-sterile pre-processing areas (e.g., blood bank prep rooms). The unit is not autoclavable or IP-rated for wet decontamination.
Can it be calibrated with third-party weights?
Yes, provided the weights conform to OIML R111 Class M2 specifications and are accompanied by valid calibration certificates traceable to NIST or equivalent national metrology institutes.
Does it support automatic data export to hospital information systems?
Not natively. Data export requires optional serial interface hardware and middleware configuration aligned with local IT security policies and HL7/FHIR interoperability frameworks.
What maintenance is required beyond routine cleaning?
Annual verification by an accredited metrology service provider is recommended; no scheduled internal recalibration is necessary under normal operating conditions.
Is the silicone counterweight set latex-free?
Yes—all elastomeric components are certified latex-free and comply with ISO 10993-5 cytotoxicity testing requirements.
