OHAUS PX225DZH Precision Analytical Balance
| Brand | OHAUS |
|---|---|
| Origin | USA |
| Model | PX225DZH |
| Instrument Type | Analytical Balance |
| Maximum Capacity | 220 g |
| Readability | 0.01 mg (10 µg) |
| Minimum Weight (USP <0.1%) | 20 mg |
| Internal Calibration | Yes |
| Pan Size | 80 mm diameter stainless steel |
| Draft Shield | Integrated glass draft shield with sliding doors |
| Stabilization Time | ≤10 s |
| Operating Environment | 10–30 °C, ≤80% RH non-condensing |
| Power Supply | AC adapter (included) |
| Dimensions (H×L×W) | 309 × 321 × 209 mm |
| Net Weight | 4.5 kg |
| Connectivity | RS232 and USB (standard) |
| Display | Backlit dual-line LCD with contextual prompts |
| Compliance | GLP/GMP-ready with real-time clock, audit trail support, and user authentication |
Overview
The OHAUS PX225DZH is a high-precision analytical balance engineered for laboratories requiring reproducible mass measurements at the sub-milligram level. Designed in accordance with ISO/IEC 17025 and aligned with USP Chapter <41> and <1251> requirements for analytical weighing, it employs electromagnetic force compensation (EMFC) technology to deliver stable, drift-compensated readings under variable environmental conditions. Its 0.01 mg readability and verified minimum weight of 20 mg (per USP <41> at 0.1% uncertainty threshold) make it suitable for quantitative analysis in pharmaceutical quality control, reference standard preparation, and trace-level formulation work. The integrated glass draft shield—designed with low-turbulence airflow geometry—minimizes convective interference while enabling rapid stabilization (<10 s), critical for high-throughput QC workflows.
Key Features
- Electromagnetic force compensation sensor with temperature and linearity compensation algorithms
- Internal calibration system with automatic recalibration triggered by time, temperature drift, or user command
- Dual-line backlit LCD display with contextual second-line prompts for intuitive operation across four languages (English, Spanish, French, Chinese)
- Stainless steel 80 mm diameter weighing pan, removable for cleaning and traceability maintenance
- Full-coverage glass draft shield with front-sliding doors and integrated anti-static coating
- GLP/GMP-compliant real-time clock with timestamped data output and configurable print/export formats
- User-accessible parameter configuration: auto-zero tracking, auto-tare, display brightness, environmental damping settings, and stability threshold adjustment
- Software lock capability with password-protected menu access and full reset option for SOP compliance
- RS232 and USB interfaces supporting direct connection to LIMS, ELN, or statistical process control (SPC) software
Sample Compatibility & Compliance
The PX225DZH accommodates a wide range of sample forms—including powders, crystalline solids, small-volume liquids in tared vessels, and micro-vials—within its 220 g maximum capacity. Its underhook assembly supports density determination and magnetic susceptibility measurements via sinker mode. The balance meets ISO 9001 calibration traceability requirements when used with NIST-traceable weights and is compatible with FDA 21 CFR Part 11–compliant data management systems when paired with OHAUS Acquire software (v3.0+). All firmware operations retain immutable audit logs, including user ID, timestamp, calibration events, and weight data exports—supporting regulatory inspections under GMP, GLP, and ICH Q7 frameworks.
Software & Data Management
Data acquisition and reporting are streamlined through native RS232/USB protocols compatible with industry-standard platforms including LabWare LIMS, Thermo Fisher SampleManager, and custom Python-based SPC dashboards. The balance outputs ASCII-formatted strings with configurable delimiters and metadata headers (e.g., date/time, operator ID, unit, stability flag). Optional OHAUS Acquire software enables automated data logging, statistical summary generation (mean, SD, RSD, min/max), and export to CSV, Excel, or PDF with embedded digital signatures. All exported files include embedded timestamps and user-authenticated metadata, satisfying ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate) for regulated environments.
Applications
- Pharmaceutical: Potency assay preparation, active pharmaceutical ingredient (API) quantification, excipient blending verification
- Academic Research: Gravimetric synthesis monitoring, catalyst loading precision, isotopic tracer mass verification
- Materials Science: Nanoparticle yield calculation, thin-film deposition mass gain measurement, polymer additive dosing
- Environmental Testing: Filter mass differential for PM2.5/PM10 analysis, sorbent tube loading validation per EPA Method 5 and ISO 12103-1
- Clinical Diagnostics: Reagent kit component weighing, calibrator standard preparation, internal quality control material verification
FAQ
What is the minimum weight requirement per USP <41> for this balance?
The verified minimum weight is 20 mg at the 0.1% uncertainty threshold, confirmed using calibrated test weights and documented per OHAUS Certificate of Conformance (CoC).
Does the PX225DZH support 21 CFR Part 11 compliance?
Yes—when operated with OHAUS Acquire software v3.2 or later and configured with electronic signatures, audit trails, and role-based access control.
Can the balance be used without the draft shield?
No—the draft shield is integral to type approval and metrological performance; removal invalidates calibration and violates ISO 17025 environmental control requirements.
Is external calibration required after internal calibration?
Internal calibration ensures short-term accuracy; however, periodic external verification using Class E2 or better weights is mandated by ISO/IEC 17025 and internal SOPs for accredited labs.
What power source options are available?
Only the included AC adapter is supported; battery operation is not implemented due to stability and noise constraints inherent to EMFC architecture.
