OHAUS pH Calibration Buffer Solutions Kit
| Brand | OHAUS |
|---|---|
| Origin | Jiangsu, China |
| Manufacturer Type | Manufacturer |
| Product Category | Domestic |
| Model | pH Calibration Buffer Solutions |
| Pricing | Upon Request |
Overview
OHAUS pH Calibration Buffer Solutions are high-purity, traceable reference standards engineered for accurate and repeatable calibration of pH meters and ion-selective electrodes in laboratory, quality control, and field applications. These aqueous buffer solutions conform to ISO 3696 (Grade 3 water) and NIST-traceable pH certification protocols, ensuring metrological reliability across the full operational pH range (1.68–12.45). Each solution is formulated using certified primary reference materials and rigorously tested for thermal stability, ionic strength consistency, and temperature-dependent pH drift—critical parameters defined in ASTM D1293 and ISO 10523 for electrochemical measurement integrity. The dual-port bottle design enables both gravity-fed dispensing and pressure-assisted delivery while integrating an integrated check valve to prevent backflow contamination—a feature essential for maintaining long-term solution integrity during repeated use in regulated environments.
Key Features
- Dual-port polypropylene bottles with integrated non-return valve to eliminate cross-contamination and preserve solution purity during pipetting or automated dosing
- Individually labeled, lot-numbered vials with NIST-traceable pH certification certificates (including uncertainty values at 25 °C)
- Optimized formulation for minimal CO₂ absorption—especially critical for high-pH buffers (pH 9.18, 10.01, 12.45) to reduce alkaline drift
- Stable shelf life of 12 months from manufacture date when unopened and stored at 15–25 °C in opaque, sealed conditions
- Available as single-bottle units (250 mL) or pre-configured 6-bottle calibration kits covering standard IUPAC-recommended points (1.68, 4.01, 6.86, 7.00, 9.18, 10.01, 12.45)
- Compatible with all OHAUS ST-series, AB-series, and ZH-series benchtop, portable, and multiparameter instruments—including pH, mV, ion concentration, and conductivity modes
Sample Compatibility & Compliance
These buffers are validated for use with OHAUS pH meters (e.g., ST300, ST400, ST5000 series), AB23/AB41/AB33 pH and EC meters, and ST-series multiparameter analyzers. All formulations meet ISO/IEC 17025 requirements for reference material traceability and are suitable for GLP- and GMP-regulated workflows where audit-ready documentation is required. The pH 4.01 and 7.00 solutions comply with USP for pharmaceutical pH verification; pH 1.68 and 12.45 support extreme-range electrode characterization per ASTM E70. Each lot undergoes independent third-party verification for pH accuracy (±0.01 pH unit at 25 °C) and temperature coefficient conformity (d(pH)/dT).
Software & Data Management
While the buffer solutions themselves are consumables, they integrate seamlessly into OHAUS instrument firmware calibration routines—including auto-recognition of buffer ID via QR-coded labels on select kit configurations. When used with ST400M or AB33M1 multiparameter platforms, calibration events are timestamped, logged with operator ID, and exportable in CSV format compliant with FDA 21 CFR Part 11 requirements (when paired with validated OHAUS LabX® Connect software). Audit trails include buffer lot number, expiration date, calibration slope/mV offset, and electrode response time—enabling full traceability for regulatory submissions.
Applications
- Two- or three-point calibration of glass electrode-based pH meters in environmental water testing (EPA Method 150.1)
- Verification of electrode asymmetry potential and zero-point drift in QC laboratories performing raw material release testing
- Calibration of ISFET and solid-state pH sensors used in bioprocess monitoring
- Validation of portable pH testers in food safety inspections (ISO 21843)
- Supporting ISO 5725-2 accuracy assessments for inter-laboratory comparison studies
- Preventive maintenance of pH electrodes through periodic reconditioning using low- and high-pH buffers
FAQ
What is the recommended storage condition for unopened OHAUS pH buffers?
Store upright in original packaging at 15–25 °C, protected from direct light and ambient CO₂ exposure. Do not refrigerate.
Why does pH 9.18 buffer have a shorter effective working life after opening?
Carbon dioxide absorption from air lowers measured pH over time; use within 1 week after opening and always cap immediately after dispensing.
Are these buffers compatible with non-OHAUS pH meters?
Yes—these are universal calibration standards meeting international pH reference specifications and function with any meter supporting standard two-point or multi-point calibration protocols.
How is traceability documented for each lot?
Each bottle includes a certificate of analysis listing certified pH value ± expanded uncertainty (k=2), reference temperature, ionic strength, and NIST traceability statement.
Can I use the same buffer for both calibration and electrode storage?
No—only pH 4.01 or pH 7.00 buffers are suitable for short-term storage (≤24 h); long-term storage requires dedicated electrode storage solution to prevent junction clogging or glass membrane dehydration.
