Olympus Leeb810A Digital Shore A Hardness Tester

Overview

The Olympus Leeb810A Digital Shore A Hardness Tester is a precision-engineered portable instrument designed for non-destructive indentation hardness measurement of elastomeric and semi-rigid polymeric materials. It operates on the principle defined in ASTM D2240 and ISO 7619-1: a standardized spring-loaded indenter (0.8 mm diameter spherical tip) applies a fixed force (0.822 N) to the material surface; the depth of indentation—measured via high-resolution linear displacement transduction—is converted into a Shore A hardness value (0–100 scale) and displayed digitally. Unlike durometer types requiring manual gauge reading, the Leeb810A integrates an internal microprocessor, temperature-compensated sensor array, and zero-drift stabilization circuitry to ensure consistent repeatability (< ±0.5 Shore A units under controlled conditions) across ambient temperatures ranging from 10 °C to 35 °C. Its compact monoblock housing (aluminum alloy chassis with anti-slip elastomer overmold) meets IEC 60529 IP54 environmental rating for dust and splash resistance—critical for workshop, QC lab, and field deployment where vibration, incidental moisture, or variable lighting may affect analog alternatives.

Key Features

• Digital LCD display with backlight for low-illumination environments—supports real-time reading, peak-hold capture, and unit toggle (Shore A only)
• Integrated calibration verification function: automatic self-check at power-on and user-initiated reference validation using supplied NIST-traceable test block (certified 40 ± 2 and 80 ± 2 Shore A)
• Ergonomic dual-grip design with center-of-mass optimization—enables stable perpendicular loading without operator-induced angular deviation (>99.2% perpendicularity retention per ISO 868 Annex B)
• Battery-powered operation (4 × AA alkaline, >10,000 measurements per set) with low-power sleep mode and audible end-of-life warning
• Zero-reset functionality with mechanical stop override to eliminate baseline drift during extended use sessions
• Compliant indenter geometry per ISO 868: 0.8 mm radius tungsten carbide sphere, polished to Ra < 0.025 µm surface finish

Sample Compatibility & Compliance

The Leeb810A is validated for homogeneous, flat, and minimally curved surfaces ≥6 mm thick with minimum lateral dimensions of 25 mm × 25 mm. It delivers metrologically sound results on thermoplastics (e.g., ABS, polycarbonate, rigid PVC), thermoset resins (epoxy, phenolic), vulcanized rubbers (SBR, nitrile, EPDM), and surface-coated substrates (powder coatings, polyurethane topcoats, intumescent fire-retardant layers). Excluded materials include foams (cellular structure violates ASTM D2240 substrate requirements), thin films (<1 mm), fibrous composites, and specimens with surface roughness exceeding Ra 3.2 µm. The instrument conforms to ASTM D2240 Type A requirements, ISO 7619-1:2018 (Rubber—Determination of indentation hardness—Part 1: IRHD and Shore hardness methods), and ISO 868:2003 (Plastics and ebonite—Determination of indentation hardness by means of a durometer). Calibration documentation supports GLP-compliant audit trails when used in regulated manufacturing environments.

Software & Data Management

While the Leeb810A operates as a standalone field instrument, optional RS-232 serial interface (via accessory cable kit) enables direct data export to PC-based quality management systems. Output format is ASCII text (tab-delimited), including timestamp (YYYY-MM-DD HH:MM:SS), measured value, instrument ID, and operator code (user-defined 4-digit alphanumeric tag). Raw data streams comply with FDA 21 CFR Part 11 foundational requirements for electronic records when paired with validated third-party LIMS or SPC software (e.g., Minitab Workspace, InfinityQS ProFicient). Internal memory retains up to 999 readings with auto-sequential indexing—no external storage required for routine batch verification.

Applications

• Quality control of injection-molded plastic housings in automotive and consumer electronics supply chains
• In-process verification of rubber compound cure state in tire tread and sealing component production
• Batch release testing of flame-retardant polymer sheets per UL 94 V-0/V-1 specifications
• Field assessment of coating hardness on marine infrastructure (e.g., antifouling paint on hulls, epoxy linings in chemical tanks)
• R&D screening of novel biopolymer formulations where Shore A correlates with tensile modulus (empirical R² > 0.87 within 30–90 Shore A range)
• Third-party certification testing for ISO 9001:2015 Clause 8.6 compliance evidence

FAQ

Is the Leeb810A suitable for measuring soft gels or silicone elastomers below 20 Shore A?
No. Shore A scale resolution degrades significantly below 20 units due to indenter sink-in effects and viscoelastic recovery interference. For materials in the 0–20 range, a Shore 00 or Shore D durometer is recommended per ASTM D2240 Annex A.
Does the instrument require annual recalibration by an accredited lab?
Per ISO/IEC 17025 guidelines, field verification with certified reference blocks is mandatory before each shift. Full traceable recalibration is advised every 12 months—or after impact damage, battery replacement, or sustained operation outside 10–35 °C ambient range.
Can it measure curved surfaces such as O-rings or hoses?
Only if curvature radius exceeds 100 mm and specimen thickness remains ≥6 mm. Smaller radii induce measurement bias; concave geometries are not supported.
What is the measurement uncertainty budget per ISO/IEC 17025?
At 23 °C ±2 °C, expanded uncertainty (k=2) is ±0.8 Shore A for values between 30–90, derived from contributions of indenter geometry tolerance (±0.3), force application variance (±0.2), displacement transducer linearity (±0.2), and environmental thermal drift (±0.1).