Koehler K95300 Low-Temperature Grease Flow Tester

Overview

The Koehler K95300 Low-Temperature Grease Flow Tester is a precision-engineered instrument designed to quantify the flow resistance of lubricating greases under controlled sub-ambient conditions, in strict accordance with DIN 51805. This standardized method evaluates the pressure required to initiate flow of a grease sample at defined low temperatures—typically ranging from ambient down to –50 °C—by measuring the critical air pressure at which the grease begins to deform and extrude through a calibrated capillary tip. The instrument employs a sealed, thermally insulated metal block housing a temperature-controlled cavity, ensuring stable thermal equilibrium during measurement. Unlike conventional systems requiring external cryogenic cooling, the K95300 integrates a self-contained refrigeration unit capable of rapid, repeatable cooling to –50 °C without liquid nitrogen or auxiliary chillers. Its core sensing architecture utilizes medical-grade pressure transducers and high-stability thermal elements, delivering traceable accuracy even at near-threshold pressures (<5 mBar), where microstructural yield behavior dominates rheological response.

Key Features

• Integrated cryogenic cooling system enabling stable operation at –50 °C without external coolant sources
• Medical-grade pressure transducer with <1 mBar resolution and full-scale linearity certified per ISO/IEC 17025-accredited calibration protocols
• Thermally isolated test chamber with active PID-controlled temperature regulation (±0.3 °C stability over 30-min dwell)
• Touchscreen PLC interface with intuitive workflow navigation, real-time pressure/temperature trending, and on-screen contextual help
• Single-test-port configuration with three interchangeable collection vessels for efficient sample turnover and cross-contamination prevention
• Internal compressed-air generation system eliminating dependency on lab air lines or external regulators
• Ethernet connectivity supporting remote monitoring via dedicated iOS/Android application and integration into LIMS environments

Sample Compatibility & Compliance

The K95300 accommodates standard DIN 51805-compliant grease specimens applied uniformly onto a clean glass substrate using a calibrated spatula; bubble-free film formation is verified visually prior to insertion. It supports NLGI consistency classes 000 through 3 and is routinely validated for lithium-, calcium-, polyurea-, and clay-thickened formulations. All mechanical and electronic components comply with IEC 61000-6-2 (EMC immunity) and IEC 61010-1 (safety for laboratory equipment). Test reports generated by the embedded software include full audit trails—timestamped parameter settings, raw pressure/time datasets, operator ID, and environmental metadata—ensuring alignment with GLP and GMP documentation requirements. The system supports 21 CFR Part 11-compliant electronic signatures when deployed with validated user access controls and encrypted data storage.

Software & Data Management

The onboard software features a deterministic real-time operating environment running on an industrial-grade ARM-based PLC. Users configure test profiles—including target temperature, initial pressure, ramp rate (default 30 s/step), and termination criteria—via a hierarchical menu structure. Each run auto-generates a CSV-formatted dataset containing pressure, temperature, time, and derivative dP/dt values at 100 ms intervals. Export options include USB flash drive dump, network SMB share, or direct API push to enterprise data lakes. Historical runs are indexed by date, operator, and batch ID; search filters support ISO 17025-required traceability. Firmware updates are delivered via signed OTA packages with SHA-256 verification. Optional validation packages (IQ/OQ/PQ protocols) are available for regulated QC laboratories.

Applications

• Quality control of finished greases in OEM and additive manufacturing supply chains
• Formulation development for low-temperature automotive chassis and wheel-bearing greases
• Performance benchmarking against ASTM D1092 (cold-temperature pumpability) and ISO 6743-9 classification criteria
• Stability assessment of thixotropic recovery after thermal cycling (e.g., –40 °C → 23 °C → –40 °C)
• Regulatory submission support for EU REACH and EPA TSCA compliance dossiers requiring low-temperature rheological characterization
• Research into shear-induced structural breakdown and cold-set gelation kinetics

FAQ

What standards does the K95300 directly support?
DIN 51805 is the primary reference method; supplementary validation data exist for correlation with ASTM D1092 and ISO 2137 (cone penetration) at low temperatures.
Is external cooling infrastructure required?
No—the system includes a hermetically sealed, oil-lubricated scroll compressor and dual-stage evaporator enabling autonomous cooling to –50 °C.
How is measurement repeatability ensured across operators?
Standardized sample loading templates, automated pressure ramp sequencing, and integrated video-assisted training modules minimize procedural variability.
Can the instrument be integrated into a central lab automation network?
Yes—Ethernet port supports Modbus TCP and HTTP RESTful APIs for bidirectional communication with MES, SAP QM, or LabVantage platforms.
What maintenance intervals are recommended?
Compressor oil replacement every 24 months; annual recalibration of pressure and temperature sensors by Koehler-certified service engineers.