Koehler K22752 Low-Temperature Kinematic Viscosity Tester

Overview

The Koehler K22752 Low-Temperature Kinematic Viscosity Tester is an engineered solution for precise determination of kinematic viscosity in petroleum and lubricant samples under sub-ambient conditions. Based on the capillary efflux principle defined in ASTM D445, the instrument measures the time required for a fixed volume of liquid to flow under gravity through a calibrated glass capillary tube at a tightly controlled temperature. Kinematic viscosity—expressed in mm²/s (cSt)—is derived from this efflux time and the viscometer’s calibration constant. The K22752 integrates a high-stability, low-temperature constant-temperature bath with advanced thermal management architecture, enabling reproducible measurements across critical low-temperature ranges used in engine oil specification (e.g., SAE J300), jet fuel certification (ASTM D1655), and cold-flow property evaluation of base oils and synthetic lubricants.

Key Features

• Two-stage compressor refrigeration system ensures stable operation down to –70 °C without cryogenic fluids or external chillers.
• Microprocessor-driven PID temperature control delivers ±0.1 °C stability, with traceable calibration to 0.01 °C resolution—meeting stringent requirements for GLP-compliant laboratories.
• Electrically driven, non-turbulent bath circulation maintains uniform temperature distribution across the full 14 L bath volume, validated per ASTM D445 Annex A1 for spatial uniformity.
• Dual-line digital display simultaneously shows setpoint and real-time bath temperature, minimizing operator interpretation error during method execution.
• Translucent acrylic bath cover with integrated viewing window enables visual monitoring of capillary filling, meniscus movement, and efflux events without compromising thermal integrity.
• Modular platform supports three operational configurations: manual (LKV3000), semi-automated (LKV4000 with keypad input of viscometer constants and timed efflux recording), and fully automated (LKV5000 with optical flow detection and programmable measurement sequences).

Sample Compatibility & Compliance

The K22752 accommodates standard Ubbelohde, Cannon-Fenske, and Ostwald-type capillary viscometers (including ASTM D445-specified sizes: 0.2–1.0 mm bore). It supports routine testing of crude oil fractions, diesel fuels, aviation turbine fuels, hydraulic fluids, gear oils, and biobased lubricants. All operating modes comply with ASTM D445 (Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids), including mandatory provisions for bath temperature uniformity, efflux time repeatability, and calibration traceability. The system architecture supports audit-ready documentation when paired with compliant laboratory information management systems (LIMS), and its deterministic timing logic aligns with FDA 21 CFR Part 11 data integrity expectations for electronic records.

Software & Data Management

While the base K22752 operates as a hardware-controlled benchtop unit, the LKV5000 configuration includes embedded firmware supporting programmable test sequences, automatic efflux time capture via optical beam interruption, and real-time calculation of kinematic viscosity using user-entered capillary constants. Data export is available via RS-232 or USB interface in CSV format, compatible with Koehler’s optional ViscoLink™ software suite for statistical analysis, trend reporting, and ASTM D445-compliant certificate generation. All firmware versions maintain full revision history, parameter change logs, and operator ID tagging—enabling compliance with ISO/IEC 17025 clause 7.7 (result reporting) and internal QA/QC traceability protocols.

Applications

• Low-temperature viscosity grading of multi-grade engine oils (e.g., 0W-20, 5W-30) per SAE J300.
• Cold-start performance assessment of automotive and industrial lubricants.
• Specification conformance testing for Jet A-1 and JP-8 fuels per ASTM D1655 and DEF STAN 91-91.
• Quality control of synthetic ester and polyalphaolefin (PAO) base stocks.
• Research into wax crystallization effects on flow behavior in waxy crudes and distillates.
• Validation of pour point depressants and viscosity index improvers under controlled thermal gradients.

FAQ

Does the K22752 require external cooling water or liquid nitrogen?
No. The integrated two-stage compressor eliminates dependence on auxiliary cooling media, reducing infrastructure requirements and operational complexity.
Can the same bath be used for both ASTM D445 and ASTM D7042 (HTHS viscosity)?
No. ASTM D7042 requires high-temperature, high-shear conditions incompatible with the K22752’s low-temperature bath design. It is purpose-built for kinematic viscosity per D445 only.
Is calibration verification supported out-of-the-box?
Yes. The system includes built-in reference thermometer ports and supports NIST-traceable RTD probes for periodic verification per ASTM D445 Section 7.2.
What safety certifications does the K22752 carry?
It complies with UL 61010-1 and IEC 61010-1 for electrical safety, and incorporates overtemperature cutoff, refrigerant leak detection, and door-interlocked compressor shutdown.
How is temperature uniformity validated across the bath volume?
Per ASTM D445 Annex A1, Koehler provides a certified uniformity map demonstrating ≤0.02 °C deviation across all four viscometer positions at –30 °C and –70 °C, included with each unit shipment.