Koehler K13150 Saybolt & ASTM Automatic Colorimeter

Overview

The Koehler K13150 Saybolt & ASTM Automatic Colorimeter is a precision-engineered instrument designed for objective, reproducible color assessment of petroleum products in accordance with internationally recognized standard test methods—including ASTM D156 (Saybolt Color), ASTM D1500 (ASTM Color), and ASTM D6045 (Automated ASTM Color). It operates on the principle of filtered photometry using a fixed set of 16 calibrated interference filters spanning the visible spectrum (420–710 nm), enabling direct correlation to standardized color scales without subjective visual evaluation. The instrument employs a stable 5 V/10 W tungsten-halogen lamp as its light source and conforms to CIE 1931 2° standard observer geometry under C-illuminant conditions. Engineered for continuous 24/7 operation in both QC laboratories and production environments, the K13150 delivers traceable, operator-independent results—critical for regulatory compliance, batch release, and process control across refining, lubricant formulation, and petrochemical manufacturing.

Key Features

• Simultaneous support for Saybolt and ASTM color scales per ASTM D156, D1500, and D6045 protocols
• 16 pre-aligned, NIST-traceable interference filters with 20 nm spectral bandwidth for high-fidelity spectral sampling
• Optical path length adjustable from 0.1 mm to 153 mm (0.004″–6″), accommodating low- and high-absorbance samples including fuels, distillates, lubricating oils, waxes, and solvents
• High repeatability: chromaticity coordinates (x,y) ±0.0002; transmittance ±0.25%; Saybolt units ±1—validated per ASTM E259 and ISO 5725
• Self-diagnostic capability with built-in reference checks using certified Saybolt filter standards included with the system
• Rugged textured epoxy-coated steel enclosure resistant to hydrocarbon solvents, acids, and cleaning agents commonly used in petroleum labs
• 240 × 128 pixel backlit LCD display with intuitive menu navigation and audible keypress feedback for glove-compatible operation
• RS232 serial interface supporting direct connection to LIMS, SCADA systems, or thermal printers for audit-ready data export

Sample Compatibility & Compliance

The K13150 is validated for use with transparent to semi-transparent liquid petroleum products—including gasoline, kerosene, diesel fuel, naphtha, white oil, mineral seal oil, paraffin wax melts, and aromatic hydrocarbon streams. Sample cells are compatible with standard 10 mm, 20 mm, 50 mm, and 100 mm pathlength cuvettes (quartz or borosilicate), with optional custom cell holders available for non-standard geometries. All measurements comply with the metrological requirements of ASTM D1500 and D156, including spectral bandpass tolerance, illuminant spectral power distribution, and geometric constraints on beam divergence and detector field-of-view. The instrument meets CE marking requirements for electromagnetic compatibility (EMC Directive 2014/30/EU) and low-voltage safety (LVD Directive 2014/35/EU). While not inherently 21 CFR Part 11 compliant, its RS232 output supports integration into validated electronic record systems when paired with appropriate audit-trail software.

Software & Data Management

The K13150 operates autonomously via its embedded firmware but enables full data traceability through its RS232 interface. Raw spectral transmittance values, calculated color indices (Saybolt, ASTM, CIE x,y,Y), and measurement metadata—including date/time stamp, operator ID (via manual entry), pathlength, and filter identification—are transmitted as ASCII-formatted strings. These outputs integrate seamlessly with laboratory information management systems (LIMS) and statistical process control (SPC) platforms. Optional Koehler-provided terminal emulation software allows real-time monitoring, batch logging, and report generation in CSV or PDF format. All data exports include instrument serial number, calibration status flag, and pass/fail indication against user-defined specification limits—supporting GLP and GMP documentation requirements.

Applications

• Quality control of finished fuels and intermediates during refinery operations
• Monitoring oxidation stability and degradation onset in turbine oils and hydraulic fluids
• Specification conformance testing for commercial lubricants per API, SAE, and OEM standards
• Color grading of specialty solvents and process streams in petrochemical synthesis
• Stability assessment of paraffin and microcrystalline waxes under thermal aging protocols
• Raw material acceptance testing for feedstocks entering hydrotreating or dewaxing units
• Supporting root-cause analysis in off-spec product investigations where color deviation correlates with contamination or additive depletion

FAQ

Does the K13150 require annual recalibration by the manufacturer?
No—routine recalibration is not required if operated within specified environmental conditions (15–30 °C, <80% RH) and maintained per Koehler’s Preventive Maintenance Guide. However, users must perform daily verification using the supplied Saybolt reference filters and document results per internal QA procedures.
Can the K13150 measure opaque or turbid samples?
No—it is designed exclusively for transparent or translucent liquids meeting ASTM clarity criteria. Hazy or particulate-laden samples must be pre-filtered (e.g., through 0.8 µm membrane filters) prior to analysis to avoid scattering artifacts.
Is the instrument compatible with modern Windows OS versions for data capture?
Yes—when connected via RS232-to-USB adapter, the K13150 functions with standard terminal emulators (e.g., PuTTY, Tera Term) on Windows 10/11, macOS, and Linux. Koehler does not provide native GUI software, preserving platform neutrality and long-term interoperability.
What is the expected lifetime of the halogen lamp?
The 5 V/10 W tungsten-halogen lamp has a rated service life of ≥2,000 hours under continuous operation. Replacement lamps are field-serviceable and do not require optical realignment.
How does the K13150 handle temperature-dependent color shifts in viscous samples?
The instrument does not incorporate sample temperature control. Users must condition samples to 25 ± 0.5 °C (per ASTM D1500) using external thermostatted baths and verify temperature immediately before loading to ensure method compliance.