Determining Colour Range in Petroleum Products

Petroleum is used in the development of numerous products and applications. Refinement and quality control of these products all rely on colour analysis to meet regulatory standards for safety and quality. Image Source: Flickr user Steve Snodgrass

Colour is a key indicator of quality in petroleum-based products and developing a colour range is an important part of the refinement process. A colour range can often be used for monitoring contamination and quality control. Petroleum-based products make up a wide variety of manufactured goods; with consumers relying on colour for acceptability, it’s crucial to meet the quality standards of visual perception.

There are several test methods available for determining the colour of refined oils and these are necessary for addressing the use of petroleum within a variety of applications. From fuel sources to pharmaceuticals, colour analysis plays an important role in developing products that are high in quality and safe for use. Spectrophotometric determination and quantification of colour is commonly used for developing colour range measurements needed for monitoring variations in processing and meeting standardization requirements.

Saybolt and ASTM colour standards

The advanced refinement process for petroleum based product requires set measurements and colour range parameters. These guidelines are imperative in meeting standardization process regulations for ensuring product compliance, quality, and safety. The two colour scales primarily used for measuring petroleum products are the Saybolt and ASTM colour1. These systems use a colour range scale of liquid petroleum based on a range of lightness to darkness. Spectrophotometers employ a visual comparison method to quantify these variations in the colour range and visually match them with the appropriate number on the colour scale.

Spectrophotometry is the preferred method of analysis in ASTM and Saybolt colour scale evaluation for many reasons: instrumentation is both durable and portable, making it ideal for laboratory and manufacturing settings. This rapid and easy-to-use tool provides repeatable information that can be used to develop the colour range parameters needed to classify various petroleum-based products for specific application and usage.

Petroleum-based products require colour evaluation at every stage of production. From base or raw materials to final product evaluation, spectrophotometry plays an important role in quality control and standardization. Image Source: Flickr user woodleywonderworks

Applications of colour range measurements

In many cases, colour is “an indication of the degree of refinement of the material. When the colour range of a particular product is known, a variation outside the established range can indicate possible contamination with another product.”2. Colour range measurements can determine the colour of a “wide variety of petroleum products such as undyed motor and aviation gasoline, aviation turbine fuels, naphthas, kerosene, pharmaceutical white oils, diesel fuel oils, and lubricating oils.”3. Understanding and utilizing colour range measurement is critical for proper petroleum usage for chemical analysis in the petrochemical industry. Determining the purity of raw materials dictates the use of these materials, ensuring both safety and quality; thus, the right instrumentation is crucial for quantifying the colour range and meeting standards and regulations in the petroleum industry.

Pharmaceutical grade petroleum products require continuous monitoring for quality and purity analysis. Image Source: Flickr user Nina Nelson

Instrumentation and measurement procedures

Spectrophotometric determination of colour range requires various sample mediums based on petroleum product application and refinement stage. Instrumentation design to accommodate a variety of sample sizes and viscosities is important for developing the appropriate colour range scale, while still ensuring accuracy and ease of use. At HunterLab, our instrumentation is specifically designed for use in the petrochemical industry and we offer a variety of tools made specifically for these various applications. Whether you need easy access and large transmission cell holders or continuous flow monitoring, we have a spectrophotometer design for nearly any raw material or final product evaluation need. For more information on the latest technology in colour range in petroleum-based product measurement, please contact HunterLab today.