Lovibond Surface Viewing System - Used Laboratory Equipment and New Lab Instrument Supplies, UK

Used Scientific Equipment

A Quick Visual Colour Check

The Lovibond® Surface Viewing System (SVS) is ideal for the many applications in colour analysis where it is adequate or even advantageous to make a quick visual comparison between a sample and a standard of the target colour. It is a simple yet effective visual instrument for grading and quality control of surface colours which enables the user to compare the light reflected from the sample with precalibrated colour standards under standardised lighting conditions. The SVS takes advantage of the high sensitivity of the human eye to colour differences, allowing a pass or fail decision to be made very quickly; operators can see immediately if a sample differs from the target colour and whether that difference is just noticeable or significant.

Use of the SVS involves the development and manufacture of customised coloured glass filters which are matched by Tintometer to samples provided by the user - usually representing the ideal colour and acceptable colour limits or a series of product related colours for quality control purposes. Up to 9 individual glasses are housed in a Lovibond test disc which slots into the SVS for visual matching against sample colours.

The SVS consists of a standardised lighting unit to ensure uniform lighting conditions for consistent and accurate grading, topped by a visual comparator instrument for matching the sample colour with the glass filters. The sample is placed in the lighting unit, then observed through the comparator which has two overlapping fields of view so that the product and the glass filters (backed by a white reflective surface) are observed side by side, suitably illuminated. The colour standards are varied by rotating the disc, allowing the user to compare the colour of light which is reflected from the sample with that transmitted through the filters, until a colour match is obtained.

For samples with an irregular surface (and therefore variable colour appearance due to dips, reflections and shadows) or for samples with variations in colour throughout the product, the SVS is available with viewing optics which diffuse the surface of samples. The diffusing optics allow users to view a sample of uniform appearance which represents an overall impression of colour given by the product. Examples of products which can be graded for colour using the diffusing optics include gels containing bubbles,