How Carpet LRV Testing Works: A Simple Guide

At  Heckmondwike, we’re committed to creating high-quality carpet solutions that meet the practical needs of designers, architects, and facility managers. One of the key specifications often requested during product selection is LRV. But what exactly does that mean and how do we test it?

In this guide, we’ll walk you through how we determine the LRV of our carpet products, why it matters, and how this simple yet important measurement helps inform everything from lighting design to accessibility compliance.

If you’re new to the concept of LRV or want to learn more about how it impacts interior design decisions, check out our previous blog: Getting LRV and Colour Contrast Right in Floor Design.

Why Testing Matters for Carpets

Carpets are unique among floor coverings because their texture, pile height, and fibre type can significantly affect how light is reflected. Two carpets with the same colour may have different LRVs simply due to differences in surface texture or fibre construction.

That’s why accurate LRV testing is essential; it goes beyond just analysing colour. It measures how light interacts with the actual material. This is particularly important in environments where visual contrast is required, such as between floors and stairs.

The British Standard for Measuring LRV

LRV testing in the UK is governed by BS 8493:2008+A1:2010, which provides the standard method for measuring the LRV of surfaces, including carpets and other floor coverings.

Here’s a breakdown of how the process works:

1. Sample Size Requirements

To ensure accurate and consistent results, the test requires a minimum sample size of 450mm x 450mm. This allows enough surface area to account for the variation in texture, pattern, and fibre direction, especially important in carpets.

2. Grid-Based Testing Across 9 Points

The 450mm x 450mm sample is divided into 9 equal grid sections, each measuring 150mm x 150mm. A precise LRV reading is taken at specific points across the grid, resulting in 9 measurement points across the entire sample.

3. Using a Spectrophotometer

The sample is tested using a device called a spectrophotometer, which measures how much light is reflected off the surface.

4. Rotating the Sample for Consistency

To account for texture direction and surface variation, the sample is then rotated 90 degrees and measurements are repeated at each rotation. This process is done four times in total (0°, 90°, 180°, and 270°), capturing how the carpet reflects light from different angles.

5. Calculating the Final LRV

Each individual measurement is recorded and the average of all readings is calculated to determine the final LRV for that carpet sample.

Trust in Every Measurement

LRV testing may sound highly technical but understanding the basics ensures better outcomes in product development, specification, and inclusive design. At Heckmondwike, we follow the British Standard to the letter, so you can trust the data behind every surface.

Want to know the LRV of one of our carpet products? Download our brochure here

Have questions about LRV testing or need more info? Get in touch with our expert technical team today