At first glance, it can be hard to tell one entrance mat from another. So how do you know which one does better than the next when it comes to capturing sand and dirt that will otherwise get tracked into a building?
The answer is: by measuring the mat’s performance. That’s why we’ve developed a proprietary method for doing just that. It uses four simple criteria to help you decide which types of entrance mat to install where, and then make recommendations to architects, specifiers, and installers.
Sand-absorption rate (SAR)
In principle, given a regular cleaning schedule, an entrance mat can scrape off up to two kilograms of sand for each square metre before it is fully saturated. In practice, though, the most a mat actually absorbs is between 70% and 95% of that amount.
The measure of how much sand gets past the mat is the building-soiling rate (BSR). The higher the SAR, the lower the BSR.
We have created three SAR performance categories:
1: less than 80%
2: 80 to 90%
3: 90% or higher
Cleanability rating (CR)
This measures how effectively a mat can be cleaned. Typical values range from 50% to 85%. The rest stays in the mat (see figure 1). And the more sand stays in the mat, the higher the wear and tear. That’s because grains of sand are actually sharp and damage the pile over time.
Carpet-soiling rate (CSR)
This is the third criterion. All the sand that stays in the mat after vacuuming (under a regular vacuum-cleaning schedule) eventually builds up to a saturation point. In figure 2, the blue line shows the amount of sand the mat holds before and after each time it is vacuumed. The black line indicates the average amount of sand that stays in the mat through successive rounds of vacuuming.
Optical-performance rating (OPR)
This is the fourth criterion. A mat cannot look its best if it contains a lot of sand. We have put the range of cleanliness, from utterly spotless to fully saturated with dirt, on a scale from 1 to 5, where 5 is the cleanest.
Turning to figure 2 again, we see from the example that the saturation level is set at 50 grams. In figure 3, the optical performance of this product is 4.5 out of 5 at 50 grams, which is very good: almost none of the sand in the mat at saturation level can be seen.
Of these four criteria, two are key: SAR and OPR. These are shown in our specification tables.
Working with these criteria allows us not only to verify the quality of what we produce, but to fine-tune the characteristics we want, working in a cycle of continual improvement.