The Dutch Floor Testing Company conductssurface roughness measurements or skid resistance measurements by means of the SRT-Method of among other things wearing courses in the infrastructure, such as bridge decks and bicycle paths.  

Wearing courses may cause nasty falls, accidents or slips with far-reaching medical and financial consequences. Often this is due to the fact that surfaces are too slippery and/or they are soiled. Do you suspect that your wearing course is not safe or do you wish to be absolutely certain that your wearing course is safe enough:  The Dutch Floor Testing Company measures the surface roughness or skid resistance of almost all floors.  

Measuring method: SRT NEN-EN 13036-4 
Measuring instrument: Pendulum Skid Resistance Tester (SRT tester). 
Slider: 57 
If necessary, the measuring results will be adjusted by a factor taking into account the actual temperature at the time of the measurements.  

The measurements are carried out on a wet surface. This may be moisturised in advance. 

Type of surface: metal, synthetic, concrete, asphalt, tiles, wood, wearing courses. 


At each location, the instrument is checked by means of a zero measurement, and adjusted. Several measurements are carried out. As soon as the measured values are relatively constant, 5 measured values are recorded. In addition, the temperature and the type of surface are recorded.  

The average of the 5 measured values is the measured value, which, if required, is adjusted by a factor due to the actual temperature at the time of the measurements. This is described in NEN-EN 13036-4. 


Of road markings: 
To test the skid resistance of markings, the Standard RAW Provisions 2005 

(Standaard RAW Bepalingen 2005) 
distinguish various categories, depending among other things on the marking’s layer thickness.
A marking with a layer thickness < 0.5 mm must meet category S2 (SRT ≥50)  
A marking with a layer thickness ≥ 0.5 mm must meet category 3 (SRT ≥55).  
A marking with a so-called improved retroreflective effect under wet circumstances (such as a profiled marking) must meet category S1 (SRT ≥ 45).