Acoustic SLAB

How does it work ?
One or more underground SLABS sensitive to micro-variations in pressure are used to detect footsteps. A timer system prevents overcounting if a person steps twice on the SLAB. For wide passages, the dimensions and spacing of the SLABS can count people walking alongside each other, while maintaining an accuracy of ± 5%.
Technical Characteristics



Acoustic slab

Weight: 4.5 kg (9.9 lbs)

Dimensions :

Length 50 cm (19.7')

Width 60 cm (23.6')

Thickness 1.6 cm (6.3')
Highly accurate counting of groups

Detects direction of movement

Completely undetectable

Low maintenance

10-year battery life

High-capacity memory (21 months)

Waterproof (IP 68)
Hidden from view
The Acoustic SLABsensor is specially designed to be completely undetectable once installed. Once buried, the Acoustic Slab sensor is completely hidden from view.
Natural soils

For hard-packed soil or soil susceptible to erosion, the SLAB can be delivered with a protective honeycomb overlay to stabilize the soil and prevent the SLAB from being uncovered.
Artificial grounds

For surfaces covered with asphalt or paving blocks, specific solutions such as loose ground kits or floating SLABS allow inconspicuous installation without sacrificing the sensor's accuracy.
The key points
Large width and high accuracy

In the case of wide paths, the size of the SLABS and the spacing between them make it possible to count several people at the same time while maintaining an accuracy of ±5%.


With two rows of SLABS, not only can the number of pedestrians be counted, but the direction they walk in can be measured as well.

Robust and battery-powered

Specially designed for outdoor use, the sensor and logger are sealed to an IP68 rating against dust, mud and water.
The robust sensor withstands occasional overrun by small maintenance vehicles.
The system runs on a 10-year battery (Bluetooth™ mode) and can store up to 21 months' worth of data (hourly records).
Examples of installation
Evaluation of the impacts of tourism


A dozen SLAB counters have been installed along the 250 km (155 mi) Cathar Trail in the upper Aude Valley. The count data has been compared with data from:

field surveys of visitors;

surveys of local accommodation providers (campgrounds, mountain huts, gîtes, hotels, etc.)

telephone or postal surveys;

panel discussions (academics, technicians, etc.)

local tourism promoters (sale of hiking guides, etc.).

Comparing this data with the count data logged by pedestrian, horse and MTB Eco-Counters has enabled to identify the social, media and economic impacts of the popularity of the Cathar Trail.
Management of visitors flows

Two car counters and around ten SLAB counters were installed at strategic points (parking lots, dams, lakes and other points of interest) on Mount Saint-Victoire in southern France in 2002.
The quantitative data logged at these points was combined with a large-scale qualitative study in 2009. The study revealed, among other things, that the flows of visitors had shifted and that areas that initially had not often been frequented y visitors had a much higher chance of being accessed. Measures were quickly taken to protect these areas from damage caused by the rising number of visitors. Signs and trail markers were also added to direct visitors along the right paths.