Loop Installation; Dimension And Placement Of The Loop - Allmatic A1H-U Manual De Instrucciones

7. Loop installation

A proper installation of the loop in the road, is the single most important factor for achieving a reliable
detector system. Most detection issues are caused by improper loop installation. Please read the
guidelines below carefully to ensure best possible performance in the application.
If a new loop is installed in an existing application, it is recommended to remove any old loop wire
left in the ground.

7.1. Dimension and placement of the loop

The first thing to consider when installing a new loop is the dimension and placement. The dimension of
the loop is dependent on the road size and is normally rectangular in shape with chamfered corners.
The loop should be placed with approximately 30 cm (1 foot) distance to the edge of the road and
other road lanes. This helps to prevent false detections caused by traffic passing in adjacent traffic
lanes.
L11 L12 E1
R21 R22 R23
5 6
4 7 LOOP
3 8
2 9 RELAY 1
1 10
SENSITIVITY RELAY 2
45º
R11 R12 R13
A1 A2 E2
b
30 cm
1 foot
45º
To reduce stress on the cable and thereby prolong its service life, it is important to avoid sharp bending
of the cable. This is done by cutting a groove at 45 degree angles in each corner. To achieve optimal
signal conditions, the width of the loop (a) should be approximately the same as the width of the
vehicle. In most applications, the dimension of vehicles often varies, in this case it is recommended to
install a loop, which is wider than a typical vehicle and match the width of the road. It is possible to
detect vehicles with a narrow loop, but this reduces signal strength.
Track width
Excellent signal
Favourable
14
Rev.00 - 09.2021 | A1H-U Single Loop Detector | © 2021 | Allmatic
a
45º
30 cm
1 foot
45º
Good signal
Unfavourable
a
45º
b
30 cm
1 foot
45º
L11 L12 E1
R21 R22 R23
5 6
4
3
2
1
SENSITIVITY
45º
R11 R12 R13
A1 A2 E2
30 cm
1 foot
45º
Reduced signal
Unfavourable
7 LOOP
8
9 RELAY 1
10
RELAY 2