WEIGH IN MOTION |
Certification for WIM
Different situations require different scales and sensors for ensuring
over-loaded vehicles are prevented from damaging public roads. OIML
certification ensures the various systems are up to the required standard
Words | Jon Arnold, Intercomp, USA
Above: The
low profile and
lightweight LP788
Below: WIM strip
sensors installed
in the mainline
This past year has led to
additional certifications for
products manufactured by
Intercomp. The USA-based
company has offices in Europe,
Latin America, and Asia, providing
scales and sensors to their global
customer base.
Manufacturing portable static and
Weigh-In-Motion (WIM), and fixed
WIM scales and sensors for a wide
range of applications, Intercomp has
made design of products which pass
independent laboratory testing a
priority over the past few years.
These certifications enable users to
incorporate internationally certified
products for direct enforcement,
tolling by weight, pre-selection and
screening for enforcement, as well
as bridge and tunnel protection.
The products are developed
around strain gauge load sensing,
which is used in static truck
weighing for direct enforcement
and are viewed as the most accurate
means to weigh a vehicle.
Intercomp utilizes the highly
accurate technology which has been
developed for WIM use at both low
and high speeds. Strain gauge load
sensing and its inherent performance
characteristics include stability over
time and during changes in
temperature, which assists in
the certification of scales and
systems that incorporate the
scales and sensors.
140 Intertraffic World | Annual Showcase 2020
WIM strip sensors
Perhaps the most versatile weighing
sensor to achieve the certification,
Intercomp strip sensors obtained
OIML R134 approval up to mainline
speeds. OIML R134 is an
international WIM standard which
is widely accepted in many countries,
and specific regional or national
legislation typically refers to or
reflects R134 performance and
testing requirements.
Scales that are certified to
this standard can then be used in
a variety of applications that require
these performance certifications.
Installed in pairs in the pavement,
the strip sensors measure axle and
gross vehicle weights as well as
speed and axle spacing. Typical
installations include 2-8 sensors in
multiple rows of sensors depending
on the required accuracy, and
are available to be integrated to
a variety of different electronics
and software.
Unique among these types
of WIM sensors and scales,
the strip sensors are certified to high
speeds of 62 mph (100kmh) with two,
three, and four rows of sensors.
Installation is achieved with small
channels cut into the pavement, and
the minimal sensor depth and form
factor enables rapid installation in
a vehicle lane in a single day.
The sensors have an operational
speed range starting at 2mph
(3km/h) ranging up to typical
driving speeds that give increased
operational speed capability for use
in a variety of low, medium, and high
speed weighing applications.