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ROADMASTER -IRITESTER is a device used to measure road
roughness, based on the IRI Measuring Principle developed
by the World Bank. ROADMASTER is a separate device
consisting of an accelerometer, an odometer or a pulse
detector, the necessary electronics and a Laptop or
Notebook PC. It is easily installed in practically any
vehicle: a car, a van or a truck.
ROADMASTER can be provided with a Differential or
ordinary GPS device and the information on the location
(latitude and longitude or x-y- coordinates) can be
expressed together with the IRI values, if desired.
Measuring principle
An accelerometer installed on the rear axle near the
right wheel (and the right wheel path) measures its
vertical acceleration. By using double integration this
is converted to vertical movements of the rear axle and
thus to the longitudinal profile of the road surface
within certain wave lengths.
The longitudinal road profile is used as a input in
the IRI equations. The driven length is measured from the
pulses from the speedometer electronics of the vehicle or
in the case of a mechanical (wire) odometer a special
pulse detector is installed between the gear box and the
odometer cable.
As a result an IRI value is calculated for each 100
m.
As an option ROADMASTER can be provided with a GPS
device with or without differential correction.
ROADMASTER can be calibrated against the known road
profile or Golden Car. In practice we have found out that
ROADMASTER results typically differ less than 5 to 10 %
from an accelerometer-laser instrument based Road Monitor
System which is used in Finland.
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