3-309. TACHOGRAPH REPLACEMENT (Continued).
D. READING TACHOGRAPH CHART.
The outer ring of the chart has markings for 24 hours.
on the chart by the markings happened at the time shown on
the outer ring of the chart. Also, each time the tachograph is
a small tic mark is put onto
the chart by each stylus.
(There is a stylus for vehicle speed, engine speed, and distance).
Next to the outer marks for time there is a band about 3/4" wide.
The stylus moving in this area records vehicle speed at any moment.
You can see at a glance if an operator has been speeding.
After the speed band, there is a narrower band about 1/2" wide.
Another stylus moves in
this area, recording engine RPM.
if the engine RPM have been too high. You can
whether the driver warmed up the engine before moving out.
this, compare RPM reading with vehicle speed.
The chart should
record the RPM for the proper number of minutes before vehicle
speed is recorded.
DISTANCE A third stylus moves in
the narrowest band, closest to the chart
moves away from the center
for 5 miles and
then toward the center for 5 miles.
In the chart shown, the vehicle did not move from midnight to about 5:37 AM.
Then the engine was started, run momentarily at about 1800 RPM, then idled at
600 RPM for six or seven minutes, accelerated 2100 RPM momentarily, then shut-
down at about 5:46. At 7:10 AM the engine was started again, idled for 22
minutes. At 7:32 it was moved out, attaining a speed of about 28 mph, then
stopped and idled for eight minutes. Then it moved out, accelerated to about
45 mph and did stop-and-go driving about 32 minutes, accelerating from 0 to
about 45 mph three times and traveling about 15 miles. At 8:11 it stopped,
having traveled about 15 miles, it idled for about 48 minutes and then was
shutdown at about 9 AM.