Falsification and Irregularities.

TM 9-2320-211-20-3-2

(1) General. Some recordings on the chart fields may not be able to be read

from the examples given so far. The reasons could be the driver may have done

something to the tachograph to hide the true recordings or the tachograph may be

broken. The tachograph was built so any readings that record on the chart can be

read.

The tachograph has a lock and key and a knife-type pin on the door of the instru-

ment. When the door is closed, a hole is punched in the chart. This arrangement

will let only authorized personnel see the chart.

Taking off the speedometer or tachometer drive shafts makes the styluses draw base

lines only, but the stop and go stylus still records and shows the truck was driven.

Putting a weight or a rubber band on the speed stylus will record and show some-

thing was done on it. Bending the stylus will make it record below zero when the

truck is stopped. The recordings cannot be taken off the chart. Grease can be

washed off the chart but the readings will still be able to be read. False recordings

are rare. The following examples show what to look for if any false readings show on

the chart.

(2) Lowered speed.

(a) Problem. The speed stylus records the base line lower than what

it should be.

(b) Cause. The speed stylus was bent down so the recording on the

chart will show the truck was going slower than it really was. (See fig. 20-18.) To

find the true speed of the truck, add the lower base line reading to the recorded

reading. The tachograph will have to be adjusted so it will read correctly.

Figure 20-18. Speed Stylus Bent to Simulate Lower Speeds