English
Finger characteristics
Before deciding for one or more
ngers, you should note a number
of points.
Fingertips with a large number of •
injuries, scars or an unclearly dened
structure are less suitable as a user
nger.
Where ngers are relatively thick, •
use the smallest ngers on the hand,
i.e. the ring nger or small nger.
However, if the ngers are very •
small, for instance in the case of chil-
dren, the thumb should be used.
In right-handed people, the nger-•
tips of the left hand are less dam-
aged than in left-handed people and
vice-versa.
At least 2 ngers should be •
scanned in per person, ideally one
from each hand, in order to have
an alternative in case of injury to a
nger or a whole hand.
Where the number of people is •
limited, it makes sense to work with
a higher number of ngers, as at the
beginning it is possible to nd out
the preferred nger.
Optimum nger guidance
The ngerprint module uses only
the biometric data of the ngertips
for personal identication. Reliable
operation is guaranteed provided
the following conditions are met.
Using the module calls for some •
practice. Experience has shown that
recognition reliability increases with
frequency of use. We consequently
recommend you to practice correct
utilization before scanning in your
ngerprint.
Stand in an ergonomically com-•
fortable position relative to the
sensor.
Stretch out the nger you wish to •
scan in.
Draw the nger at over the •
sensor at around the last nger joint.
Exert a light pressure on the •
sensor.
Ensure that you move the nger in •
as straight a line as possible, without
„snaking“. Avoid hesitating while
moving the nger if possible.
Do not move the nger too fast •
or too slowly over the sensor. The
process should be completed within
a second.
For identication, pull the nger •
over the sensor in the same way as
when reading in the ngerprint.
Read in ngerprints
Fingerprint scanning starts automati-
cally, as soon as the upper section of
the nger is drawn over the sensor
in an even movement. The best
results are obtained by placing the
nger at in the nger recess at the
start of the downward movement
and laying the upper joint of the
nger section at the height of the
sensor (see Fig.1).
The sensor generates three pictures
when scanning in the ngerprint,
and searches for characteristic
features. The best of the pictures is
led in the internal database. If the
characteristics have been successfully
detected, the ngerprint is saved.
Causes of faults
Dirty ngers can have a negative •
impact on the recognition rate.
Injured ngers can have a nega-•
tive impact on the recognition rate,
which is why we recommend
teach-in of at least 2 ngerprints per
person.
Wet or moist ngers can have a •
negative impact on the recognition
rate.
Fingerprints of children can be •
recognized, depending on build
and motor function, from around
6 years. Practise operation of the
sensor together with your child.
Dry ngers, e.g. when handling •
solvents, can have a negative impact
on the recognition rate.
Swollen ngers, for example after •
soaking, can have a negative impact
on the recognition rate.
Finger is drawn over the sensor at •
a too steep angle and does not lie
ush on the surface (Fig. 2).
