NOTE
For reliable measurement, in particular when using the device to output measured
values, the laser needs to hit the object several times. Therefore, the object either
needs to be larger than the minimum object size, or both the device and the object
must not be moving.
3.6.9
Contamination measurement
The device has an front screen to protect it. This front screen can get dirty. Contamina‐
tion reduces the energy emitted and received by the laser beam. As a result, scanned
objects appear to have a lower remission than they actually have and, with a certain
level of contamination, it will no longer be possible to perform measurements. The
device has 6 of its own contamination sensors. Depending on the selected contamina‐
tion strategy, a certain number of these sensors is evaluated. The 6 contamination
sensors are divided up into 2 groups (3 + 3).
The contamination is therefore constantly measured by a separate system during
operation. A contamination warning is output first for the different degrees of con‐
tamination. If the front screen is not cleaned and contamination increases, then a
contamination error is output. In the case of the outputs, the
Device not Ready
function
responds and switches the outputs in the event of a contamination error. The device
continues to output measurement data. The contamination bit in the measurement
data telegram should be checked in this case (see Telegram Listing, part no. 8014631
at
).
Depending on the application in which the device is used, you can choose from differ‐
ent contamination measurement strategies.
SOPAS ET:
Project tree
,
LMS…
,
Parameters
,
Contamination Measurement
.
•
Deactivated: Contamination measurement is not carried out.
•
High availability: Contamination warning and contamination errors are only output
when the front screen is uniformly contaminated. This means that all 6 contamina‐
tion sensors must have reached the limit value for a warning or error.
•
Available: Contamination warning and contamination errors are output when the
front screen is partially contaminated.
•
Semi-sensitive: Contamination warning and contamination errors are output when
the front screen is partially and only slightly contaminated.
•
Sensitive: Contamination warning and contamination errors are output even when
there is just a little or local contamination.
NOTE
The cleaner the application environment is, the lower you can set the contamination
measurement sensitivity. If a high precision of the measured values is required, the
contamination measurement must be set to the most sensitive level.
Contamination warnings and contamination errors are displayed on the status indica‐
tors of the device
see "LED fault indicators", page 81
. You can also read out these
statuses via telegrams (see telegram list, part no. 8014631 under
).
A contamination error can also be reported on a digital output if it is configured as an
output for the
Device Ready
or
Contamination
status
see "Inputs and outputs", page 42
.
Table 8:
Contamination (flashing)
setting
Contamination
Digital output
No contamination
Deactivated
Contamination warning flashing
1 Hz 50/50 (on/off)
3
PRODUCT DESCRIPTION
24
O P E R A T I N G I N S T R U C T I O N S | LMS5xx
8013796/1ALS/2021-03 | SICK
Subject to change without notice
