SICK DUSTHUNTER C200, Installation Operation & Maintenance

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15 8011952/YWL2/3-0/2016-08| SICK O P E R A T I N G I N S T R U C T I O N S | DUSTHUNTER C200
Subject to change without notice
PRODUCT DESCRIPTION
2
Zero value measurement
The sender diode is switched off for zero point control so that no signal is received. This
means possible drifts or zero point deviations are detected reliably in the overall system
(e.g., due to an electronic defect). A warning signal is generated when the “zero value” is
outside the specified range.
Control value measurement (Span test)
Sender beam intensity changes between 70 and 100% during control value determination.
The light intensity received is compared against the standard value (70%). The measuring
system generates an error signal for deviations greater than ±2%. The error message is
cleared again when the next function check runs successfully. The control value is deter-
mined with high precision through statistical evaluation of a high number of intensity
changes.
For scattered light measurement, the value calculated theoretically (70%) is output for very
low dust concentrations (< approx. 1 mg/m³).
Contamination measurement
The glass panes positioned in the sender beam during normal measurement are swiveled
away during contamination determination (staggered for sender/receiver unit and
reflector/scattered light receiver). The contamination value is determined from the values
measured thereby and the reference values determined during every scaling process (
see
“Scaling the measuring system for transmission measurement”, page 63 ). The regular
measured values are reduced by the contamination value which fully compensates any
contamination that occurred.
Fig. 4: Contamination measurement principle (on both sides)
A value between live zero and 20 mA which is proportional to the contamination is output
on the analog output for contamination values < 40% (standard setting); when this value is
exceeded, the “Failure” status is output (on the analog output the set error current;
see
“Factory settings”, page 69 , see “Setting the analog outputs parameters”, page 71 )




Sender/receiver unit

Reflector

Pivoted shutter
●
The contamination limit value can be freely configured when the measuring system
is operated according to the European standard (
see “Entering application-specific
parameters”, page 64 ).
●
The contamination limit value for “Warning” is always 10% below the value for
“Failure”.
●
In operation according to the EPA standard, the contamination limit value for
“Warning” is set fixed to 3% and the value for “Failure” to 4%.