SICK DUSTHUNTER C200 - Calibration for Dust Concentration Measurement; Calibrating Dust Concentration Measurement Based on Extinction

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8011952/YWL2/3-0/2016-08| SICKOPERATING INSTRUCTIONS | DUSTHUNTER C200
Subject to change without notice
4 START-UP AND PARAMETER SETTINGS
4.4.7 Calibration for dust concentration measurement
For exact dust concentration measurement, the relation between the primary measured
variables transmission (→ extinctioin) or scattered light intensity and the actual dust
concentration in the duct must be established. To do this, the dust concentration must be
determined based through a gravimetric comparison measurement according to
DIN EN 13284-1 and set in relation to the values measured at the same time by the
measuring system.
Steps to be carried out
4.4.7.1 Calibrating dust concentration measurement based on extinction
▸ Select device file “MCU”, set the measuring system to “Maintenance” mode
▸ Enter the Level 1 password (see “Password and operating levels”, page 84).
▸ Select the “Configuration / IO Configuration / Output Parameters” directory (see “SOPAS
ET menu: MCU/Configuration/IO configuration/Output Parameters”, page 71) and
assign the “Extinction” measured variable to an analog output.
▸ Estimate the measuring range required for the dust concentration in operational state
and enter this in the
“Analog Output 1 (2/3) Scaling” field assigned to the selected
analog output for output of the extinction.
▸ Deactivate “Maintenance” mode.
▸ Carry out the gravimetric comparison measurement according to DIN EN 13284-1.
▸ Determine regression coefficients from the mA values of the analog output for
“Scattered light intensity” and the actual dust concentrations measured gravimetrically.
c: Dust concentration in mg/m³
K2, K1, K0: Regression coefficients of the function c = f (I
out
)
I
out
: Current output value in mA
Ext: Measured extinction
LZ: Live Zero
MBE: Defined upper range limit value
(value entered for 20 mA;
normally 2.5 x fixed limit value)
▸ Enter the regression coefficients
There are two options:
– Direct input of K2, K1, K0 in a measured value computer.
NOTE:
Carrying out a gravimetric comparison measurement demands special knowledge that
cannot be described in detail here.
cK2I
out
2
⋅ K1 I
out
⋅ K0++=
(1)
I
out
LZ Ext
20mA LZ–
MBE
-----------------------------
⋅+=
(2)
NOTICE:
After calibration, the regression coefficients set in the sender/receiver unit and
the measuring range set in the MCU may not be changed anymore.
On the LC-Display (option), the dust concentration is shown in mg/m³ as
uncalibrated value.