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8012428/YWL2/3-0/2016-08| SICKO P E R A T I N G I N S T R U C T I O N S | DUSTHUNTER T
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
variable transmission and the resulting calculated measured variable extinction and the
actual dust concentration in the duct must be established. To do this, the dust concen-
tration must be determined based through a gravimetric comparison measurement
according to DIN EN 13284-1 and set in relation to the extinction values measured at the
same time by the measuring system.
Steps to be carried out
▸ Select device file “MCU”, set the measuring system to “Maintenance” mode
▸ Enter the Level 1 password (see “Password and operating levels”, page 86).
▸ Select the “Configuration / IO Configuration / Output Parameters” directory (see “SOPAS
ET menu: MCU/Configuration/IO configuration/Output Parameters”, page 76) 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
“Extinction” 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 uncali-
brated value.
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