Valmet Valmet MCA, Installation & Owner'S Manual, Page: 35 / 66

9. Special Functions
The Special Functions menu contains the following
functions:
1 = C h e m i c a l c o m p
2 = T e m p e r a t u r e c o m p
3 = S e n s i t i v i t y c o r r
4 = R e c i p e s
9.1. Chemical compensation
Large fluctuations in chemical content may cause errors
in Valmet MCA consistency measurements. These er-
rors can be compensated for with chemical compensa-
tion based on microwave damping measurement.
You can use chemical compensation as described
in the following two sections.
Entering Laboratory Values
1. Take a sample as described in section 7.1.
2. Determine the sample’s consistency and its filtrate
conductivity at room temperature.
3. Go to the menu Enter Lab.
4. Press the Edit button, and enter the laboratory
consistency and filler information. Press the Enter
button to scroll the display down after the last line.
5. Select the chemical type with the up and down
arrow buttons. Enter the sample’s conductivity in
units mS/cm.
S a m p l e 1 2 . 0 8 - 0 4
M C A = 3 . 0 0 C s
L a b = 0 . 0 0
F i l l e r = 0 %
K a o l i n = 0 %
C a C O 3 = 0 %
T a l c = 0 %
T i O 2 = 0 %
C h e m = N a O H
M C A c o n = 2 . 4 0 m S / c m
L a b c o n = 0 . 0 0 m S / c m
F i l l e r s e n s = 1 . 0 0
%
% C s
If the conductivity meter shows results in units mS/m,
divide the result by 100, e.g. 550 mS/m = 5.5 mS/cm.
If the conductivity meter shows results in units
µS/cm, divide the result by 1000, e.g. 5500 µS/cm =
5.5 mS/cm.
If the conductivity meter shows results in units µmho/
in, divide the result by 2500, e.g. 25 000 µmho/ in = 10
mS/ cm.
Using Chemical Compensation
After you enter the laboratory values, go to Special
Functions menu and select 1 (Chemical Compensa-
tion). The following display appears:
Chem.comp = OFF
Comp. value = 0.00 %
MCA con = 0.00 mS/cm
Chem = NaOH
Lab cond = 3.4 mS/cm
Press the Edit button to make the cursor appear in
the Chemical Compensation field. The OFF text indic-
ates that chemical compensation is not in use. Use the
up and down arrows to change the text from OFF to
ON. Press Save, after which MCA begins using chem-
ical compensation.
The second line Comp. Value shows the chemical
compensation value, or the value that chemical com-
pensation subtracts from the measurement result. The
third and fourth lines show the chemical and laboratory
conductivity values entered by the user.
Installation & Owner’s manual OUL00298 V2.3 EN 35 Valmet Mircowave Consistency Transmitter