Evoqua WALLACE & TIERNAN MFC, Instruction Manual

Page: 61 / 268

MFC
Functions
4.
61
Membrane sensor for chlorine
dioxide CD7
The CD7 membrane sensor enables the chlorine dioxide content
in all types of water to be determined selectively, also in high-purity
water (LF > 1µS/cm), without cross-sensitivity to chlorine, bromine
and hydrogen peroxide, but with cross-sensitivity to ozone and
peracetic acid. The sensor demonstrates no pH value dependency
(see "Technical data“) and is therefore very suitable for water with
various pH values.
Commissioning
Caution!
The electrode fingers (D) and membranes (G) are extremely
sensitive! Do not touch, soil or damage! Before unscrewing the
filled membrane cap (E), push the elastomer seal (H) to one side
to permit the inflow of air through the vent (F) underneath it (at the
cap label)! Otherwise, the membrane (G) may be damaged due to
the development of underpressure. Do not remove the light
yellowish-gray deposit of the reference electrode (K) or wipe it in
the direction of the gold working electrode (J)!
Flush eyes and skin immediately with water after contact. Rinse
away spilled electrolyte with water.
1 Screw off the membrane cap (E) from the electrode shaft (B)
and fill with the included gel electrolyte up to the top brim.
2 Rub gold working electrode (J) with the included lapping paper
(special emery). To do this, lay the lapping paper on a paper
towel, take hold of a corner, and using the tip of the vertically-
held electrode shaft (B), slide it once or twice over the rough
side of the lapping paper.
3 Check whether the elastomer seal (H) completely closes the
valve opening (F).
4 Then screw the filled membrane cap (E) slowly (by hand) back
onto the the electrode shaft (B).
Please note
As the excess electrolyte escapes through the valve opening (F)
under the elastomer seal (H), do not clamp it shut and do not press
it onto the elastomer seal (H).
5 Rinse off the escaped electrolyte with water.
Please note
The membrane cap (E) must be completely screwed (hand-tight)
onto the electrode shaft (B), so that no gap remains between the
two! After a run-in period of about one hour, the membrane sensor
is sufficiently run-in for an initial calibration to take place.
Calibration should be repeated after one day.
A
D
E
G
H
J
K
B
F
I
C
W3T164493