Aztec ATS430 | Turbidity sensor
|
OI/ATS430–EN Rev. H 11
6.2 Sensor verification
6.2.1 Preparing the verification tool and locking the sensor
in place
The verification tool can be used to verify sensor operation as
an alternative to using formazin. Using the verification tool
eliminates the need to handle potentially hazardous chemicals
(formazin) during routine verification.
Referring to Fig. 6.1:
1.
Select a verification puck with the NTU value suitable for the
application – the NTU value is printed on puck label
A
.
2. Remove protective cap
B
from puck
C
.
3. Align slot
D
(opposite puck label
A
) with sprung ball
screw
E
located within the bore of the lower section of
verification tool
F
.
4. Press puck
C
into place taking care not to touch the upper
surface and confirm a puck of the correct NTU value has
been fitted – the NTU value of the puck is visible through
front aperture
G
.
5. Pour a few drops of coupling agent
H
onto the puck
surface, near the centre of the circle.
6. Ensure slider
I
is in the unlocked position.
7.
Insert sensor
J
into verification tool
F
and align the
(2 opposing) holes
K
with notch
L
on the verification tool
top cap.
8. Push sensor
J
down until the holes
K
in the sensor body
are within the top cap, then push slider
I
to the locked
position to lock sensor
J
in place.
9. Refer to Operating instruction OI/AWT440-EN and initiate a
verification routine.
10. When the verification routine is complete, carefully wipe
puck
C
and verification tool
F
clean, refit puck cap
B
and store all items into the case supplied with the kit.
IMPORTANT (NOTE)
— Ensure the verification tool carrier is kept clean and
any dirt is removed after each use.
— Ensure the sensor is clean of dirt and fouling prior to
insertion into the verification tool (step 7).
— Take care not to damage the surface of verification
pucks. When using the puck in locations where grit
or sand may be present, ensure the sensor is
thoroughly clean before inserting it into the
verification tool. Any debris on the front face of the
sensor will prevent the puck making full contact with
the sensing area and result in a reading error as well
as possible damage to the puck.
IMPORTANT (NOTE)
Sensors with accessories connected:
— sensor
J
is shown with a standard cable
attached. If accessories (such as dip pole, chain
adaptor) are connected there is no need to
disconnect them. Verification can be performed
with accessories in place. For flow cell mounted
sensors, unscrew the flow cell adaptor from the
sensor then slide it up the cable.
Aligning sensors fitted with wiper:
— orientate the sensor with the wiper blade to the
front (open cut-out) to ensure correct
alignment with the puck. This also ensures
correct alignment with the locking plate peg. To
avoid damage to the wiper arm, wiping is
disabled automatically while the sensor is
inserted in the verification tool.
IMPORTANT (NOTE)
When pushing the sensor into
the verification tool body (step 8), ensure the sensor
is inserted straight so that the sensor face is placed
directly onto the puck surface.
Fig. 6.1 Using the verification tool
Label on rear face of tool – shows
sensor fitting / preparation
Locked
Unlocked
Ensure the coupling
agent is applied near
the centre of the
circle. For the wiper
puck, this is near the
straight edge.
