9
1.7.2 Stand Release (Raise & Lowers Stand)
The Stand Release button on the left hand side
of the enclosure is used to raise and lower the
LCA so that a sample beaker can be placed
under the sensor.
1.7.3 Probe and Piston
The probe and piston are both made of durable
Delrin plastic. These are critical components of
the LCA which produce the streaming current
reading. Proper care and inspection of these
parts is important to maintaining accurate charge
measurement results. Refer to maintenance
instructions in this manual for proper cleaning and
care of these parts.
1.7.4 Beaker (Optional)
Beakers are not supplied with the LCA but can be
ordered with the unit if desired. Various size
beakers can be used with the LCA. The smallest
beaker is a 250 mL and the largest size beaker
that is typically recommended is 2,000 mL.
Round or square beakers, glass or plastic, are
fine to use.
1.7.5 Magnetic Stirrer and Stir Bar
The LCA is supplied with a magnetic stirrer and
stir bar. The adjustable height of the LCA allows
for other magnetic stirrer make & models to be
utilized if desired.
1.7.6 Coagulant / Polymer Titrant Container
Models LCA-2 and LCA-3 come equipped with a
250 mL Nalgene Titrant Container for coagulant
(e.g. Alum, Ferric) or polymer (e.g. Dadmac).
This titrant container is located on the left side.
The coagulant or polymer needs to be diluted
down into a 1% (or less) solution.
1.7.7 Acid / Base Titrant Container
The LCA-3 has an additional titrant container on
the right side that is to be filled with the
appropriate acid or base solution. The acid or
base titrant must be diluted (typically 1% or less)
and compatible (in the diluted form) with the
following materials: POM, PTFE, FKM. Acetic
acid is usually recommended when pH reduction
is required prior to charge titration (typically
required for higher alkalinity samples when using
coagulants like alum, ferric, or low basicity PACl).
A base like sodium hydroxide is recommended
when pH needs to be raised during the titration to
maintain optimum pH. The raising of the pH
during the charge titration may be required on
lower alkalinity / lower pH waters, especially
when feeding acidic coagulants (e.g. alum or
ferric).
1.7.8 Coagulant / Polymer Titrant Pump
The coagulant titrant pump (also referred to as
the charge titration pump) is located to the left of
the probe on models LCA-2 and LCA-3. Each
stroke of the pump delivers approximately 50 µl
of coagulant. This pump cannot be used to titrate
neat (undiluted) coagulants.
1.7.9 Acid / Base Titrant Pump
The acid/base pump (also referred to as the
buffer pump) is located to the right of the probe
on model LCA-3. Each stroke of the pump
delivers approximately 50 µl of buffer solution.
This pump cannot be used to titrate neat
(undiluted) buffers.
1.7.10 pH electrode and Temp probe
The pH electrode and temperature probe is
optional on models LCA-1 and LCA-2, but comes
standard on LCA-3 They are located to the right
side of the LCA’s probe. The pH probe is
connected to a BNC male connector for easy
removal. The temperature probe is permanently
affixed to the LCA and cannot be removed
(except by factory). The pH reading is very
important to obtaining accurate charge readings
and coagulant dosage determination on the LCA.
The probe should be kept wet at all times and put
into pH 7 buffer solution for short term storage.
Place probe in KCl storage solution for longer
term storage. Handle carefully to avoid dropping
and damaging the probe.
