Connecting The Conductivity Sensor; Connecting The Ph Sensor - Martek MARK 22 Operation Manual

Each sensor input connector is clearly
marked with the type of sensor that should
be connected to it. The connector labeled REC
is for the recorder cable. Below the REC con-
nector is the battery charger input jack plug.
3.3.1 Connecting the Conductivity
Sensor
To connect the Martek conductivity ref-
erence cell, remove the dust caps from the
connectors labeled TEMP and COND and
connect the appropriately marked cables of
the reference cell to the Mark 22. Make sure
the correct cable is inserted into the correct
connector ( the cable identification labels are
located just below the reference cell plugs ) .
To connect any other conductivity refer-
ence cell, connect the Conductivity Intercon-
nect Cable to the Mark 22 connector marked
COND. Then connect the leads from the ref-
erence cell to the red and black banana plugs
according to the manufacturer's instructions.
When connecting any senors to the
sample line, care should be taken to avoid
any air from entering into the line. The in-
trusion of carbon dioxide into the sample can
cause low pH values, erratic conductivity
measurements , and fluctuating temperatures
during measurement.
The Martek Conductivity Reference Cell
comes with its own integral flow chamber.
The 1/4 inch stainless steel tube fittings pro-
truding from the cell can be used with heavy
wall tygon tubing. It makes no difference
which end is the inlet or the outlet. A mini-
mum flow of 50 ml/minute is recommended
to prevent bubbles from adhering to the in-
side of the cell. After the cell has been con-
nected, a sharp rap to the sensor will dislodge
any trapped air bubbles. For best results, the
sensor should be hung vertically with the
outlet at the top.
Martek Instruments, Inc.
SPECIFICATIONS AND SETUP - 3
3.3.2
To connect the Martek pH sensor ( p/n
182-245 ), remove the dust cap from the Mark
22 connector marked pH. Insert the plug of
the BNC pH adaptor cable (P/N 603052) into
the connector. Finally, connect the plug from
the pH sensor to the socket of the adaptor
cable.
To connect a pH sensor from another
manufacturer, the sensor cable must be ter-
minated with a BNC-style connector.
low the same steps taken to connect a Martek
pH sensor to the Mark 22 Calibrator.
The pH sensor should be immersed in a
flowing water stream which has not been
exposed to air. The assembly drawing in Fig-
ure 3.2 illustrates a complete layout of the
pH Adapter Plug Assembly. If the Stainless
Steel Flow Chamber (P/N 180-51) and the
pH Plug Adapter (P/N 180-51A) have been
purchased with the Mark 22, the following
procedures should be followed:
A ) Connect the temperature cable to the BNC
connector of the Adapter Plug.
B ) Remove the black plastic pH sensor re-
tainer from the pH Plug along with its
rubber O-ring. Remove the protective cap
or soaker bottle from the pH electrode
and carefully slide the retainer, then the
O-ring, over the pH electrode and screw
the threaded cap of the electrode into the
retainer. Carefully screw the retainer back
into the pH Plug until secure.
C ) Remove the plastic locking nut from the
Stainless Steel Flow Chamber and care-
fully insert the pH Adapter Plug into the
Flow Chamber until it rests flush with the
top of the chamber. Slide the locking nut
over the pH sensor and temperature
cables and screw it firmly to the cham-
ber.

Connecting the pH Sensor

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