2
2 - OVERVIEW
Martek Instruments, Inc.
2.0
O
PERATIONAL
O
VERVIEW
A short description of the different fea-
tures of the Mark 22 is given below. Abbre-
viated instructions are provided for review
of the connections of the conductivity, tem-
perature, and pH sensors and the battery
charger. A description of the operational fea-
tures provided by the EIGHT keys on the
front panel is also presented. For more de-
tailed information on operation and calibra-
tion procedures, refer to the appropriate
chapters within the Manual.
1. Connect the Martek conductivity refer-
ence sensor to the connectors labeled
"COND" and "TEMP" on the side of the
Mark 22 readout module.
2. Connect the pH sensor to the connector
labeled "pH" on the side of the Mark 22
readout module. The temperature from
the Martek conductivity reference sensor
also provides the temperature for com-
pensation of the pH measurement. If the
Martek conductivity reference sensor is
not used, you must use the separate tem-
perature sensor located on the pH plug
(P/N 180-51A) or the dip-style tempera-
ture sensor (P/N 182-24T).
NOTE: If the pH sensor is not being used, the
shorting plug on the Mark 22 readout module
must be connected to the pH input connector.
This plug connects the input to the pH circuit to
analog ground allowing ONLY conductivity and
temperature measurements to be made.
3. To charge the internal batteries, (a) con-
nect the circular plug from the AC bat-
tery charger to the Mark 22 and (b) con-
nect the battery charger to an 120 V / 60
Hz AC power outlet.
CAUTION: Make sure the power
switch is OFF when connecting or
disconnecting the battery charger.
The power switch can be on or off
when charging the internal batteries.
4. After all sensor and power connections
have been made, the Mark 22 can be op-
erated. Flip the switch labeled POWER
to the UP position ( power on ). Flip the
switch labeled LAMP to the UP ( back-
light on ) to illuminate the Mark 22’s dis-
play. The Back Lighting Lamp in the Mark
22 display consumes considerable power,
and as a result will limit the unit's bat-
tery powered operating time to approxi-
mately FOUR hours. With the Lamp OFF,
the Mark 22 will provide reliable opera-
tion for approximately 12 hours or more.
5. The Mark 22 sequentially displays date,
time and battery voltage; corrected con-
ductivity, raw conductivity and tempera-
ture; and solution compensated pH, pH
and temperature. Depress the
SELECT
key and observe that the letter "M" ap-
pears in the lower right corner of the
Mark 22 display. The "M" indicates that
Manual Mode is in operation. The Mark
22 will then continuously display the cur-
rently displayed parameter. Depress the
SELECT
key again, and the displayed
data advances to the next set of param-
eters .
Depress the
EXIT
key to exit the Manual
Mode. Observe that the letter "A" appears
in the lower right corner of the units dis-
play. The letter "A" indicates that the
Manual Mode has been exited and that
the unit is now in the Auto Mode of op-
eration. When in the Auto Mode the Mark
22 will continuously scan through all of
its measured as well as manually entered
parameters.
6. The
FOUR MODE KEYS
along the bot-
tom row of the front panel (SETUP, CELL,
LOG, and PRINT) refer to the different
modes of operation featured by the Mark
22. The four tri-legened FUNCTION keys
along the top row of the front panel are
used differently during each mode. To fa-
cilitate operation of the Mark 22 the func-
