27
CALIBRATION - 5
Martek Instruments, Inc.
solution. When the voltage displayed has sta-
bilized, press the
SELECT
key. The Mark 22
will prompt with the following display:
Input the temperature value as a 4-digit
number (note the fixed decimal point). You
can edit the value of the flashing digit by
pressing the UP or DOWN ARROW keys.
Move forward to the next digit by pushing
the
SELECT
key. Move back to a previous
digit by pushing the
EXIT
key. After the last
number has been entered, the Mark 22 will
automatically respond with the following
d i s p l a y :
and the "COND" prompt will be flashing. At
this point, press the
EXIT
key twice to re-
turn to the Display Monitoring Mode.
5.2
C
ONDUCTIVITY
C
ALIBRATION
5.2.1
Conductivity Zero Adjustment
After the temperature has been calibrated,
connect a dry the Martek Conductivity Ref-
erence Cell or any other dry reference cell to
the Mark 22 (See Section 3.2.1 for instructions
on how to connect sensors to the Mark 22).
[An alternate method is to use the conduc-
tivity interconnect cable (P/N 603051) to
simulate a conductivity reference cell. To use
this cable, connect it to the Mark 22 and in-
sert the Martek Zero Calibration Plug (P/N
400550). [ Select the cell constant you will be
measuring with (i.e. 0.0100, 0.1000, 1.000, or
10.00), and proceed with the zero calibration.]
Next, press the
CELL
key to locate the
correct
cell constant
or
"K" factor
that should
be used with that particular conductivity sen-
sor. The "K" factor is listed for reference on
the Martek Reference Cell's cable. If the "K"
factor listed on the conductivity sensor is not
present in the Mark 22, review Section 4.2.2
on how to change cell constants. If using the
calibration plug, select the " K " factor near-
est the reference (i.e. 0.0100, 0.1000, 1.000, or
10.00) from the table in section 4.2.2. Once
the "K" factor has been entered, depress the
CELL key to return to the Display Monitor-
ing Mode.
With the Mark 22 in the Display
Monitorig Mode, depress the
READ
key to
place the unit in Manual Monitoring Mode
until the display indicates conductivity mea-
surements. Next, place the monitor in the
highest conductivity range by pressing the
UP ARROW
key until the decimal point is
furthest to the right as possible. Calibration
in this range minimizes the zero offset.
Return to the calibration mode by press-
ing the
SETUP
key then select the "CAL"
option from the Setup Option Menu. The
Mark 22 display will respond with the fol-
l o w i n g :
Use the UP/DOWN ARROW Keys to get
the COND prompt blinking. Depress the
SE-
LECT
key to choose "COND". The display
will then prompt:
INP 4 DIGIT STD.
HI TEMP = 50.00
TEMP
COND
pH
TIME
ZERO SPAN
CONDUCTIVITY
TEMP
COND
pH
TIME
