Frequency Of Calibration - Martek MARK 22 Operation Manual

down. Move forward to the next digit by
pushing the SELECT key.
previous digit by pushing the EXIT key. Once
the last digit has been entered, the Mark 22
will automatically respond with the follow-
ing display:
DATE
and the "TIME" option will be flashing. Press
the SELECT key. The display will then indi-
cate the following:
INPUT
TIME
The "hh" stands for the hour and the "mm"
stands for the minutes. The time must be in-
putted as a 24 hour clock, i.e. 1:00 PM would
be inputted as 1300, 9:30 AM would be in-
putted as 0930, etc. Alter the value of the
flashing digit by pressing the arrow keys up
or down. Move forward to the next digit by
pushing the SELECT key.
previous digit by pushing the EXIT key. Once
the last digit has been entered, the Mark 22
will automatically respond with the follow-
ing display:
CAL
CELL
Press the EXIT key to return to the moni-
toring mode.
Martek Instruments, Inc.
Move back to a
TIME
hhmm
0101
Move back to a
COMP
LOG
CALIBRATION - 5
5.6 F
REQUENCY OF
Standard operating procedures for cali-
bration vary with each organization. Martek
Instruments recommends calibration of the
Mark 22 for all parameters at least once a
month. More frequent
required if the displayed values are unusu-
ally high or low, or if the application itself
changes.
In general, pH sensors are unstable elec-
trodes and will require more frequent cali-
bration. Temperature and conductivity are
much more stable and will require less fre-
quent calibration.
C
ALIBRATION
calibration may be
33