Manual

YSI Incorporated 6500 Field Guide 4
FIELD CALIBRATION
Below are instructions for calibrating the sonde sensors using the
6500 monitor. If the monitor is mounted outside and the air tem-
perature is below freezing, take care not to expose the sensors for
prolonged periods during calibration. Below is a list of supplies
you will need to take to the deployment site. Also, you need to
know the local barometric pressure for DO calibration.
!
Bucket of clean water to rinse sonde body between cals.
!
Small brush for cleaning the conductivity cell ports.
!
Calibration/storage vessels provided with the sonde.
!
Standards for pH (pH 7 and one other buffer for 2-point cal).
!
Conductivity standard (KCl, usually 10 mS/cm at 25
o
C).
!
Latex gloves, towels, pre-rinse solutions, and lab notebook.
Conductivity Calibration
Before you proceed make sure that you have a clean, dry sonde and
about 320mls of standard in the cali-
bration cup. It is critical that the con-
ductivity vent hole be completely
submersed and that the reading is
stable before confirming the calibra-
tion value.
With the sonde submersed in standard
as described above, press
Enter
to
display the
Specific conductance
screen. Using all 4 arrow keys
(left/right for digit, up/down to change value), enter the appropriate
cal value, then press
Enter
.
A live display of specific conductance
appears. With the highlight on
Cal
,
press
Enter
to confirm the calibration.
A message will appear confirming the calibration and displaying
the new value (e.g., 10.00 mS/cm).
If you choose to abort or redo calibra-
tion for any reason, highlight the ap-
propriate choice above, press
Enter
and continue.
Remove the sonde from the standard. Rinse with water, shake ex-
cess water from sonde body and dry. Continue to the next standard
by pressing
Esc
to return to the
Calibration menu
.
pH Calibration
Before you proceed make sure that you have a clean, dry sonde and
about 200mls of standard in the calibration cup. Pre-rinse in used
standard if possible. It is critical that the pH and temperature
probes be completely submersed and that the reading is stable be-
fore confirming the calibration value.
If performing a 2 or 3-point calibration, always start with pH 7. The
more commonly used 2-point calibration is described below.
From the Calibration menu highlight pH then press
Enter
. High-
light the 2-point option as shown in the screen below, then press
Enter
to view the first cal point, pH 7 in this example.
With the sonde submersed in standard as described above, press
Enter
to display the pH screen. Using all four arrow keys (left/right
for digit, up/down for value), enter the appropriate cal value, then
press
Enter
.