9
CAL
iB
rA
TiON
Probe Cabling Color Code
Marking
Color
Functionality
–
GREEN
0V
B
WHITE
RS485 D –
A
YELLOW
RS485 D+
+
BROWN
5V
GREEN / YELLOW
PROTECTIVE GROUND CONNECTION
9. CALIBRATION
HI510
Controller allows two types of DO calibration procedures:
• Standard calibration − a two-point calibration with standards
• Process calibration − available only if the probe has been calibrated in
standards previously
Standard Calibration
Preparation
A two point calibration with standards verifies the probe is working correctly and
establishes a slope.
• Verify the probe is filled with electrolyte and is connected to the controller.
• Verify the controller’s barometric pressure reading with a reference meter. The
pressure value can be adjusted from the controller’s Technical Menu.
• Set the Salinity value if probe will be exposed to ocean or brackish waters.
• Set controller to desired measurement unit. Go to Probe Setting in Channel
Setup. Choose between DO_Sat (% saturation) or DO_Conc (Concentration).
Procedure
A two point calibration uses air and zero oxygen solution to calibrate.
1. Press MENU direct key ( ) then
CAL
virtual key. The controller recognizes
the currently selected measuring unit.
2. Suspend the probe into the water-saturated air and wait for the probe to
reach thermal equilibrium.
3. Press
CFM
when displayed followed by
Next.
4. Submerge the probe into
HI7040
Zero oxygen solution and stir gently for
2-3 minutes. Wait for the temperature and probe values to become stable.
The meter will automatically recognize the 0% (ppm) standard.
5. Press
CFM
to confirm the second calibration point and save the calibration.
Process Calibration
A process calibration is a single point calibration performed with the probe
installed in the process. This type of calibration allows the user to adjust the
measured DO value so that it matches the value determined with the hand-held
meter. Prior to performing a process calibration, a hand-held meter and probe
must be used to determine the DO value of the process.
Preparation
• Determine the process DO value, using a calibrated portable meter and probe.
• The process controller and the probe should have previously been calibrated
with two standards (so a probe slope has been determined).
Procedure
1. Press MENU direct key ( ) then
CAL
virtual key.
2. Press
Process
when it is displayed.
3. Adjust the process value in agreement with the predetermined value using the
directional keys (
). Press
CFM
to confirm and save the calibration.
10. MAINTENANCE
DO Probe & Cap Membrane Cleaning
• Inspect, clean, and calibrate the probe at regular intervals. Alternatively, follow
Standard Operating Procedures (SOP) guidelines.
• Rinse the probe, with cap assembled, with clean water. Blot the probe with a
soft cloth or tissue. Handle the probe and membrane carefully to avoid damage.
