Chapter
6
|
RDO/DO Measurement Module
RDO and DO Mode Menu
Main Menu
Settings
Details
Electrode SI No
----
Use the alphanumeric keypad
to enter the serial
number or clear all to shown no value (----)
Sample ID
Off, Manual, Auto Increment
Use the popup keypad screen to enter an
alphanumeric manual ID or a numeric value as
the starting value
for auto incremental ID
Measurement Unit
mg/L,
%
Set the displayed measurement units
Resolution
0.1,
0.01
1,
0.1
Set the resolution of the measurement value
Stability
Smart, Fast, Medium, Slow
Set when a measurement is recognized as stable
Averaging
Off,
Automatic Smart
Set averaging for faster measurement stability
Read Type
Auto-Read, Timed,
Single-Shot, Continuous
For Timed and Single-Shot, set the time in hours,
minutes, seconds using
the arrow keys
Pressure Comp
Auto, Manual
775.0
Set the barometric pressure compensation
source as Auto to use the built-in barometer or
Manual to enter a value. Select the
Auto option
to calibrate the barometer pressure reading
Salinity Correction
Auto, Manual
Set the salinity correction source as Auto to use
a conductivity module
and probe to measure the
sample salinity or Manual to enter a value
Alarm
Limit Alarm
Off, On
Set high and low limit values to activate alarm
Cal Due Alarm
Off, On
Set a calibration interval (hours) to
activate alarm
Set Point Alarm
Off, On
Set a base and offset value to activate alarm
Detailed information on these features is available in the
Appendix
section of this user manual.
RDO Electrode Information
The serial number, remaining cap life and date of manufacture for each RDO optical cap can be
viewed in the RDO Electrode Information menu when the RDO probe is connected
to the meter
and recognized in the measurement mode.
1.
Verify that the RDO probe is connected to the meter.
2.
In the measurement mode, press the
setup key.
3.
Press the
◄ or
► key to highlight Channel # (channel
with the RDO probe) and press the
f3 (Select) key.
4.
Press the ◄ or ► key to highlight RDO Electrode
Information and press the
f3 (Select) key.
66
|
Orion V
ERSA
S
TAR
Meter User Manual
Thermo Scientific
Chapter
6
|
RDO/DO Measurement Module
Dissolved
Oxygen Calibration
Note: A polarographic DO probe must be polarized prior to use. The probe is continuously
polarized when connected to the meter. If the polarographic DO probe is new, has been
serviced or has not been connected to the meter: connect the probe to the meter, power on the
meter and wait 30 minutes for the probe to polarize.
The V
ERSA
S
TAR
meter with RDO/DO module offers the following calibration options:
·
Water Saturated Air – This is the simplest and most accurate method and uses the
calibration sleeve included with most DO probes. For best accuracy, the calibration
temperature should match the expected sample temperature. Moisten the sponge in the
calibration sleeve with distilled water and insert the probe into the sleeve. A BOD bottle can
be used with just enough distilled water to cover the bottom without touching the probe.
·
Air Saturated Water – This method uses water that is 100% saturated with air. Bubble air
into a water sample for an extended period, preferably overnight.
·
Manual (Winkler) – This method uses a water sample with a known concentration of
dissolved oxygen and is typically used to calibrate the DO probe to the value achieved by a
Winkler titration. Due to possible titration errors, this method is inherently less accurate.
·
Set Zero – This method uses an oxygen free solution to add a zero point to an existing
Water Saturated Air or Air Saturated Water calibration. This calibration is generally
recommended when measurements are below 10% saturation or 1 mg/L.
Prepare the DO probe according to the instructions in the probe user manual. Connect the
probe and any other electrodes to be used to the module inputs on the selected channel.
In the measurement mode, press the
channel key until the channel with the RDO/DO module
with DO probe connected is shown.
Water Saturated Air Calibration
1.
Press the
f1 (Cal) key to start the calibration.
a.
If more than one channel is displayed
in the measurement mode, press the
▲ or
▼
key to highlight the desired channel and press the
f3 (Select) key.
2.
Press the
▲ or
▼ key to highlight Water Saturated Air and press the
f3 (Select) key.
3.
Prepare the DO probe and calibration sleeve and allow them to reach equilibrium.
4.
When the DO probe and calibration sleeve are ready, press the
f3 (Start) key.
5.
Wait for the dissolved oxygen value on the meter to stabilize and press the
f2 (Accept) key.
a.
With a polarographic DO probe, 102.3 % will be displayed when the reading stabilizes.
b.
With an RDO optical DO probe, 100.0 % will be displayed when the reading stabilizes.
6.
Press the
f3 (Cal Done) key to save and end the calibration.
7.
The meter will display the calibration summary and export the data to the calibration log.
Press the
measure (esc) key to proceed to the measurement mode.
Thermo Scientific
Orion V
ERSA
S
TAR
Meter User Manual
|
67