142
DO Operation:
BOD Measurement
XL40 and 60 meters
The measurement mode is used to measure Dissolved Oxygen (DO) in %Sat, mg/L or mbar. The
DO measure screen provides a readout from the DO probe attached to the meter. Before
measuring DO, you will need to standardize your probe: see
‘
DO Operation: Standardizing’
section
for details. It is good practice to standardize the probe daily for best results.
If the Auto Read is active, the meter will lock (freeze) onto a reading when it is stable. The meter
will not change from this reading until the Measure button is pushed, at which time a new reading
is taken. If the Auto Read is not active, the meter will continuously monitor the DO and the
reading will indicate any change in the DO level. If the
STABLE
indicator is turned on, the
STABLE
indicator appears on the screen when the reading meets the chosen stability criteria.
NOTE:
Prior to sample measurement, verify the salinity of the sample and enter that salinity value
using the setup menu (see
‘
DO Setup: Set Salinity / Set Alarm Limits’
section
for details).
To Measure DO with Auto Read ON
1. Immerse rinsed DO probe into the
sample solution, constantly stirring
the solution.
2. Touch
Measure.
3. The meter will continuously
measure the sample until the
stability criteria is met. At this time
the reading will freeze and the
STABLE*
indicator appears.
4. Record the reading once the
measurement has become stable.
5. To take another reading, repeat
steps 1 to 4.
* Please note that
STABLE
will only appear if you
have completed a successful two point calibration.
To Measure DO with Auto Read OFF
1. Immerse rinsed DO probe into the
sample solution, constantly stirring
the solution.
2. The meter will continuously
measure the sample until the
stability criteria is met. At this time
the
STABLE
indicator
appears.
3. Record the reading once the measurement has become stable.
4. To take another reading, repeat steps 1 to 3.
NOTES:
You can access other functions of the meter with the remaining buttons on the measure
screen.
• Touching
Setup
will access the Setup screen.
• At anytime, you can touch Mode to access another mode of operation including: BOD, OUR and
SOUR.
Summary of Contents for XL 20
Page 1: ......
Page 138: ...127 Ion Operation Known Addition Method XL25 50 and 60 meters...
Page 140: ...129 Ion Operation Known Subtraction Method XL25 50 and 60 meters...
Page 142: ...131 Ion Operation Analate Addition Method XL25 50 and 60 meters...
Page 144: ...133 Ion Operation Analate Subtraction Method XL25 50 and 60 meters...