Chapter 5; Measurements; Read Types; Continuous - Thermo Scientific Orion Lab Star DO113 Operation Manual

Chapter 5

Measurements

5.1 Read Types

The Read Type selected in the meter Setup Menu will
determine how measurements are performed and when
measurements are saved to the data log and exported to
an external device. Set the Read Type as Continuous,
Auto-Read or Timed to define.

5.1.1 Continuous

In the Continuous measure mode, measurements are
continuously updated on the display and the stopwatch
(stabilizing) or checkmark (stable) icon indicates the
measurement stability status.
Press the "Log/Export" key to save a measurement to the
data log and export.

5.1.2 Auto-Read

In the Auto-Read measure mode, press the "Measure" key
to start a measurement.
When the measurement is stable, the checkmark (stable)
icon is shown and the measurement is locked on the
display until the "Measure" key is pressed again.
The stable measurement is automatically saved to the data
log and exported.

5.1.3 Timed

In the Timed measure mode, the measurement values are
continuously updated on the display.
Measurements are automatically saved to the data log and
exported at the selected time intervals, from 5 seconds to
60 minutes, the entire time the meter is in the
measurement mode.
30 Chapter 5 | Measurements

5.2 DO Measurements

The Orion Lab Star DO113 dissolved oxygen meter
measures dissolved oxygen as percent saturation,
dissolved oxygen as concentration in mg/L and dissolved
oxygen as concentration in ppm.
In the main measure mode, press and hold (long press) the
 or  key for approximately three seconds to change the
main measure mode to dissolved oxygen as % saturation,
concentration in mg/L or concentration in ppm.
Dissolved oxygen levels vary with temperature, barometric
pressure and salinity, so calibration must be performed
with consideration of these factors. It is necessary to set
the proper temperature, barometric pressure and salinity
values prior to performing any DO calibration or
measurement.
Note: Consumption of oxygen by the DO electrode can
cause a lowering of the oxygen concentration at the
boundary layer between the sample and the electrode
membrane. For this reason, sample stirring is required.
Rinse the electrode with distilled water or
appropriate solution and blot gently with a lint-free
tissue to remove excess water.
Place the electrode into the sample, submerging the
membrane and temperature sensor. Ensure the
sample is being stirred.
Allow time for the reading to stabilize.
The meter displays the stopwatch icon while the
reading is stabilizing.
The meter displays the checkmark icon when the
reading is stable.
Note the displayed measurements as required.
Remove the electrode from the sample.
Repeat steps 1-5 for all samples.
When all samples have been measured, store the
electrode per instructions in the electrode manual.