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Chapter 5 | Measurements
Chapter 5
Measurements
5.1 Read Types
The
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.
At any time during the measurement, press the “Hold” key
to lock the measurement on the display (Hold icon will be
shown on the display) and then press the Hold key a
second time to release the hold and view live
measurements again.
5.1.2 Auto-Read
In the Auto-Read measure mode, press the “Read” 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 “Read” 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.
5.2 Conductivity, Salinity
and TDS Measurements
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 measurement plates and temperature sensor.
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.
5.3 Calculating TDS Factor
To determine the conductivity-to-TDS conversion factor,
the following formula can be used:
Factor = Actual TDS ÷ Actual Conductivity @ 25ºC
•
Actual TDS: Value from the solution bottle label or
as a standard made using high purity water and
precisely weighed salts.
ppm = milligram of salt per liter of water = mg/L
ppt = gram of salt(s) per liter of water = g/L
•
Actual Conductivity: Value measured using a
properly calibrated Conductivity/Temperature
meter.
Both the Actual TDS and the Actual Conductivity values
must be in the same magnitude of units. For example, if
the TDS value is in ppm the conductivity value must be in
µS; if the TDS value is in ppt the conductivity value must be
in mS.
Check the factor by multiplying the conductivity reading by
the factor in the above formula. The result should be in
TDS value.
When the TDS factor is set to 1.0, Conductivity = TDS.
Summary of Contents for Fisherbrand accumet AB330
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