In-Situ Aqua TROLL 100 and 200 Operators Manual - Manual (Page 49)

Page 49 Aqua TROLL Operator’s Manual
Section 5: Conductivity
range of approximately 100 to 60,000 microSiemens/cm (µS/
cm).
When carbon dioxide from the air dissolves into water it
increases the conductivity, sometimes by as much as one or two
µS/cm. This could shift a 146.9 standard by as much as 3%. The
amount of shift is not predictable, so it should be minimized by
limiting exposure to air. Fill the calibration cup to the marked
fill line and close it as soon as possible. A small air bubble in
the cup is acceptable, and in fact it assists mixing during the
inversions. Discard remaining portions of low range calibration
standards within a few days after opening the bottle.
To perform a conductivity calibration of the Aqua TROLL
Instrument you will need:
4 The In-Situ Cal Cup supplied with your instrument.
4
The calibration standard solution supplied, or other solution
of known specific conductivity in the range 100 to 60,000
µS/cm.
Preparing to Calibrate
Three factors are essential to a successful conductivity
calibration:
A The calibration solution is not diluted or contaminated.
B The probe and the solution are at the same temperature.
C The sensing cell is completely filled with solution—no air
bubbles on the sensor.
The following preparation steps can help to ensure a successful
calibration and avoid erroneous field data.