21
F.
How to Verify Sensor Module Calibrations
Verify that the measurement sensor module is properly calibrated before use or whenever
inaccurate readings are suspected. When required, always use reference standards that
are traceable to the National Institute of Standards and Technology (N.I.S.T.) and that
have not expired or are past the open bottle time.
1.
90XL Conductivity/Temperature Sensor Module
a)
90XL Conductivity
CAUTION:
Use only sodium chloride (NaCl) standard solution. The
conductivity/temperature sensor module is temperature-compensated for NaCl
solution. Other solutions, such as potassium chloride (KCl), may result in
inaccurate calibration.
Gather the following supplies:
·
14.0 mS conductivity standard solution (NaCl) Mesa P/N 02.0027
·
90XL Sample Kit Mesa P/N 503110017
To verify calibration of the conductivity/temperature sensor module:
1.
To rinse the sample tray and sensor module, pour approximately 50 ml of
fresh reference solution into the sample tray. Insert the conductivity sensor
module into the center sensor holder of the tray.
2.
Insert the syringe assembly to the top male Hansen fitting of the sensor
module. Draw rinse solution through the sensor module, and expel through
the sensor module.
3.
Discard the rinse solution – do not pour used solution back into the original
container.
4.
Pour approximately 50 ml of fresh solution into the rinsed sample tray. Make
sure the conductivity sensor module is inserted into the center sensor
holder.
5.
Draw standard solution slowly through the sensor module and observe the
reading on the display. If the value on the display reads within specified
limits based on the standard solution value used, then calibration is not
needed. If this displayed value falls outside of specified limits, then
calibration is required. See the section entitled “Calibration and
Maintenance”.
14.0 mS conductivity
standard solution
Center sensor holder