6
•
Due to shipping or storage the internal solution inside
the PVC modules may have developed an air pocket
near the membrane. Gently shaking the sensor down
(like the old style mercury thermometer) will place the
internal solution next to the membrane.
•
Presoaking the Calcium sensor in HI 4004-45
solution for at least half-hour before calibration will
help to optimize the sensor response.
•
Do not leave your sensors in standard or samples
with ISA for long periods of time.
•
Calibration standards and sample solutions should
have the same ionic strength. ISA should be added to
both samples and standards.
•
Calibration standards and sample solutions should
be at same temperature.
•
Thermally insulate solution vessel from magnetic stir-
rer.
•
Calibration standards and sample solutions should
be stirred at the same rate using identical sized TFE
coated stir bars.
•
Rinse electrodes with distilled or deionized water be-
tween samples and gently dab dry with lab wipe or
other soft disposable absorbent toweling. Do not rub
the sensing surface.
•
Check for gas bubbles that may form near sensing
surface (due to solution temperature changes). Tap
off gently.
•
Avoid large changes in temperature (thermal shock)
as it may damage the sensor.
Note: The electrode membrane will develop a opaque
appearance when it becomes wetted. This is normal.
