Hach-Lange MTC10130 - Manual (Page 13)

Message or symptom Possible cause Action
Slow stabilization time Contaminated platinum sensor Clean the probe (refer to Clean the probe
on page 11).
Probe not conditioned/pre-treated for
reducing type samples To significantly reduce the response time for reducing
type samples the platinum disc must undergo the
following:
1. Make sure that the platinum disc is clean and
smooth.
2. Put the platinum disc in Reducing Solution for
ORP Electrodes for 3-10 minutes before sample
analysis.
3. Rinse the probe with sample, then measure.
Low sample temperature or temperature
difference between samples Check the sample temperature. The lower the
temperature or the greater the difference of
temperatures between samples, the longer the
response time.
Platinum electrode not conditioned for
reducing-type samples
1. Make sure that the platinum disc is clean and
smooth.
2. Put the platinum disc in Reducing Solution for
ORP Electrodes for 3-10 minutes before sample
analysis.
3. Rinse the probe with sample, then measure.
Air bubbles around inner reference
electrode Gently tap the probe with hand or shake the probe
while holding the probe downward in the
solution/sample to remove any air bubbles in the
reference junction holes.
Out of range Measure value is outside the
calibration/measurement range of the
probe Calibrate again using freshly prepared standards.
Clean the probe and calibrate again.
Make sure that the sample is within the range of the
probe.
Air bubbles around inner reference
electrode Gently tap the probe with hand or shake the probe
while holding the probe downward in the
solution/sample to remove any air bubbles in the
reference junction holes.
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