wtw Multi 3620 IDS - Page 106

Multi 3620 IDS What to do if...
ba77169e01 04/2016 106
Error message,
Error
No stable measured
value
– Air in the junction – Extract air or moisten junction
– Gel electrolyte dried out – Exchange IDS-pH sensor
Cause Remedy
Cause Remedy
IDS-pH sensor:
– The values determined for zero
point and slope of the IDS-pH
sensor are outside the allowed
limits.
–Recalibrate
– Junction contaminated – Clean the junction
– IDS-pH sensor broken – Exchange IDS-pH sensor
Buffer solutions:
– The used buffer solutions do not
agree with the set buffer set
– Set different buffer set
or
– Use different buffer solutions
– Buffer solutions too old – Use only once.
Note the shelf life
– Buffer solutions depleted – Change solutions
Cause Remedy
IDS-pH sensor:
– Junction contaminated – Clean the junction
– Membrane contaminated – Clean membrane
Test sample:
– pH value not stable – Measure with air excluded if neces-
sary
– Temperature not stable – Adjust temperature if necessary
IDS-pH sensor + test sample:
– Conductivity too low – Use suitable IDS-pH sensor
– Temperature too high – Use suitable IDS-pH sensor
– Organic liquids – Use suitable IDS-pH sensor