Troubleshooting; Ph System Messages - wtw pH 330/SET Bedienungsanleitung

pH 330
pH 340

pH system messages

System message
 /
Indication range
exceeded

Slope or asymmetry
outside of
admissible ranges
(Slope:
-50 ... -62 mV/pH;
Asymmetry:
-30 ... +30 mV)
50
Cause
pH electrode:
• Not immersed
• Cable broken
• Electrolytic gel dried
• Air bubble in front of
diaphragm
• Air in diaphragm
pH electrode:
• pH electrode too old
• Diaphragm contaminated
• Membrane contaminated
• Moisture in the plug
• Electrolytic gel too old
Meter:
• Wrong calibration procedure
• Wrong temperature of
(
solution Without
temperature probe only)
• Moisture in the socket
Buffer solution:
• Unsuitable buffer solutions
• Buffer solutions too old
• Used up buffer solutions

Troubleshooting

Action
pH electrode:
Immerse into sample solution
Exchange electrode
Exchange electrode
Remove air bubble
Suck off air or moisten
diaphragm
pH electrode:
Exchange pH electrode
Clean diaphragm
Clean membrane
Dry plug
Exchange electrode
Meter:
Select correct procedure
Set correct temperature
Dry socket
Buffer solution:
Use WTW Technical buffer
solutions
Pay attention to perishability of
solutions.
Use solutions only once.