EUTECH INSTRUMENTS ?lpha-pH500, Manual, Page: 26 / 32

8 T R O U B L E S HO O T I NG G UI D E
Problem Cause Solution
Power on but no
display a). Loose connections
b). Cables not in correct
polarity (+ and – position).
a). Check cables are making good
contact.
b). Re-wire loop cables with
correct polarity.
Unstable readings a). Air bubbles in probe.
b). Dirty probe.
c). Probe not deep enough in
sample.
d). External noise pickup or
induction caused by nearby
electric motor.
e). Severe Reference junction
fouling.
a). Tap probe to remove bubbles.
b). Clean the probe and re-
calibrate.
c). Make sure sample entirely
covers the probe sensors.
d). Switch to Symmetrical mode
and connect PMP.
e). Replace probe.
Slow response a). Dirty / Oily probe. a). Clean probe. See “Probe Care
& Maintenance”, Section 7.