Instructional manual- HBPH-MK2
– UK-004
Page 8
Issue:
Likely cause:
Troubleshooting:
The output of the sensor DOES
change between pH buffers but not
as good (quick) as it should (or did)
before.
Span less than 0.9mA/pH
The process electrode (glass bulb) is
coated with scaling or biofouling
A coated electrode will create a
narrower span
If the coating is from scaling then soaking the
probe in a weak acid (e.g. vinegar or 0.1M
HCl) will remove the scale. If the coating is
from fouling then soaking the probe in
bleach will clear it.
The offset is outside of spec:
11mA > pH7 > 13mA
The reference solution has been
contaminated with the process or
the salt bridge has fouled
Salt bridge replacement is needed
The pH reading DOES NOT change
at all when changing from one
calibration solution to another
The process electrode is inoperable
(likely cracked or broken) or the
printed circuit board (PCB) has
failed
Sensor is non-repairable
The output is outside of 4-20mA
The sensor electronic has failed
Sensor is non-repairable
Parts and Accessories
Description
Part #
3-pack salt bridge replacement kit
HBPH-SB-KIT
Controller for pH Sensor
HBPH-C1
Controller for pH Sensor
HBPH-C1-ENC
Sensor Return
If you are returning a probe for inspection, enclose description of the problem. Pack the probe adequately
to avoid damage to the glass electrode and ensure that it will not be exposed to temperatures below -15°C.
HB Products cannot be responsible for shipping damage or for damage due to frozen electrodes. For safety
reasons, HB Products cannot accept probes which have not been thoroughly cleaned to remove all process
material and put a piece of cotton ball with a few drops of water into the protective cap and place it on the
sensor with tape to prevent it from drying out.
Further Information
For further information, please visit our website,
, or send an email to:
HB Products A/S
–
Bøgekildevej 21
–
DK8361 Hasselager
–
–
www.hbproducts.dk