H87.0.0X.6C-01
Operating manual G 7500 Series
page 19 of 34
6.6.5 Measurement accuracy
The measurement accuracy can be impaired by:
▪ An inadequate flow below the necessary value of approx. 30cm/sec.
▪ The water temperature and sensor temperature must be the same. The most
accurate measurements are provided when the measuring temperature is
calibrated.
6.6.6
Visible residues inside the membrane cap
As a reaction product, lead oxides (brown or red, from reaction with oxygen) and lead
carbonate (white, from reaction with carbon dioxide) are created during operation on
the lead anode. These substances can collect on the membrane, but they do not
usually affect the measurement function. Most of these substances can be removed
during the maintenance of the sensor.
Prior to screwing on the membrane cap, they should be removed as far as possible in
order to prevent particles from being trapped between the membrane and the
platinum cup. A rapid or excessive formation of lead carbonate after commissioning is
an indication of air in the sensor. This is usually due to incomplete filling or a leak due
to improper fitting of the cap / fill screw or membrane leak.
6.7 Commissioning / filling of the sensor GWO 5610
The electrode contains potassium hydroxide. This causes burns. All
contact with the skin, clothing and eyes should be avoided.
Nevertheless, should contact occur, take the following measures.
a) Eyes: Flush with flowing water for at least 15 minutes, seek medical
attention!
b) Skin: Wash with large amounts of water for several minutes!
c) Clothing: Remove immediately!
d) If swallowed: Drink large amounts of water, do not induce vomiting
and seek medical attention!
Protective goggles must be worn for all of the following activities!
Protective gloves must be worn for all of the following activities!
The sensor is delivered dry. Therefore, the sensor is well-suited for storage. The
sensor must be filled in good time before the measurement. A wait time of approx. 2
hours after filling should be planned in order to allow the sensor to stabilize.
