Maintenance; Cleaning Of The Cell; Confirming Sensor Abnormality - YOKOGAWA SC4AJ Series User Manual

5.

Maintenance

If the cell becomes fouled, an insulating layer may be formed on the electrodes. As the result, an
apparent increase in cell constant may occur, giving a measuring error. Check and maintain the
sensor in case of an error occurrence.
5.1

Cleaning of the cell

• For lime, hydroxides, etc.
• For organic foul (oil, fats, etc.)
• For algae bacteria or moulds
• For normal applications
WARNING
Do not mix hydrochloric acid with chlorinated solvents (bleach), otherwise toxic chlorine gas may
be generated.
After cleaning, inspect visually to confirm there is no damage or deformation of the cell.
5.2 Confirming sensor abnormality
If there seems any problem on the sensor, fully dry the cell and measure the resistivity between
cable terminals with degital multimeter or the like.
When resistivity is out of the range shown below, sensor is in abnormal status. Replace the
sensor.
Combination of Terminals
Cables (excluding -VS)
11-12
11-13, 13-15, 12-15
13-14, 15-16
* See the pin number of Variopin connector as shown below.
: 5 to 10% solution of hydrochloric acid is recommended.
: they can be removed with ethyl alcohol or acetone.
: use a chlorinated solution (domestic bleach).
: hot water with domestic washing-up liquid will be effective.
Variopin Connector (-VS) *
E-F
E-C, C-A, F-A
C-D, A-B
A
B
H
C
G
D
E F
< 5. Maintenance >
Standard Resistance
(room temperature)
1000 to 1137 Ω
more than 100 MΩ
less than 10 Ω
IM 12D08F03-02E
5-1
10th Edition: Sep. 30, 2019-00