NH 500/2
Cleaning and maintenance
15
5
Cleaning and maintenance
5.7
Cleaning
After cleaning, thoroughly rinse with deionized water and recalibrate if
necessary.
5.8
Exchanging the membrane cap
The membrane cap is a wear part and has to be replaced from time to time,
depending on demand and requirements. A reduced slope, an extended
response time or a restricted measuring range indicate that a replacement is
necessary. The exchange is carried out according to the chapter,
C
OMMISSIONING
.
6
Wear parts and accessories
Note
For further accessories, refer to the WTW catalog or the Internet.
Contamination
Cleaning procedures
Water-soluble
contamination
Immerse in deionized water for 10 minutes
Metal hydroxides
Immerse in 10% citric acid
Wear parts and
maintenance
means
Description
Model
Order no.
Accessory set, comprising:
– 3 membrane caps
– 50 ml NH
3
electrolyte solution
ZBK/NH3/2
180 100
Accessories
Description
Model
Order no.
Connection cable for electrodes with plug-
in connector
AS 7
103 614
Alkaline reagent, 10 mol/l NaOH, bottle
with 250 ml
MZ/NH
3
/CN
150 130
Standard solution, 10 g/l ammonium
(NH
4
Cl) , bottle with 1 l
ES/NH
4
120 240