VWR pH SJ 113 Instrucciones página 2

EN
English
Supply
All electrodes are supplied tested and ready for use, and meet the following characteristic data at time
of delivery.
Electrode slope at 25 deg C
Offset voltage at the zero point pH 7 (25 deg C)
Storage
Unless advised to the contrary, electrodes should be stored in the protective cap or the storage
container with their membranes immersed in VWR KCl storage solution (83605.180). Storage tempe-
rature should be between 10 deg and 30 deg C, but not below -5 deg C. Should any KCl solution leak
from the protective cap during storage or transit (usually seen as a white salt), then it may be easily
removed by rinsing the electrode in water. The electrode will not be affected by this leakage.
Calibration
Carefully rinse electrodes with deionized/distilled water and remove air bubbles by shaking (as with a
mercury clinical thermometer) before immersing up to the diaphragm into the buffer solution.
Always rinse the electrode in deionized/distilled water before using other buffer solutions.
Discard the buffer solution after use. Please note that buffer solutions do have a finite shelf life.
If possible calibration buffer solutions should be at the normal working temperature.
Calibrate electrodes in accordance with the instrument´s working manual.
Where possible, electrodes should be installed vertically or within 30 degrees to the vertical.
Ageing
All electrodes under go a natural ageing process caused by the exchange reactions of the glass
membrane. This usually results in the electrode having a slow response time, decrease of slope, or
changes of zero point. High temperature or aggressive samples will reduce the lifetime of the electrodes.
Please note that even in storage, electrodes will still be subjected to the ageing process. With refillable
electrodes, always check that there is sufficient 3 mol/l KCl electrolyte. The level of the reference
electrolyte should be several cm higher than the level of the measuring medium.
Gel-filled combination electrodes are nearly maintenance free and need no refilling of electrolyte.
Cleaning
pH and Redox combination electrodes can be cleaned by rinsing in deionized/distilled water, and if
necessary dried with tissue paper. (Check that the tissue paper has not left any fibres on the
membrane).
The Redox electrode´s platinum disc or pin may be cleaned by wiping with tissue paper.
Protein contamination may be removed by soaking for 1 hour in cleaning solution (Pepsin/HCl).
After use in oily or organic solution, the pH electrode should be cleaned by dipping into aceton or ethanol
solution for a short period.
After cleaning the electrode should be rinsed thoroughly in deionized/distilled water before soaking in
3 mol/l KCl. The electrode should always be recalibrated before further use.
Ensure that all electrical terminations and connections are kept clean and dry.
Accessories
Storage tube (ECN: 662-1167)
Storage vessel (ECN: 662-1248)
®
BDH Prolabo Storage solution (83605.180)
®
BDH Prolabo Cleaning solution (83603.180)
2
EN English
Buffer pH 4
Buffer pH 7
Buffer pH10 AVS TITRINORM, 100 ml (32040.185)
> 95 % of the theoretical value
< abs. 20 mV
AVS TITRINORM, 100 ml (32095.184)
AVS TITRINORM, 100 ml (32096.187)
ba75996y01 11/2012