OPERATION MANUAL
5
4. Maintenance and note
Notes for Testing Sample
z
The electrode plug and socket of instrument must keep clean and dry, short circuit
plug should be put on when not using, for preventing the intrusion of dust and
moisture.
z
The different sample should use the suitable pH electrode(for example: measure
strong acid
、
strong alkali or pure water and so on.
z
The lead-in wire of electrode must keep static when test the sample, don't touch it
with hand, otherwise it will cause the measurement instability.
z
The preparation standard solution must use the twice distilled water or Non-Ion water,
its conductivity should be less than 2
μ
s/cm.
z
The standard buffer solution should be stored in the refrigerator (low temperature
around 5-1
0℃
), it can preserve for 2-3 months. If there is muddy, mildew or sediment
in the solution, please do not use any more.
z
Don't use the standard buffer solution which passed the shelf life, don't pour the used
standard buffer solution into the standard solution bottle with unused solution.
z
Use the standard buffer solution which approach the pH value of sample if possible
when in calibration, and the standard solution temperature is better the same with
sample if possible.
z
It would be best to turn off and calibrate again if need to replace the electrode when
use the instrument.
Notes for electrode use
z
Combination electrode is not supposed to immersed into distilled water for a long
time, it should be inserted into the bottle which is filled with the electrode protect
solution
z
The configuration of electrode protect solution: take one pocket of pH4.00(250ml),
soluble in the 250ml ion water, then add 56g analytically pure KCL, stir until
completely dissolved.
z
Avoiding to let the top of electrode being knocked after remove the protect cover of
