INE-PHS-3E 2016
10
5 MAINTENANCE
The meter should be often maintained, pH meter must have very high input impedance.
There are often chemical reagents in ambient surrounds, so necessary maintenance can
guarantee the meter's normal working.
1) The input end of the meter (electrode socket 6) must be kept dry and clean. When the
meter is not working, please insert Q9 short circuit plug into the socket to prevent from
dirt and water
steam.
2) Electrode transducer (purchased part) is fitted with other electrodes, please keep it
waterproof and dirt proof.
3) While measuring, leading line of the electrode should be kept motionless so as to
avoid unstable measurement.
4) Power supply of the meter must have good grounding.
5) The meter is designed with MOS integrated circuit, therefore the electric welding
machine must have good grounding when servicing.
6)
When calibrating with buffer solution, stability of buffer solution should be assured,
don't make buffer solution by mistake, otherwise it will lead incorrect measuring
results.
6 CAUTIONS FOR ELECTRODE OPERATION
1) Before measuring, the electrode must be made positioning calibration with buffer
solution of known pH value, it would be better if the value is close to measured value.
2) After taking off electrode sleeve, the users must take care of the electrode, glass bulb
must not be touched to hard substance, any damage will make the electrode cease to
be effective.
3) After measurement, put on the electrode sleeve that has little supplementary liquid in it
to keep bulb wet, but don't immerge it in distilled water.
4) Out reference supplementary liquid of the combination electrode is 3mol/L KCl solution,
it can be added from the small hole on the top or electrode. When combination
electrode is not working, put on rubber sleeve to prevent supplementary liquid from
dry.
5) The output ends of the electrode must be kept clean and dry to prevent from two ends
short circuit, otherwise measurement will not be correct and effective.
6) The electrode should be fitted with pH meter of high input impedance (
10
12
ȍ
) to keep
good performance.
7) Don't immerge electrode in distilled water, protein solution or acid fluoride solution for
a long time.
8) Electrode can't be touched to organic silica oil.
9) After electrode is used for over a long period of time, if slope becomes lower, immerge
the bottom part of the electrode in 4% HF solution for 3~5 seconds, wash it with
distilled water, then immerge it in 0.1mol/L of hydrochloric acid solution to renew it.
10) If the electrode is inactivated because of the substance that pollutes sensitive bulb in
measured solution, slope will be lower, the value will not be correct. If this happens,
please clean the electrode with some solutions according to the property of polluting
substance. The electrode is then renewed.
