222 mV (25˚C) ORP Standard Buffer Solution Calibration Reference Table
Temperature (˚C)
mV
Temperature (˚C)
mV
10
242
30
215
15
235
35
209
20
227
38
205
25
222
40
201
For example, if the temperature is around 25˚C, then adjust the calibration value to 222 mV. If the
temperature is around 20˚C, then adjust the calibration value to 227 mV.
press
to complete the calibration.
6.
ORP Measurement
Press
to power on, clean the probe in distilled water and dry it. And place the probe in the
tested solution and stir gently and let it stand still. Read the measurement after comes up and
stays.
7.
Notes
1)
Usually there’s no need to calibrate for ORP testing. When used for a long time, users can
test it in 222 mV ORP standard buffer. If the error is big, please calibrate according to the
steps in 5.1 to 5.4.
2) The meter has self-diagnosis function. Please refer to the followed chart for detailed
information.
Symbol
Self-Diagnosis information
How to fix
is pressed before the
measurement becomes stable
(smiley face comes up)
Wait till the smile icon appears and
stays, then short press
7.1
The cleaning and activation of ORP probes
After long-time use, the surface of the platinum sensor can be contaminated and cause
inaccuracy and slow response time. If that happened, the followed methods can be adopted to
clean and activate:
a) For contamination caused by inorganic substances, dip the probe into 0.1 mol/L dilute
hydrochloric acid for 30 minutes. Clean it with distilled water, soak it into the KCL
storage solution for 6 hours, and then it will be ready for use again.
b) For contamination caused by organic substances and oiliness, clean the platinum
surface with dishwashing liquid, and wash with distilled water. And then the probe will be
ready for use again after 6 hours’ soaking in the storage solution.
c) If the platinum surface is so severely contaminated that there forms an oxide film,
toothpaste can be used to clean the platinum surface, and then wash it with distilled
water. The probe will be ready for use again after 6 hours’ soaking in the storage
solution.
