How do you calibrate an ORP probe?

[orthokardia]

My uncalibrated ORP probe is reading 425 which is up from 315 over about 3 weeks. I have cal solution, but what i have read leads me to believe cal is sketch. BTW the probe is 1month old, in the sump, i do NOT run ozone "yet", and i control with APEX.

thx,
-bart

 

[ToXIc]

taken from pinpoints ORP monitor pdf

•Calibration
The PINPOINT REDOX/ORP Electrode is widely considered to be a
superior grade and should be precisely calibrated to the PINPOINT
ORP/REDOX Meter before use. Place the tip of the red electrode into the
REDOX 400 Calibration Fluid and wait a minute or so for the
measurement to settle in. Adjust the calibration screw on the front of the
monitor to read 400mV. Calibration should be checked frequently for
maximum precision. Do not reuse the calibration fluid. PINPOINT REDOX
400 Calibration Fluid also performs a thorough chemical cleaning of the
platinum tip and the reference junctions during the calibration process.

for the apex you should be able to do the same.. just via the web GUI instead of a screw..