User Guide

pH/ORP PROBE CHECK

The pH electrode and the reference electrode for both pH

and ORP can be automatically monitored through HI

504910.

Setup items involved are I.13 (pH electrode impedance test

enable), I.14 (reference electrode impedance test enable) and

I.15 (maximum reference electrode impedance).

A “pH electrode broken or leakage error” (error code: 10) is

generated whenever the pH electrode impedance is less than

1 MΩ. This error can be due to breakage of the electrode

glass or short circuits caused by moisture or dirt.

A “reference electrode broken or dirty or not immersed” error

(error code: 11) is generated whenever the reference elec-

trode impedance is greater than the value set in item I.15

(maximum reference electrode impedance range is 0.5 to

100.0 KΩ, default is 50.0 KΩ). This error can be due to

soiling of the reference electrode. It can occur also when the

reference electrode or the matching pin are not immersed in

the solution.

The pH electrode test is performed when the following condi-

tions are satisfied:

• the test has been enabled through the setup item I.13;

• the device is in one of the following modes: measure, last

calibration data scrolling, event log file scrolling;

• the device is configured to measure pH.

Note If an amplified electrode is used, the pH electrode test

must be disabled by the user through the setup item

I.13.

The reference electrode test is performed when the following

conditions are satisfied:

• the test has been enabled through the setup item I.14;

• the device is in one of the following modes: measure, last

calibration data scrolling, event log file scrolling.

Note When testing or calibrating the instrument through a

pH/ORP simulator like HI 931001 or HI 8427, tempo-

rarily set the item I.13 to “OFF” and short the Match-

ing pin and the Reference pin terminals.