Manual

• Ifthe pHreading isbetween8.0pHand6.0pH,calibratingthe

sensor (see pH Calibration, pg. 20) will correct the offset.

7. Press to return the instrument to measurement mode

without changing the calibration of the instrument.

3. pH/ORP

CAUTION: ONLY authorized members of your facility’s maintenance

staff should attempt the following procedures.

TheuniquepH/ORPsensorinyourDialysateMeterisanonrellable

combination type that features a porous liquid junction.

It should not be

allowed to dry out.

However, if this occurs, the sensor may sometimes

berejuvenatedbyrstcleaningthesensorwellwithisopropylalcohol

or a liquid spray cleaner, such as Windex™ or Fantastic™, and rinsing

well. Do not scrub or wipe the pH/ORP sensor.

Then use one of the following methods:

1. Pour a HOT salt solution ~60°C/140°F — preferably potassium

chloride (KCI) solution (Myron L pH/ORP Sensor Storage

Solution) but HOT tap water with table salt (NaCl) will work

 ne—inthepH/ORPsensorwellandallowtocool.Retest.

2. Pour DI water in the pH/ORP sensor well and allow to stand for

no more than 4 hours (longer can deplete the reference

solution and damage the glass bulb). Retest.

If neither method is successful, the sensor must be replaced.

DriftingcanbecausedbyalmonthepHsensorbulband/or

reference (see Figure 31). Use isopropyl alcohol or spray a liquid

cleaner such as Windex™ or Fantastic™ into the sensor well to clean

it. The sensor bulb is very thin and delicate. Do not scrub or wipe the

pH/ORP sensor.

pH/ORP SENSOR

Top View

ORP

Electrode

pH Glass

Electrode

Sensor

Body

Reference

Junction

under Glass

pH Bulb

Figure 31