Instruction manual

Sample Requirements

One of the benefits of the ROSS

™

pH Electrodes is that the filling

solution composition may be changed depending on sample

requirements because of the double junction construction. Do not

use solutions containing silver.

The ROSS pH Electrode Filling Solution, Orion 810007, is 3 M KCl.

For solutions which precipitate in the presence of chloride ion, the

ROSS pH Electrode could be filled with 10% KNO

, Orion 900003.

In organic solutions a minimum of 20% water must be present in

the sample. If there is a great deal of drift in organic solutions when

using the ROSS Electrode filled with ROSS Internal Filling Solution

(Orion 810007), try filling the ROSS Electrode with a mixture of

methanol and water saturated with KCl.

The major advantage of the ROSS Sure-Flow

Electrode is that the

junction can be cleaned at any time by briefly depressing the cap.

See Figure 3. This can be done whenever necessary. To be sure to

maintain a proper level of filling solution, refill as in step 3 of

Electrode Preparation.

Figure 3: ROSS Sure-Flow Electrode Being Flushed