Instruction manual

Measuring Hints

See Figure 5.

• Always use fresh buffers for calibration. Choose buffers that

are no more than 3 pH units apart.

• Check electrode slope daily by performing two-buffer

calibration. Slope should be 92 - 102%.

• Except as noted in Sample Requirements, only use ROSS

™

Internal Filling Solution, Orion 810007, for ROSS Combination

pH and Reference Electrodes. Do not use any filling solution

which may contain silver.

• Remove filling hole cover during measurement to ensure

uniform flow of filling solution.

• Between measurements, rinse the electrodes with distilled

water and then with the next solution to be measure.

• Stir all buffers and samples

• Place a piece of insulating material (e.g. styrofoam or

cardboard) between magnetic stirrer and beaker to prevent

error from transfer of heat to sample. Since ROSS Electrodes

respond faster than conventional electrodes, changes in pH

which result from temperature changes will be noticed.

• Avoid rubbing or wiping electrode bulb, to reduce chance of

error due to polarization.

• After use in especially dirty or viscous samples or when

electrode response becomes sluggish, empty the electrode

completely and hold the junction open under running water.

Empty any water from the electrode and refill with fresh ROSS

Filling Solution. Briefly flush the junction to ensure that the

junction contains fresh filling solution. Maintain a proper level

of filling solution.

Figure 5: measuring Hints

Filling hole should

be uncovered

Fresh pH buffer

Stir all samples

and buffers

Filling solution level

must be higher than

sample level

Reference junction

must be immersed

Place insulation

between stirrer

and beaker