User Guide

• Press the CAL key and the calibration process is ended with only

the offset of the meter calibrated. For best accuracy however, do

not press CAL and proceed with a two-point calibration.

TWO-POINT CALIBRATION

After calibrating at 6.86 or 7.01 pH (see above), for the second buffer

use pH 4.01 if you are going to measure acidic samples, and pH 9.18

or pH 10.01 if you are going to measure alkaline solutions.

• Proceed as described in "One-point calibration" above but do not

end the calibration by pressing CAL.

• After the first calibration point is confirmed, immerse the pH

electrode into the second buffer solution (pH 4.01, 9.18 or 10.01)

and stir gently.

Note: the electrode should be submerged approximately 4 cm (1½")

into the solution with the temperature probe located as close to

it as possible.

• Select the second buffer value on the secondary display by press-

ing the

°C or Ð

°C°C

°C key.

• When the “READY” and “CON” symbols blink on the display, the

reading is stable and the calibration can be confirmed.

• Press the CFM key. If the reading is not close to the selected buffer

solution, “WRONG

BUF

” and “WRONG ” will blink alternatively.

If the reading is close to the selected buffer, the slope and the

offset are calibrated. The values will be stored in memory and the

meter will return to the operating mode.

Note: The meter will automatically skip the buffer that was used for

the first calibration to avoid erroneous calibration. At least 1

full pH unit is required between the two buffers used for the

offset and slope calibration. As a result, once calibrated at

either pH 6.86 or 7.01, the microprocessor will automatically

ignore the other one for the second point calibration and it will

do likewise for pH 9.18 and 10.01

Note: During calibration, the secondary LCD displays the selected

buffer value.