Ph Measurement; Ph Electrode Information; Ph Calibration Consideration - Standard Buffer Solution; Three-Point Calibration - Dostmann pH 7+ Manual Del Usuario

pH Measurement

pH electrode information

On this meter is possible to use electrode with integrated temperature sensor else link two different probes for pH and
temperature.
The BNC socket of electrode connects pH socket, RCA socket connects temperature socket. When dip the electrode in
the solution, please stir the solution briefly and allow it to stay in the solution until a stable reading is reached.
pH calibration consideration
The meter uses two series of standard buffer solution: USA series and NIST series, and also customer-defined solution.
Please see the table below for the two series of standard buffer solution. For customer-defined solution, please select it
in setup menu parameter P1.1.
Icons

Three-point calibration

Three-point calibration
The instrument can perform 1-3 point calibration. The first point of calibration must be 7.00 pH (or 6.86 pH) standard
solution, then select other standard solution to perform the second and the third point calibration; the meter is able to
recognize the buffer solutions in analysis. During the calibration process, the instrument displays the slope of acidity
range and alkalinity range respectively.
One-point calibration
Two-point calibration
Three-point calibration

Calibration Intervals

Calibration intervals depend on the sample, the electrode performance, and the required accuracy. For high accuracy
measurements (≤ ±0.02pH), the meter should be calibrated immediately before taking a measurement. For general
accuracy (≥±0.1pH), the meter can be calibrated and used for approximately one week before the next calibration.
The meter must be recalibrated in the following situations:
(a) New probe, or probe that is unused for a long period of time
(b) After measuring acids (pH<2) or alkaline solutions (pH>12)
(c) After measuring a solution that contains fluoride or a concentrated organic solution
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Standard buffer solution
USA standard
7.00 pH
7.00 pH and
4.00 pH or 1,68 pH
7.00 pH and 10.01 pH
7.00 pH, 4.00 pH or 1,68
pH, 10.01 pH
pH standard buffer solution series
USA series
1,68 pH and 4.00 pH
7.00 pH
10.01 pH
NIST standard
6.86 pH
6.86 pH and
4.01 pH or 1,68 pH
6.86 pH and 9.18 pH
6.86 pH, 4.01 pH or
1,68 pH, 9.18 pH
9
NIST series
1,68 pH and 4.01 pH
6.86 pH
9.18 pH
Icons Suited range
Accuracy
≤ ±0.1pH
Range<7.00pH
Range>7.00pH
Large Range
EN