EUTECH INSTRUMENTS 2700 Instrukcja Obsługi Pobierz pdf (Strona 16)

5. pH Calibration (with preset buffer group)

For best results, periodic calibration with known accurate standards is

recommended prior to measurement. Calibrate with standards that bracket your

intended measuring range while including a neutral point (7.00, 6.86, or 6.79). For

example, if you expect to measure samples from pH 6.2 to 9.5, calibration with

4.01, 7.00, and 10.01 will work well.

The 2700 series meters can be calibrated with up to 5 preset or custom buffers

(up to 6 with

DIN buffer group). The non-volatile memory retains all calibration

values upon meter shut down.

The 2700 series automatically recognizes the following pH calibration buffers in

the grou

ps listed below. See Section4—Buffer

to select a different buffer group;

Buffer Group pH Values

USA 1.68, 4.01, 7.00*, 10.01, 12.45

NIST 1.68, 4.01, 6.86*, 9.18, 12.45

DIN 1.09, 3.06, 4.65, 6.79*, 9.23, 12.75

USER 1 1.68, 4.01, 7.00*, 9.18, 12.45

USER 2 1.68, 4.01, 6.86*, 10.01, 12.45

CUSTOM Any 2 - 5 values, ≥ 1.0 pH unit apart

*Required as 1

calibration point value (offset determination)

To eliminate temperature errors associated with the pH electrode, attach the

automatic te

mperature compensation (ATC) probe for best accuracy. Without

temperature compensation, pH accuracy will worsen as samples deviate from

25ºC and pH 7.

If the pH electrode has been stored dry, soak in storage solution for 10 minutes

before

calibrating or taking readings to saturate the pH electrode surface and

minimize drift. If storage solution is not available, use a neutral pH buffer. Do not

reuse buffer solutions after calibration. Contaminants in the solution can affect the

calibration, and eventually the accuracy of the measurements.

1) Turn meter on, press

MODE if needed for pH Measurement.

2) Rin

se the pH and ATC electrodes with clean water then submerse in neutral

pH buffer—the 1st calibration point must be either 7.00, 6.86, or 6.79

depending on the buffer group used.

3) Press

CAL to enter calibration mode.

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