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2 ph calibration, 1 why calibrate, 2 when do you have to calibrate – Xylem MultiLab 4010-2 User Manual

Page 29: 3 carrying out automatic calibration (autocal), Ph calibration, Why calibrate, When do you have to calibrate, Carrying out automatic calibration (autocal)

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MultiLab 4010-2

pH value

ba76142e01

05/2013

29

The display of the temperature indicates the active temperature measuring
mode:

5.2

pH calibration

5.2.1 Why calibrate?

pH electrodes age. This changes the zero point (asymmetry) and slope of the
pH electrode. As a result, an inexact measured value is displayed. Calibration
determines and stores the current values of the zero point and slope of the
electrode.
Thus, you should calibrate at regular intervals.

5.2.2 When do you have to calibrate?

Routinely within the framework of the company quality assurance

When the calibration interval has expired

5.2.3 Carrying out automatic calibration (AutoCal)

Make sure that in the sensor menu, Buffer menu, the buffer set is correctly
selected (see section 9.1.1 S

ETTINGS

FOR

P

H

MEASUREMENTS

, page 61).

Use one to five buffer solutions of the selected buffer set in any order.

Below, calibration with YSI buffers (YSI) is described. When other buffer sets
are used, other nominal buffer values are displayed. Apart from that, the proce-
dure is identical.

Temperature
sensor

Resolution of the
temp. display

Temp. measurement

Yes

0.1 °C

Automatic with temperature
sensor

-

1 °C

Manual

If single-point calibration was set in the menu, the calibration proce-
dure is automatically finished with the measurement of buffer solu-
tion 1 and the calibration record is displayed.

1.

Connect the pH sensor to the meter.
The pH measuring window is displayed.

2.

Keep the buffer solutions ready.
When measuring without temperature sensor:
Temper the buffer solutions or measure the current temperature.

3.

Start the calibration with .
The calibration display for the first buffer appears (voltage display).