2 measuring the ph value, Measuring the ph value – Xylem MULTI 1970I PORTABLE MULTIPARAMETER METERS User Manual

Page 21

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Multi 1970i

Operation

19

4.3.2

Measuring the pH value

AutoRead AR

(Drift control) and hold

function

The AutoRead function (drift control) checks the stability of the mea-
surement signal. The stability has a considerable impact on the repro-
ducibility of the measured values. With the aid of the hold function the
measured value display is frozen.

With identical measurement conditions, the following criterion is valid
for the AutoRead function:

For D. O. measurements, use the AutoRead function and hold function
like this:

1

Perform the preparatory activities according to section 4.3.1.

2

Immerse the pH electrode in the test sample.

3

Press the <

> <> keys repeatedly until pH appears on the

status display. The pH value appears on the display.

4

When measuring without a connected temperature sensor:
Options:
z Determine the current temperature using a thermometer

and, while keeping the <RUN/ENTER> key depressed, en-
ter this temperature value with <

> <>.

z TP display indicator not displayed, socket for the second

sensor is free:
Connect the second sensor (Oxi or Cond) and immerse it in
the same sample. TP flashes, the temperature is automati-
cally measured using the second sensor.

AR

1

LoBat

nLF

Lin

Oxi

Tref25

Tref20

Cal

TEC

ARng

Auto

Store

8

Time

Year

Ident

No.

Day.Month

Baud

Sal

cm

1/

K

/

%

RCL

REL2

pH

/

mV

m

cm

S/

%

mg/ l

Sal

O

S

pH

6

2 4 8

9 9

°

C

TP

REL1

Reproducibility

Response time

Better than 0.02

> 30 seconds

1

Call up the pH measuring mode with <

> <>.

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