2 measuring the ph value, Measuring the ph value – Xylem MULTI 1970I PORTABLE MULTIPARAMETER METERS User Manual
Page 21

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 <
▲> <▼>.