Eltek Squirrel 1000 Series - 9. pH Channel Setup; Channel Selection and Temperature Compensation

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9. Squirrels with pH channels
Some Squirrels have pH inputs. Such inputs require individual two-point
calibration, and temperature compensation. The Squirrel supports two
types of temperature compensation - measured and pre-set.
9.1 Channel Selection
The pH channels have two ranges available. These are actually both the
same range; the difference is where the temperature compensation
comes from. Choose from the pre-set temperature (which can be altered
in the STAT function), or from the associated temperature channel (as
illustrated below). If the latter is chosen, one of the -50°C to +150°C
ranges of the temperature channel must also be selected otherwise the
logger will perceive this as an error and switch the range to use the pre-
set compensation. In this situation, the display will show ‘INVALID –
CHECK!’ to alert the user that this has happened.
C
H
9
p
H
(
c
h
1
)
0
.
0
/
1
4
.
0
It is worth noting that if the temperature channel is selected but no probe
is plugged in, then compensation will again be taken from the pre-set
value. In this case, the pH ‘range’ is unchanged; the temperature input
would still be used if it were connected.
9.2 Pre-setting the Temperature
If the temperature of all the pH probes is known to be constant (or if high
accuracy is not required) then it is not necessary to use a temperature
probe for compensating the pH probe. The temperature of the pH probe
can be set in the STAT function.
S
T
A
T
p
H
t
e
m
p
2
0
.
0
°
C
Press and hold set to change the value. The longer set is pressed the
faster the value changes.