Sensor Adjustment - Ahlborn ALMEMO 2470-1S Operating Instruction

10. Measuring operations
Setting to zero automatically deletes the maximum and minimum val-

ues for this channel. The MAX, MIN, and MEM functions are thus
also available for relative measuring.

10.6 Sensor adjustment

Many types of sensor need to be adjusted either once or at regular intervals to
compensate for various instabilities.
With dynamic pressure probes (ranges L840 and L890, units Pa) the zero-
point must be temporarily adjusted by repeatedly pressing
until switching off, even if the channel is locked.
With the following chemical probes automatic two-point adjustment can be
performed :
Probe
pH probe
Conductivity
saturation FY A640-O2
O
2
1. Zero-point adjustment
To perform zero-point adjustment the measured value must first be physic-
ally set to zero. i.e.
● Immerse pH probe in a buffer solution, pH 7.0.
● Withdraw conductivity probe from the liquid and dry it.
● Hold the O probe for water in a zero solution.
2
Zero-point adjustment is performed in several steps.
To start the adjustment procedure press
If the sensor is locked, an abbreviation ap-
pears with the locking mode e.g. ´VM5´ and
the symbol FREE flashes. To temporarily
unlock the sensor for the purpose of ad-
justment, this must either be confirmed by
pressing key
pressing key
As soon as it has been confirmed the set-
point value flashes in the display with the correction symbol.
The adjustment itself must now either be confirmed once again by pressing
►
key (OK) or canceled by pressing key
28 ALMEMO 2470
Type
ZA 9610-AKY
FY A641-LF
FY A641-LF2
FY A641-LF3
►
(OK) or canceled by
◄
(ESC).
Zero- Gain
point
7.00 4.00
pH or
10.00
pH
0.0 2.77 mS/cm
0.0 147.0 uS/cm
0.0 111.8 mS/cm
0 101 %
PROG
◄
,
PROG
(ESC).
►
, i.e.