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APT4000PH
Product calibration
Calibration by sampling
During product calibration the electrode remains in the process.
The measurement process is only interrupted briefly.
Procedure:
During sampling the currently measured value is
stored in the APT4000PH. The APT4000PH immediately returns
to measuring mode. The calibration mode indicator flashes and
reminds you that calibration has not been terminated.
The sample is measured in the lab or directly on the site using
a portable meter. To ensure an exact calibration, the sample
temperature should correspond to the measured process tem-
perature. The sample value is then entered in the APT4000PH.
From the difference between the stored measured value and
entered sample value, the APT4000PH calculates the new
asymmetry potential (one-point calibration).
If the sample is invalid, you can take over the value stored dur-
ing sampling. In that case the old calibration values are stored.
Afterwards, you can start a new product calibration.
Display
Action
Remark
Product calibration step 1:
Press
CAL
key,
enter code 1105
(Select with
key,
edit number with
key,
proceed with
ENTER
)
Take sample and store value.
Proceed with
ENTER
If an invalid code is
entered, the
APT4000PH returns
to measuring mode.
Now the sample can
be measured in the
lab.
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Display
Action
Remark
Measuring mode:
From the flashing CAL mode indi-
cator you see that sample calibra-
tion has not been terminated.
Product calibration step 2:
When the sample value has been
determined, call up the product
calibration once more
(
CAL
, code 1105).
Display
(approx. 3 sec)
Enter lab value. The new asym-
metry potential is calculated.
While the sample
value is determined,
the APT4000PH is in
measuring mode.
Display of slope and new
asymmetry potential
(related to 25°C).
End calibration with
ENTER
.
The measured value is shown in
the main display alternately with
“Hold”; “enter” flashes.
End with
ENTER
.
After end of calibra-
tion, the outputs
remain in Hold mode
for approx. 20 sec.
New calibration:
Press
CAL
.
