PART THREE - OPERATION
SECTION 3 - ANALYZER CONFIGURATION
Model P33 pH/ORP Analyzer (panel-mount 1/4 DIN)
Rev. 6-1100
38
SET ISO POINT
(isopotential for special
Differential pH sensor)
☞
SET FILTER Time
2.
Press
ENTER key
to display a screen like
. Use
Ø
Ø
and
×
×
keys
to view the
three choices (NONE, AMMONIA or MORPHOLINE).
3.
With the desired choice displayed, press
ENTER key
to
enter this selection.
This configuration setting only applies to GLI Differen-
tial pH sensors that contain a special “standard cell”
buffer.
GLI Differential pH sensors normally contain 7.00
pH “standard cell” buffer, providing a theoretical output of
zero mV at exactly 7.00 pH. This relationship is called the
“isopotential.” A sensor with the normal 7.00 pH isopotential
provides (-) 59.9 mV per pH at process values higher than
7.00 pH and (+) 59.9 mV per pH at process values lower
than 7.00 pH. Special applications may require the sensor
to have a special isopotential such as 6.50 pH. For best ac-
curacy, set the analyzer to match the isopotential value of
the special GLI Differential pH sensor.
NOTE:
Changing the isopotential setting always requires
you to re-calibrate the analyzer. When using a con-
ventional combination electrode, the isopotential
setting is irrelevant and does not apply.
1.
With the
screen displayed, press
Ø
Ø
key
once to display
.
2.
Press
ENTER key
to display a screen like
. Use
arrow keys
to adjust the
displayed value to match the sensor’s isopotential, and
press
ENTER key
to enter the value.
A time constant (in seconds) can be set to filter or “smooth
out” the sensor signal. A minimum value of “0 seconds” has
no smoothing effect. A maximum value of “60 seconds” pro-
vides maximum smoothing. Deciding what sensor signal
filter time to use is a compromise. The higher the filter time,
the longer the sensor signal response time will be to a
change in the actual process value.
