4220 Flow Meter
Section 5 Options and Accessories
5-14
3. Now go to step 3. PARAMETER TO ADJUST - NONE,
LEVEL, pH. (Other selections may appear.) Select pH. If
the pH menu does not appear in step 3, go back to step 1 to
make sure you have turned it on. Then the pH selection of
calibrations will appear.
4. Place the pH probe in the appropriate buffer solution until
the stainless steel body is one inch beneath the surface.
5. If you select 4 & 7, the followin g will appear. Calibration
with the other menu options (7 & 10 or 4, 7, & 10) is essen-
tially the same as shown below. For the other menus, see
Section 2.
6. Wait for the reading to stabilize (this may take from 30 sec-
onds up to five minutes). When the probe has stabilized,
press Enter and the following display will appear:
When you have entered this second value, the pH probe
calibration is complete. You can then install the probe in
the flow stream.
Note
An asterisk (*) may occasionally appear next to the pH reading
for approximately 30 seconds, during which time the most
recent reading will be displayed. This may be normal flow
meter operation due to other internal functions, or could indi-
cate pH fluctuation in the stream.
5.9.2 pH Probe Installation
Guidelines
Installation of the pH probe is similar to the submerged level
sensor and other parameter probes.
• Install the probe only in streams that have continuous
flow. The sensing end of the probe must always remain
wet.
• For proper operation, there must also be enough flow to
submerge the sensing end of the probe completely.
If flow in the stream is intermittent (dry for periods of time), the
pH sensing bulb will dry out and its response time will slow. This
is a problem in situations where pH changes rapidly. If the probe
is dry long enough, it will first lose sensitivity, then be slow to
respond, and finally stop working. Never let the sensing end of
the probe dry out completely.
• Installation in streams with high grease content will
result in poor performance and require frequent
cleaning and recalibration.
RINSE PROBE AND PLACE IN 4.0 pH SOLUTION
PRESS ENTER WHEN STABLE: X.XX pH
RINSE PROBE AND PLACE IN 7.0 pH SOLUTION
PRESS ENTER WHEN STABLE: X.XX pH