Ph Probe Calibration; Parameter Module - Teledyne 4250 Installation And Operation Manual

4.10.1 pH Probe Calibration

parameter module to allow greater operating distance from the
flow meter. The flow meter determines the pH value and displays
it.
The 4250 provides a two- or three-point calibration for the pH
probes with commercially-prepared calibrated buffer solutions.
Calibrations of 4 and 7, 7 and 10, and 4, 7, and 10 are all possible.
For accurate readings you must clean and re-calibrate the probe
on a regular basis. How often you need to do this depends on the
condition of your flow stream. Flow streams with a high grease
content will coat the sensing surfaces of the probe quickly, clogging
them and slowing the response time or stopping it altogether.
Installation in very greasy flow streams is not recom-
mended.
Note
For pH probe calibration, Teledyne Isco recommends that you
use a glass container for the buffer solutions to ensure that the
following conditions are met:
The probe must be properly submerged in solution, and there
must be no air trapped under the probe membrane, or the
reading may become incorrect and/or erratic.
Do not touch the probe until after you have performed step 6.
To calibrate the pH probe with the flow meter:
1. Go to program Step 1: PROGRAM, SETUP and select
PROGRAM.
2. Step through the units of measure with the Enter key
until you reach the menu that says pH UNITS - NOT
MEASURED, pH. Select pH. You must do this in step 1 or
the pH menu will not appear later.
3. Now go to step 3. PARAMETER TO ADJUST - NONE,
LEVEL, pH (other selections may appear.) and 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 following screen will appear. Cali-
bration with the other menu options (7 & 10 or 4, 7, & 10)
is essentially the same as shown below. For the other
menus, see Section 2.
RINSE PROBE AND PLACE IN 4.0 pH SOLUTION
PRESS ENTER WHEN STABLE: X.XX pH
6. Wait for the reading to stabilize (this may take from 30 sec-
onds up to 5 minutes). When the probe has stabilized,
press Enter and the following display will appear:
4250 Flow Meter
Section 4 Options and Accessories
4-17