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CONNECTIONS
pH ELECTRODE CONNECTION
• Connect the pH electrode to the BNC connector (#3) and
the Matching pin to the PM terminal.
EC PROBE CONNECTION
• Probe wires are colour coded for an easy installation:
Terminal
Probe Wire Color
EC probe #1
Green
EC probe #2
White
EC probe #3
Red
EC probe #4
Blue
Temperature sensor #1
Brown
Temperature sensor #2
Grey
Shield
Yellow-green
POWER CONNECTION
• Connect a 2-wire cable to the 12-24 Vdc power source,
while paying careful attention to its polarity.
OUTPUT CONNECTION
• Connect a 2-wire cable from the pH output terminals
(#8) to the pH receiver, and another 2-wire cable from
the EC output terminals to the EC receiver, while paying
attention to the polarity. Outputs vary proportionally to
the measured pH and EC values in the range of 0-1 V (for
HI 98143-01), 0-4 V (for HI 98143-04) or 4-20 mA (for
HI 98143-20 and HI 98143-22).
OPERATIONAL GUIDE
•
HI 98143 may be wall-mounted at any convenient
location close to the measurement site. To minimize ther-
mal drifts due to extreme temperature fluctuations, it is
recommended to protect transmitter inside a casing.
• Connect probes, power supply and receiving devices to the
HI 98143 as explained in the previous section.
• Remove the protective cap from the pH electrode and
immerse it at least 4 cm into the sample.
• If the matching pin is used, dip it together with
the pH electrode; if it is not used, connect the
matching pin terminal to the reference with a
jumper wire.
• Immerse the EC probe in the sample.
• For continuous flow-thru measurements, the probes can be
easily installed in any standard ½" pipe tee. Use Teflon
tape between the probe and the pipe to ensure a leak
free joint. Take care not to overtighten it, as excessive
pressures can cause probe damage.
Note: To prevent any damage, disconnect the pH electrode
before turning the meter off.
PROBE MAINTENANCE
pH ELECTRODE MAINTENANCE
• Do not be alarmed if white crystals appear around the electrode
protective cap. This is normal with pH electrodes and they dissolve
when rinsed with water.
• When not in use, rinse the electrode with tap water and store it with a
few drops of storage (HI 70300) or pH 7 (HI 7007) solution in the
protective cap.
NEVER USE DISTILLED OR DEIONIZED WATER FOR STORAGE PUR-
POSES.
• If the electrode has been left dry, soak the tip in a storage (HI 70300)
or pH 7 (HI 7007) solution for at least one hour to reactivate it.
• To minimize clogging and provide longer life for the pH electrode, it
is recommended to clean it monthly. Immerse the tip of the elec-
trode in HI 7061 for one hour and then rinse it with tap water.
EC PROBE MAINTENANCE
• When calibration can no longer be achieved, remove conductivity
probe from the system for maintenance.
• Rinse the probe with tap water. If a more thorough cleaning is de-
sired, remove the plastic protective sleeve and clean the platinum
sensors with a non-abrasive cloth soaked in HI 7061 cleaning solu-
tion. Reinsert the sleeve, while paying
attention that the sleeve hole touches the
threaded edge.
CALIBRATION
®
For better accuracy, frequent calibration of the instrument is recommended.
Calibration should also be performed whenever the pH electrode is re-
placed, after testing aggressive chemicals or at least once a month.
pH CALIBRATION
Pour small quantities of pH 7.0 (HI 7007) and pH 4.0 (HI 7004) or
pH 10.0 (HI 7010) solutions into two clean beakers. Use pH 4.0 solu-
tion as second calibration buffer if you are measuring acidic samples,
while pH 10.0 solution is recommended for alkaline solutions.
• Connect a multimeter to the pH output terminals and set it to voltage
(HI 98143-01 and HI 98143-04) or current (HI 98143-20 and
HI 98143-22) readings.
• Turn the transmitter on. Rinse and immerse pH elec-
trode and matching pin (if used) in pH 7.0 buffer.
Stir gently and wait for the reading to stabilize.
• Adjust the pH offset calibration trimmer with a small
screwdriver until the multimeter displays:
500 mV for HI 98143-01
2.00 V for HI 98143-04
12.00 mA for HI 98143-20 and HI 98143-22.
• Rinse and immerse pH electrode and matching pin (if used) in
pH 4.0 (or pH 10.0) buffer and stir gently.
• Wait a couple of minutes and then adjust the pH slope trimmer until
the multimeter shows the value of the second buffer:
model
pH 4 buffer
HI 98143-01
286 mV
HI 98143-04
1.14 V
HI 98143-20
8.57 mA
HI 98143-22
8.57 mA
The pH calibration is now complete.
EC CALIBRATION
• Connect a multimeter to the EC output terminals and set it to voltage
(HI 98143-01 and HI 98143-04) or current (HI 98143-20 and
HI 98143-22) readings.
• Turn the transmitter on.
• Leave the HI 3001 EC probe in air (dry probe), and adjust the EC
offset calibration trimmer with the calibration screwdriver until the
multimeter displays:
0 mV for HI 98143-01 and HI 98143-04
4.00 mA for HI 98143-20 and HI 98143-22.
• Pour a small quantity of 5.00 mS/cm (HI 7039) calibration solu-
tion in a plastic beaker and immerse completely the tip of the EC
probe into the solution.
• Tap the probe repeatedly on the bottom of the beaker and stir it to
ensure that no air bubbles are trapped inside the sleeve. In the case
of in-line applications, to better simulate the installation ambient,
the probe tip should be close to the beaker bottom edge.
• Allow the reading to stabilize and adjust the EC slope calibration
trimmer to read on the multimeter:
500 mV for HI 98143-01
2.00 V for HI 98143-04
12.00 mA for HI 98143-20 and HI 98143-22.
The EC calibration is now complete.
OUTPUT
HI 98143-01 and HI 98143-04:
The input is isolated from output and
power supply. The outputs aren't isolated
from power supply.
HI 98143-20:
The output must be feed by an external power supply, which
can be the same used for the meter. Carefully follow the first
connection diagram.
If an additional power supply is used to feed the inputs,
follow the second connection schema. Note that the negative
sockets are connected with the negative power supply.
pH 10 buffer
714 mV
2.86 V
15.43 mA
15.43 mA
HI 98143-22:
Carefully follow this connection
diagram for active current out-
put calibration.
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