Hanna Instruments HI 504920 - Manual (Page 6)

11 10
USE AS REFERENCE pH METER
HI 504910 QUICK pH CALIBRATION
HI 504910 can be calibrated frequently through HI 504920 without
interrupting the normal measurement.
This is accomplished through a single point pH calibration at the pH
value of the solution monitored by HI 504910.
Perform the following steps:
1. Connect the supplied infrared optical interface cable (HI 7290) to
the calibrator and to the HI 504910 Digital Transmitter.
2. Immerse the pH electrode into the solution which HI 504910 is
measuring, as close as possible to the HI 504910 pH probe. Wait
a few seconds for the electrode to stabilize.
3. When the meter displays pH measure-
ment, press TXCAL on the HI 504920
calibrator.
4. The LCD will display "CALt" for a couple of
seconds to indicate that the calibration
of the HI 504910 transmitter is in
progress.
5. If the calibration is completed correctly,
the LCD will flash the "Good" message for
a couple of seconds.
6. The primary LCD then shows the pH
reading of the HI 504910 transmitter,
while the secondary one displays the pH
reading of the reference meter. Both pH tags blink alternatively.
Note: The two values may differ a little if the solution under
measurement is not stable. For an accurate calibration, it is
recommended to perform the above procedure only when
readings are stable.
7. To exit the calibration mode and return
to normal measurement, press TXCAL.
mV CALIBRATION
Contact your nearest Hanna Service Center for periodic mV calibration.
It is recommended to have the meter recalibrated for mV reading at
least every two years.
TEMPERATURE CALIBRATION
(for technical personnel only)
Contact your nearest Hanna Service Center for periodic temperature
calibration.
It is recommended to have the meter recalibrated for temperature
reading at least every two years.
Temperature calibration at your site should be performed only by
skilled technical personnel as described in the following procedure
(two-point calibration at 0.0 and 50.0°C):
1. Immerse the pH electrode with the built-in temperature sensor in
a 0°C ice bath.
2. Press (ALT+) CALT to enter temperature calibration mode.
3. Enter the password.
4. The meter will display "0.0°C" on the secondary LCD with the
"BUF 1" and "CAL" indications.
5. When the reading is stable the "CFM" tag starts blinking.
6. Press CFM to confirm. The secondary LCD will then display
"50.0°C" with the "BUF 2" indication.
7. Immerse the pH electrode with the built-in temperature sensor in
a 50°C bath.
8. When the reading is stable the "CFM" tag starts blinking.
9. Press CFM to confirm, save the new calibration data and return to
normal mode.
Note: To abort the calibration procedure and leave the calibration data
unchanged, press (ALT+) CALT at any time before the last step.