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OPERATION
5.
Turning the meter on
Press and hold the MODE button until the display switches on. First of all, an LCD self-test is
performed in which all the used segments on the LCD will be visible for a few seconds. After
that, the charge state of the batteries appears in % (e.g. %100 BATT).
Changing the temperature measuring range
To switch from °C to °F, press the MODE button in measurement mode (ignore the OFF
display) until TEMP and the set temperature unit appear on the display, e.g. TEMP °C. To
switch, press the SET/HOLD button and then the MODE button twice to return to measure-
ment mode.
"Freezing" a measured value
Press the SET/HOLD button until HOLD appears on the secondary display. Press the HOLD
button again. The meter switches back to measurement mode.
Turn the meter off
In measurement mode, press the MODE button. OFF appears on the display. Release the
button. The device switches off.
Notes
The calibration interval depends on the measurement behaviour. A 2-point calibration
ensures the highest accuracy. If you want to measure several samples in a row, rinse the
electrode thoroughly with the next sample and then perform the measurement. At the end
of each measurement series, clean the sensors with tap water and wet the pH electrode
with a few drops of storage solution
6. pH MEASUREMENT AND CALIBRATION
Performing a pH measurement
Set the pH measurement mode by pressing the SET/HOLD button. Im-
merse the electrode in the sample solution. The displayed value can be
read as soon as it is stable.
The pH reading is displayed temperature-compensated.
Selection of standard buffer series
This function determines which pH buffers are required for calibration.
In measurement mode, press and hold the MODE button until TEMP and
the current temperature unit appear on the display, e.g. TEMP °C. Press
SET/HOLD to switch the set. Press the MODE button again. The current
buffer set appears on the display: pH 7.01BUFF (for pH 4.01/7.01/10.01)
or pH 6.86BUFF (for the series 4.01/6.86/9.18). Confirm your choice
using the MODE button. The measuring device switches back to meas-
urement mode.
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7. pH CALIBRATION
pH calibration
Turn the meter on. Press and hold the MODE button until CAL appears on the display.
Ignore the OFF display. Now release the button. pH 7.01 USE or pH 6.86 USE appears on the
display. Automatic buffer detection is now active.
1-point calibration
Please proceed as follows for a 1-point calibration: immerse the electrode in one of the
previously selected buffer solutions (e.g. pH7.01, pH 4.01 or pH 10.01). The device auto-
matically detects the buffer if the measured value does not deviate by more than +/-0.4 pH
units from that of the calibration buffer. The probe must be cleaned or replaced in case of
larger deviations.
When using the buffer pH 4.01 or pH 10.01, the device displays OK for about 1 second and
then returns to measurement mode. If you use the pH 7.01 solution, the device - after
detection - requests the buffer pH4.01 for a 2-point calibration. Press the MODE button
to return to measurement mode or continue the calibration at the 2nd point as explained
below.
2-point calibration
A 2-point calibration ensures higher accuracy over a wide pH range. Please proceed as
follows for a 2-point calibration: immerse the electrode in the pH 7.01 (or 6.86) buffer solu-
tion. The device detects the buffer value and then displays pH 4.01 USE. Rinse the electrode
thoroughly. Immerse the electrode in the second buffer solution (pH 4.01 or 10.01, pH 4.01
or 9.18). When the second buffer is detected, OK (1 second) appears on the display and the
device automatically returns to measurement mode. The CAL symbol is now active.
8. EC / TDS MEASUREMENT AND CALIBRATION
Immerse the electrode or probe in the solution to be tested. The displayed measured value
can be read as soon as it is stable. The EC/TDS measured value is automatically temperature
compensated. The displayed temperature reading corresponds to the actual temperature of
the measuring solution.
Calibration of the conductivity
During the measurement process, press and hold the MODE button until CAL appears on
the display (ignore the OFF display). Release the button and immerse the probes in the ap-
propriate calibration solution: HI 7031 * (1413 μS/cm) for HI 98129 and HI 7030 (12.88 mS/
cm) for HI 98130. Now the automatic buffer detection starts. The device automatically de-
tects the buffer if the measured value does not deviate by more than about +/- 4% from the
value of the calibration solution. The conductivity probe must be cleaned beforehand in the
event of larger deviations. If the automatic buffer detection is performed, OK appears for
one second on the display. The device then automatically reverts to measurement mode.
No recalibration is necessary when changing the measuring range from EC to TDS or TDS to
EC. The CAL symbol on the display indicates that the device is calibrated.
* The suitable calibration solution 1413 for conductivity meters is available, for example,
from accessories retailers on the Internet.
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