Hanna Instruments HI 98121 pH, redox and temperature measurement equipment, (- 2) - 16 pH HI 98121 Leaflet

Product codes
HI 98121
Page of 2
Taking measurements
Select ORP mode with the SET/HOLD button.
Submerge the electrode in the solution to be tested.
The measurements should be taken when the stability
symbol 
 on the top left of the LCD disappears.
The ORP (mV) value is shown
on the primary LCD while the
secondary LCD shows the tem-
perature of the sample.
The ORP range is factory calibrated
Contact your nearest Hanna Service Center for
recalibration, if necessary.
ELECTRODE MAINTENANCE
• When not in use, rinse the electrodes with water to
minimize contamination and store them with a few
drops of HI 70300 storage solution in the protective
cap after use. DO NOT USE DISTILLED OR DEION-
IZED WATER FOR STORAGE PURPOSES.
• If the electrodes have been left dry, soak in storage
solution for at least one hour to reactivate them.
• To prolong the life of the electrodes, it is recom-
mended to clean them monthly by immersing them in
the  HI 7061 cleaning solution for half an hour.
Afterwards, rinse it thoroughly with tap water and
recalibrate the meter.
• The pH electrode can be easily replaced by using
the supplied tool (HI 73128). Insert the tool into the
probe cavity as shown below.
Rotate the electrode counterclockwise.
Pull the electrode out by using the other side of the tool.
Insert a new pH electrode following the above instruc-
tions in reverse order.
To turn the meter on and to check battery status
Press and hold the 
/MODE button until the LCD
lights up. All the used segments on the LCD will be
visible for 1 second (or as long as the button is
pressed), followed by the percent indication of the
remaining battery life (E.g. % 100 BATT).
To freeze the display
While in measurement mode,
press the SET/HOLD button until
HOLD appears on the secondary
display. The reading will be fro-
zen on the LCD.
Press any button to return to normal mode.
To turn the meter off
While in measurement mode, press the 
/MODE
button. OFF will appear on the secondary display.
Release the button.
Note: If measurements are taken in different samples
successively, rinse the probe thoroughly to eliminate
cross-contamination; and after cleaning, rinse the
probe with some of the sample to be measured.
OPERATIONAL GUIDE
ORP MEASUREMENTS
Setup mode allows the selection of temperature unit
and pH buffer set.
To enter the Setup mode, select pH mode and then
press the 
/MODE button until CAL on the second-
ary display is replaced by TEMP and the current
temperature unit (E.g. TEMP °C). Then:
•  for °C/°F selection: Use the SET/HOLD button.
After the temperature unit has been selected, press the
/MODE button to enter the buffer set selection
mode; press the 
/MODE button twice to return to
the normal measuring mode.
•  to change the calibration buffer set: After setting
the temperature unit, the meter will show the current
buffer set: “pH 7.01 BUFF” (for 4.01/7.01/10.01) or
“pH 6.86 BUFF” (for NIST 4.01/6.86/9.18). Change
the set with the SET/HOLD button, then press 
/MODE
to return to the normal measuring mode.
SETUP
SPECIFICATIONS
Range
Resolution
Accuracy
(@20°C/68°F)
Typical  
EMC
Deviation
Temp. 
 Compensation
Environment
Calibration
Electrode
Battery 
 Type/Life
Auto-off
Dimensions
Weight
pH MEASUREMENTS & CALIBRATION
BATTERY REPLACEMENT
The meter displays the remaining battery percentage
every time it is switched on. When the battery level is
below 5%, the 
-    +
 symbol on the bottom left of the LCD
lights up to indicate a low battery condition. The batter-
ies should be replaced soon. If the battery level is low
enough to cause erroneous readings, the meter shows
“0%” and the Battery Error Prevention System (BEPS) will
automatically turn the meter off.
To change the batteries, remove the 4 screws located on
the top of the meter.
Once the top has been removed, carefully replace the 4
batteries located in the compartment while paying atten-
tion to their polarity.
Replace the top, making sure that the gasket is properly
seated in place, and tighten the screws to ensure a
watertight seal.
Taking measurements
Select pH mode with the SET/HOLD button.
Submerge the electrode in the solution to be tested
while stirring it gently.
The measurements should be taken when the stability
symbol  
 on the top left of the LCD disappears.
The pH value automatically com-
pensated for temperature is
shown on the primary LCD
while the secondary LCD shows
the temperature of the sample.
Note: Before taking any pH measurement make sure
the meter has been calibrated (CAL tag present on
the LCD).
pH Calibration
For better accuracy, frequent calibration of the instru-
ment is recommended. In addition, the instrument
must be recalibrated whenever:
a) The pH electrode is replaced.
b) After testing aggressive chemicals.
c)
Where high accuracy is required.
d) At least once a month.
Calibration procedure
From normal measuring mode, press and hold the
/MODE button until OFF on the secondary LCD is
replaced by CAL. Release the button. The LCD enters
the calibration mode displaying “pH 7.01 USE” (or
“pH 6.86 USE” if the NIST buffer set was selected).
After 1 second the meter activates the automatic buffer
recognition feature. If a valid buffer is detected then its
value is shown on the primary display and REC
appears on the secondary LCD. If no valid buffer is
detected, the meter keeps the USE indication active for
12 seconds, and then it replaces it with WRNG,
indicating the sample being measured is not a valid
buffer.
• For a single-point calibration with buffers pH 4.01,
9.18 or 10.01, the meter automatically accepts the
calibration when the reading is stable; the meter
displays the accepted buffer, with the message “OK
1”. After 1 second the meter automatically returns to
the normal measuring mode.
If a single-point calibration with buffer pH 7.01 (or
pH 6.86) is desired, then after the calibration point
has been accepted the 
/MODE button must be
pressed in order to return to normal mode. After the
button is pressed, the meter shows “7.01” (or “6.86”)
- “OK 1” and, after 1 second, it automatically returns
to the normal measuring mode.
Note: It is always recommended to carry out a two-
point calibration for better accuracy.
• For a two-point calibration, place the electrode in
pH 7.01 (or pH 6.86) buffer. After the first calibration
point has been accepted, the “pH 4.01 USE” message
appears. The message is held for 12 seconds, unless a
valid buffer is recognized. If no valid buffer is recog-
nized, then the WRNG message is shown. If a valid
buffer (pH 4.01, pH 10.01, or pH 9.18) is detected,
then the meter completes the calibration procedure.
When the buffer is accepted, the LCD shows the
accepted value with the “OK 2” message, and then
the meter returns to the normal measuring mode.
Note: When the calibration procedure is completed,
the CAL tag is turned on.
To quit calibration and to reset to the default
values
• After entering the calibration mode and before the
first point is accepted, it is possible to quit the
procedure and return to the last calibration data by
pressing the 
/MODE button. The secondary LCD
displays “ESC” for 1 second and the meter returns to
the normal measuring mode.
• To reset to the default values and clear a previous
calibration, press the SET/HOLD button after entering
the calibration mode and before the first point is
accepted. The secondary LCD displays “CLR” for 1
second, the meter resets to the default calibration and
the CAL tag on the LCD disappears.
-2.00 to 16.00 pH
±1000 mV
-5.0 to 60.0°C / 23.0 to 140.0°F
0.01 pH
1 mV
0.1°C or 0.1°F
±0.05 pH
±2 mV
±0.5°C or ±1°F
±0.02 pH
±2 mV
±0.3°C or ±0.6°F
Automatic for pH
-5 to 50°C (23 to 122°F); RH 100%
pH: at 1 or 2 points with 2 sets of
memorized buffers (pH 4.01/7.01/
10.01 or pH 4.01/6.86/9.18)
ORP: factory calibrated
HI 73127 pH electrode (included)
4 x 1.5V with BEPS/typical 250 hours
After 8 minutes
163 x 40 x 26 mm (6.4 x 1.6 x 1.0”)
85 g (3.0 oz)
pH:
ORP:
Temp:
pH:
ORP:
Temp:
pH
ORP:
Temp:
pH:
ORP:
Temp: