Hanna Instruments HI 99121 User manual

INSTRUCTION MANUAL
HI99121
Waterproof pH & Temperature Meter
for Direct Measurement in Soil

Thank you for choosing a Hanna Instruments product.
Please read this instruction manual carefully before using this meter.
This manual will provide you with the necessary information for correct use of
this meter, as well as a precise idea of its versatility.
If you need additional technical information, do not hesitate to e‑mail us at
[email protected] or view our worldwide contact list at www.hannainst.com.
All rights are reserved. Reproduction in whole or in part is prohibited without the written consent of the
copyright owner, Hanna Instruments Inc., Woonsocket, Rhode Island, 02895, USA.
Dear
Customer,

3
Preliminary examination .....................................................................................................
General description and Intended use ..................................................................................
Main features.....................................................................................................................
Specifications.....................................................................................................................
Display description .............................................................................................................
Operational guide...............................................................................................................
Meter setup........................................................................................................................
Soil pH..............................................................................................................................
Organic substrate ...............................................................................................................
Irrigation water ..................................................................................................................
Nutrient solution ................................................................................................................
Battery replacement............................................................................................................
Accessories.........................................................................................................................
Electrode maintenance........................................................................................................
Certification........................................................................................................................
Recommendations for users.................................................................................................
Warranty ...........................................................................................................................
TABLE OF CONTENTS
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PRELIMINARY EXAMINATION
GENERAL DESCRIPTION AND INTENDED USE
PRELIMINARY EXAMINATION
Remove the instrument and accessories from the packaging and examine it carefully to make sure
that no damage has occurred during shipping. Notify your nearest Hanna Instruments Customer
Service Center if damage is observed.
Each HI99121 is delivered in a rugged carrying case and is supplied with:
• HI12923 pH/temperature probe with conical tip, DIN connector and 1 m (3.3’) cable
• HI70004 pH 4.01 buffer (1 sachet)
• HI70007 pH 7.01 buffer (1 sachet)
• HI700663 cleaning solution for soil deposits (1 sachet)
• HI700664 cleaning solution for humus deposits (1 sachet)
• HI7051M soil sample preparation solution
• HI721319 auger for ground penetration, packed separately in a carton box
• 100 mL beaker (1 pc.)
• 1.5V AAA alkaline batteries
• Instrument quality certificate
• Electrode quality certificate
• Instruction manual
Note: Save all packing material until you are sure that the instrument works correctly. Any
damaged or defective item must be returned in its original packing material with the supplied
accessories.
GENERAL DESCRIPTION AND INTENDED USE
The HI99121 portable pH meter together with HI12923 pH electrode is designed to measure pH in
soil or soil slurries.
The HI99121 is a lightweight, portable pH and temperature meter. It features a two button operation
system and is simple to use. It has a waterproof and compact casing, large dual‑line display, and
automatic pH calibration at one or two points.
The HI12923 has a conical rugged tip. It has a built‑in temperature probe for temperature
compensated pH readings and an integrated preamplifier to provide measurements impervious to
noise and electrical interferences.
The HI721319 auger for ground penetration is supplied to loosen the soil prior to any measurements
being taken. The use of the auger is recommended to prevent scratching to the pH glass.

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MAIN FEATURES
MAIN FEATURES
• Simultaneous pH and temperature measurements on a large dual‑line LCD display
• Automatic pH calibration at one or two points within two memorized buffer sets (standard
or NIST)
• Selectable temperature unit (°C or °F)
• Electrode condition indicator
• mV of pH measurement for electrode check
• HI12923 dedicated pH probe with integrated temperature sensor
• Probe quick connect system
• Battery life indication and low battery detection
• Keystroke confirmation tone
• Auto‑off function
• Waterproof casing IP67

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SPECIFICATIONS
Range*
‑2.00 to 16.00 pH / ‑2.0 to 16.0 pH
±825 mV (pH‑mV)
‑5.0 to 105.0 °C/23.0 to 221.0 °F
Resolution
0.01 pH / 0.1 pH
1 mV
0.1 °C/0.1 °F
Accuracy
@ 25 °C / 68 °F
±0.02 pH / ±0.1 pH
±1 mV (pH‑mV)
±0.5 °C up to 60 °C; ±1.0 °C outside
±1.0 °F up to 140 °F; ±2.0 °F outside
Temperature compensation Automatic
‑5.0 to 105.0 °C/23.0 to 221.0 °F
pH calibration Automatic, 1 or 2 point selectable buffer set Standard (4.01, 7.01 10.01)
or NIST (4.01, 6.86, 9.18)
Probe (included) HI12923 preamplified pH and temperature probe with conical tip,
DIN connector and 1 m (3.3’) cable
Battery type/life 1.5V AAA (3 pcs.)
approx. 1400 hours of continuous use
Auto‑off user selectable: after 8 min, 60 min or disabled
Environment 0 to 50 °C (32 to 122 °F)
RH max. 100%
Meter dimensions 154 x 63 x 30 mm (6.1 x 2.5 x 1.2”)
Weight (with batteries) 196 g (6.91 oz.)
Case ingress protection rating IP67
* the HI12923 is limited to be used from 0 to 12 pH and from ‑5 to 70 °C temperature (23 to 158 °F).
SPECIFICATIONSDISPLAY DESCRIPTION
DISPLAY DESCRIPTION
1 Automatic Temperature Compensation indicator
2 Stability indicator
3 Battery percentage
4 Electrode condition indicator
5 Low battery indicator
6 Measurement unit
7 Primary LCD
8 Temperature unit
9 Secondary LCD
10 Meter modes indicator
11 pH calibration buffer(s) used

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OPERATIONAL GUIDE
OPERATIONAL GUIDE
Each meter is supplied with batteries. Before using the meter for the first time, open the battery
compartment and insert batteries, observing the polarity (see “Battery Replacement“).
CONNECTING THE ELECTRODE
With the meter turned off, connect the HI12923 probe to the DIN socket on the bottom of the meter
by aligning the pins and pushing in the plug firmly. Remove the protective cap from the probe before
taking any measurements.
TURNING THE METER ON
To turn the meter ON, press the button on the front of the meter. If it does not turn on,
make sure that the batteries are properly installed in their place. The meter is provided
with an active acoustic signal that confirms when a key is pressed. At start‑up the meter displays all
LCD segments for a few seconds, followed by the percentage indication of the remaining battery life,
displaying “WAIT” until electrode check is in process then the meter enters the normal measurement
mode.
Measurement
mode
Battery life
LCD
check up
→ →
→
Electrode
check
Note: The meter detects the presence and the type of the probe at its input.
- If the probe is not connected the message “NO” ”PROBE“ appears alternatively on the
secondary LCD with “---“ blinking on the first LCD line.
- If the probe is not compatible “WRONG” ”PROBE“ message appears alternatively on the
secondary LCD with “---“ blinking on the first LCD line.
- If the readings are out of range, the nearest range limits are displayed blinking (e.g. -2.00 pH
-5.0 °C).
SELECTING MEASUREMENT VALUES
While in measurement mode, press the SET button to select pH or pH‑mV measurement on the first
LCD line.

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OPERATIONAL GUIDE
pH MEASUREMENT & CALIBRATION
Make sure the meter has been calibrated before use. If the probe is dry, soak it in HI70300 storage
solution for 30 minutes to reactivate it. If soiled, clean the electrode by soaking in cleaning solution
for 20 minutes, then rinse the tip and soak in storage solution at least 30 minutes before use.
Rinse the electrode off well and shake off excess droplets. Recalibrate before using. Submerge the
probe in the sample to be tested while stirring it gently. Wait until the tag on the LCD disappears.
The LCD displays the pH value (automatically compensated for temperature)
on the primary LCD, while the secondary LCD displays the sample temperature.
If measurements are taken in different samples successively, rinse the probe
tip thoroughly in distilled or deionized water to eliminate cross‑contamination.
For better accuracy, frequent calibration of the pH sensor with the meter is recommended. In
addition, the meter must be recalibrated:
a) whenever the pH electrode is replaced.
b) after testing aggressive chemicals.
c) when high accuracy is required.
d) at least once a month.
e) after cleaning the sensor.
FREEZING MEASUREMENT VALUES
While in measurement mode, press and hold the SET button until “HOLD“ appears on the secondary
LCD. The “HOLD“ remains for 1 second and reading of pH, mV and temperature will be frozen on
the LCD with “H” blinking.
→
Press any button to resume active measurements.
ENTERING CALIBRATION MODE
Press and hold the button until ”POWER” and tag is replaced by “STD“ and tag.
Release the button.
ENTERING SETUP MODE
Press and hold button until “STD“ and tag is replaced by “SETUP“ and tag.
Release the button.
TURNING THE METER OFF
While in measurement mode, press the button.”POWER” and tag will appear. Release
the button.

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OPERATIONAL GUIDE
pH calibration
Enter calibration mode while in pH measurement mode. Place the sensor into the
first calibration buffer. If performing a two‑point calibration, use pH 7.01 (pH
6.86 for NIST) buffer first. The meter will enter the calibration mode, displaying
“pH 7.01 USE” and tag blinking (or “pH 6.86 USE” for NIST).
Follow directions for single and two‑point calibration below:
Single-point calibration
1. Place the probe in any buffer from the selected buffer set. The meter will automatically recognize
the buffer value.
2. If the buffer is not recognized or the calibration offset is out of the accepted range “---- WRONG“
is displayed.
3. If the buffer is recognized “REC“ is displayed then “WAIT“ until the calibration is accepted.
If using pH 7.01 (or pH 6.86 for NIST), after acceptance of the buffer press any key to exit. The
”SAVE” message is displayed and the meter returns to pH measurement mode.
If using pH 4.01 or 10.01 (or pH 9.18 for NIST) buffer the ”SAVE” message is displayed and
meter returns to pH measurement mode.
Two-point calibration
Proceed with steps 1 through 3 under single‑point calibration using 7.01 pH (pH 6.86 for NIST)
buffer first. Then follow steps below:
The ”pH 4.01 USE” message is then displayed.
Place the probe in the second calibration buffer (pH 4.01 or 10.01, or, if using NIST, pH 4.01
or 9.18). When the second buffer is accepted, the LCD will display “SAVE” for 1 second and the
meter will return to the normal measurement mode.
If the buffer is not recognized or the slope is out of accepted range ”--- WRONG” is displayed.
Change the buffer, clean the electrode or press any key to exit calibration.
For better accuracy it is always recommended to carry out a two‑point calibration.
After the calibration procedure has been completed, the tag is turned on together with the
calibrated points.
Exiting calibration and resetting 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 button. The LCD displays “ESC“
for 1 second and the meter returns to normal mode.
To reset the default values and clear a previous calibration, press the SET button after entering the
calibration mode and before the first point is accepted.
The LCD displays “CLEAR“ for 1 second, the meter resets to the default calibration and the
tag with the calibrated points on the LCD disappears.

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OPERATIONAL GUIDE
ELECTRODE CONDITION
The display is provided with a probe icon (unless the feature is disabled from setup) which indicates
the electrode status after calibration. The “condition” remains active for 12 hours (unless the
batteries are removed).
The electrode condition is evaluated only if the current calibration has two points.
5 bars: excellent condition
4 bars: very good condition
3 bars: good condition
2 bars: fair condition
1 bar: poor condition
1 bar blinking: very poor condition
With 1 bar it is recommended to clean the electrode and recalibrate. If there is still only 1 bar or
1 bar blinking replace the probe.
Sensor check
Setting the meter to pH‑mV range the user can check the sensor status at any time. The offset
value is the reading in pH 7.01 buffer (@ 25 °C/77 °F). If this reading is outside the range
±30 mV, the electrode is considered “very poor”. The slope value of the sensor is the difference
between readings in pH 7.01 and in pH 4.01 buffers. When the slope reaches the value of about
150 mV, the electrode is considered “very poor“. When “poor“ or “very poor“, it is recommended
to replace it with a new one.
Note: To ensure reliable readings, the electrode must be cleaned with cleaning solution and
then hydrated in storage solution for a minimum of 30 minutes before calibrating the probe.