Hanna Instruments HI 99121 User manual

SPECIFICATIONS
Instruction Manual
HI 99121
Soil pH Test Kit
www.hannainst.com

32
PRELIMINARY EXAMINATION
Remove the test kit from the packing material and examine it
carefully to make sure that no damage has occurred during
shipping. If there is any damage, immediately notify your dealer.
Each kit includes:
•HI 99121 portable pH meter
•HI 1292D pH electrode
• pH 4.01 & pH 7.01 buffer solutions (20 mL each)
•HI 700663 cleaning solution for inorganic soil deposits
•HI 700664 cleaning solution for organic soil deposits
•HI 7051M soil preparation solution
•HI 721319 ground auger
• 3 x 1.5V AA alkaline batteries
• instruction manual
• rugged carrying case
Note: Save all packing material until you are sure that the
instrument functions correctly. All defective items must
be returned in the original packing with the supplied
accessories.
Dear Customer,
Thank you for choosing a HANNA instruments®product.
Please read this instruction manual carefully before using the
instrument. This manual will provide you with the necessary
information for correct use of the instrument, as well as a more
precise idea of its versatility.
If you need additional technical information, do not hesitate to e-
mail us at [email protected].
This instrument is in compliance with the directives.
WARRANTY
All Hanna Instruments meters are warranted for two years against
defects in workmanship and materials when used for their intended
purpose and maintained according to instructions. The probes are
warranted for a period of six months.
This warranty is limited to repair or replacement free of charge.
Damage due to accidents, misuse, tampering or lack of prescribed
maintenance are not covered.
If service is required, contact the dealer from whom you purchased
the instrument. If under warranty, report the model number, date of
purchase, serial number and the nature of the problem.
First obtain a Returned Goods Authorization number from the Cus-
tomer Service department, then return the instrument with the
Authorization number included along with shipment costs prepaid.
If the repair is not covered by the warranty, you will be notified of
the charges. When shipping any instrument, make sure it is properly
packaged for complete protection.
TABLE OF CONTENTS
PRELIMINARY EXAMINATION ........................................... 3
WARRANTY ......................................................................... 3
SOIL pH ............................................................................... 4
ORGANIC SUBSTRATE ...................................................... 8
IRRIGATION WATER ........................................................... 8
NUTRIENT SOLUTION........................................................ 8
pH METER SPECIFICATIONS...........................................11
OPERATING THE pH METER ...........................................12
pH MEASUREMENT & CALIBRATION ..............................13
METER SETUP...................................................................14
ELECTRODE CLEANING ...................................................15
BATTERY REPLACEMENT................................................15

54
pH is the measure of the hydrogen ion concentration [H+]. Soil
can be acid, neutral or alkaline, according to its pH value.
Fig. 1 shows the relationship between the scale of pH and
types of soil. Most plants prefer a pH range from 5.5 to 7.5;
but some species prefer more acid or alkaline soils.
Nevertheless, every plant requires a particular range of pH,
for optimum growth.
pHstronglyinfluencestheavailabilityofnutrientsandthepresence
of microorganisms and plants in the soil.
For example, fungi prefer acidic conditions whereas most
bacteria, especially those supplying nutrients to the plants,
have a preference for moderately acidic or slightly alkaline
soils. In fact, in strongly acidic conditions, nitrogen fixing and
the mineralization of vegetable residual is reduced.
Plants absorb the nutrients dissolved in the soil water and the
nutrient solubility depends largely on the pH value. Hence, the
availability of elements is different at different pH levels (Fig.2).
SOIL pH Each plant needs elements in different quantities and this is the
reason why each plant requires a particular range of pH to
optimize its growth.
For example, iron, copper and manganese are not soluble in
an alkaline environment. This means that plants needing these
elements should theoretically be in an acidic type of soil.
Nitrogen, phosphorus, potassium and sulfur, on the other
hand, are readily available in a pH range close to neutrality.
Furthermore, abnormal pH values, increase the concentration
of toxic elements for plants. For example, in acid conditions,
there can be an excess of aluminum ions in such quantities
that the plant can not tolerate.
Negative effects on chemical and physical structure are also
present when pH values are too far from neutral conditions
(break up of aggregates, a less permeable and more compact
soil).
Management of the soil in relation to the pH value
Once the pH value is known, it is advisable to choose crops
that are suitable for this range (e.g. in an acid soil, cultivate
rice, potato, strawberry).
Add fertilizers that do not increase acidity (for example urea,
calcium nitrate, ammonium nitrate and superphosphate) or
lower alkalinity (e.g. ammonium sulfate).
It is recommended that a cost evaluation is made prior to
commencement of the soil pH modification. Corrective
substances can be added to modify the soil pH, however, the
effects are generally slow and not persistent. For example, by
adding lime, the effects in clay soil can last for as long as 10
years, but only 2-3 years in a sandy soil.
For an acid soil, we can use substances such as lime, dolomitic,
limestone and marl, according to the nature of the soil (Tab.1).
Soil Ameliorants Clay soil Silty soil Sandy soil
CaO 30-50 20-30 10-20
Ca(OH)239-66 26-39 13-26
CaMg(CO3)249-82 33-49 16-33
Ca CO354-90 36-54 18-36
Tab.1. Quantity (q/ha) of pure compound necessary to in-
crease 1 unit of pH
Fig. 1. Types of soil according to the pH value
Fig. 2. Solubility of the elements according to varying pH

76
High pH levels can depend on different elements, hence, there
are different methods for its correction.
- Soils rich with limestone:
Add organic matter (this is due to the fact that non-organic
ameliorants such as sulfur and sulfuric acid might not make
economic sense due to the large quantities needed).
- Alkaline-saline soils:
Alkalinity is due to the presence of salts (in particular a high
concentration of sodium can be harmful).
Irrigation washes away salts, hence, an appropriate use of
irrigation can provide positive results (drop-irrigation being the
most recommended).
If alkalinity is caused by sodium, it is recommended to add
substances such as gypsum (calcium sulfate), sulfur or other
sulfuric compounds (Tab.2). Also in this case, a cost evaluation
is necessary.
Soil ameliorants (pure compounds) Quantity (kg)
Calcium chloride: CaCl2· 2H2O85
Sulfuric acid: H2SO457
Sulfur: S 19
Iron sulfate: Fe2 (SO4)3 · 7H2O 162
Aluminum sulfate: Al2 (SO4)3129
Tab.2. Quantities provide the same result as 100 kg of gypsum
Procedure for direct ground measurement
1) Dig, discarding 5 cm of topsoil
2) Perforate the soil (with HI 721319 soil drill) to a depth of
about 20 cm or more
3) If the soil is dry, moisten it with a small amount of distilled
water
4) Wash the electrode with tap water (not distilled)
5) Insert the electrode pushing it slightly into the soil to ensure
proper contact
6) Observe the measurement
7) Wash the electrode with tap water (not distilled) and (using
a finger) gently remove any soil remaining on the electrode
(avoid using a rag or cloth)
8) Repeat the procedure in different locations in the field
9) Consider the average of the measured data
Forbest result, it is advisabletomeasurethepH of a soil solution,
using a sample of soil and soil preparation solution HI 7051; it is
better to use this procedure if you have to test a stony field in
which you risk damaging the electrode.
Procedure for the measurement of soil solution (1:2,5)
A) Sampling
1) Extracting Soil Sample.
Take 1 sample per 1000 m2(0.25 acre) of homogeneous
area.
Even for small areas, 2 samples are recommended (the
more the samples, the better the end-results, because the
result is more representative).
2) Avoid extracting samples from soil presenting obvious
anomalies and consider them separately.
3) Sample quantity:
Take the same quantity of soil for each sample. For example,
use bags with similar dimensions (1 bag per sample).
4) Depth of extraction:
General: dig and discard 5 cm (2") of topsoil.
Herbaceous crops: from 20 to 40 cm of depth (8" to 16").
Orchards: from 20 to 60 cm of depth (8" to 24'’).
5) Spread the soil samples on the pages of a newspaper and
let the soil dry in a shady place or put it in an oven at 40°C.
6) Crumble the dried soil and mix all the samples together to
obtain a homogeneous mixture, discarding stones and
vegetable residues.
7) From this mixture, take the soil sample for analysis.
B) Soil solution preparation and measurement
1) Sift the soil at 2 mm.
2) Weigh 10 g of soil and put it in 25 ml of soil preparation
solution HI 7051 (use the apposite beaker) or 20 g of soil per
50 ml of soil preparation solution HI 7051.
3) Mix for 30 seconds.
4) Wait for about 5 minutes.
5) Mix again and measure the pH of the solution.

98
ORGANIC SUBSTRATE
pH measurements of organic substrates is important in
greenhouses and nursery growing pots. pH should be checked
at the outset to make sure that the pH of the substrate bought
is that desired (pH can change if too much time elapses from
the date of packaging to the moment of utilization).
A) Direct measurement in pot
If the substrate is dry, add a little distilled water. Insert the
electrode into the soil and take measurement.
B) Measurement of the organic substrate solution (1:2)
Let the substrate dry and discard the coarse vegetable residues
and pebbles.
Prepare a solution composed of 1 part of mould and 2 parts
of HI 7051 solution (for example: fill the beaker with the
substrate up to 50 ml, press it gently, empty the content in
another container and add 100 ml of HI 7051 solution).
Mix for 30 seconds and then wait for 5 minutes. Mix again and
measure the pH of the solution.
NUTRIENT SOLUTION
A rational fertilization is needed for optimum plants growth in
greenhouses. The pH value of the nutrient solution (water +
fertilizer) has to meet the plants need.
If a fertirrigation system with automatic pH control is used,
ensure that it is functioning properly.
Check the pH of the irrigation solution as well as any recycled
solution.
IRRIGATION WATER
The quality of irrigation water is a very important factor. If the
pH value is very far from pH 7, it is possible that other
anomalies are present.
Ranges for evaluation of water quality:
- 6 to 8.5 pH: good, it can be utilized without problems.
- 5 to 6 pH or 8.5 to 9 pH: sufficient, sensible crops could
have problems.
- 4 to 5 pH or 9 to 10 pH: scarce, use it carefully, avoid
wetting the vegetation.
- pH<4 or pH>10: very scarce, there are other anomalies that
have to be identified via chemical analysis.
ORCHARD PLANTS
Preferred pH Range Preferred pH Range
Apple 5-6.5 Orange 5-7
Apricot 6-7 Peach 6-7.5
Cherry 6-7.5 Pear 6-7.5
Grapefruit 6-7.5 Plum 6-7.5
Grapevine 6-7 Pomegranate 5.5-6.5
Lemon 6-7 Walnut 6-8
Nectarine 6-7.5
VEGETABLES AND HERBACEOUS CULTIVATIONS
Preferred pH Range Preferred pH Range
Artichoke 6.5-7.5 Pepper 6-7
Asparagus 6-8 Early Potato 4.5-6
Barley 6-7 Late Potato 4.5-6
Bean 6-7.5 Sweet Potato 5.5-6
Brussels Sprout 6-7.5 Pumpkin 5.5-7.5
Early carrot 5.5-7 Rice 5-6.5
Late carrot 5.5-7 Soybean 5.5-6.5
Cucumber 5.5-7.5 Spinach 6-7.5
Egg Plant 5.5-7 Strawberry 5-7.5
Lettuce 6-7 String 6-7.5
Maize 6-7.5 Sugar beet 6-7
Melon 5.5-6.5 Sunflower 6-7.5
Oat 6-7 Tomato 5.5-6.5
Onion 6-7 Watermelon 5.5-6.5
Pea 6-7.5 Wheat 6-7
LAWN
Preferred pH Range
Lawn 6-7.5
GARDEN PLANTS AND FLOWERS
Preferred pH Range Preferred pH Range
Acacia 6-8 Ligustrum 5-7.5
Acanthus 6-7 Magnolia 5-6
Amaranth 6-6.5 Narcissus 6-8,5
Bougainvillea 5.5-7.5 Oleander 6-7.5
Dahlia 6-7.5 Paulownia 6-8
Erica 4.5-6 Portulaca 5.5-7.5
Euphorbia 6-7 Primula 6-7.5
Fuchsia 5.5-7.5 Rhododendron 4.5-6
Gentian 5-7.5 Roses 5.5-7
Gladiolus 6-7 Sedum 6-7.5
Hellebore 6-7.5 Sunflower 5-7
Hyacinth 6.5-7.5 Tulip 6-7
Iris 5-6.5 Viola 5.5-6.5
Juniper 5-6.5

1110
HOUSE PLANTS
Preferred pH Range Preferred pH Range
Abutilon 5.5-6.5 Gardenia 5-6
African violet 6-7 Geranium 6-8
Anthurium 5-6 Hibiscus 6-8
Araucaria 5-6 Jasmine 5.5-7
Azalea 4.5-6 Kalanchoe 6-7.5
Begonia 5.5-7.5 Mimosa 5-7
Camellia 4.5-5.5 Orchid 4.5-5.5
Croton 5-6 Palms 6-7.5
Cyclamen 6-7 Peperomia 5-6
Dieffenbachia 5-6 Philodendron 5-6
Dracaena 5-6 Yucca 6-7.5
Freesia 6-7.5
Range (*) -2.00to 16.00pH
-5.0to105.0°C/23.0to221.0°F
Resolution 0.01 pH / 0.1°C / 0.1°F
Accuracy ±0.02pH
(@20°C/68°F) ±0.5°Cupto60°C;±1°Coutside
±1°Fupto140°F;±2°Foutside
Temperature Compensation Automatic
pH Calibration Automatic,1or2point
with2setsofmemorizedbuffers
Probe (included) HI1292DpH/temperatureprobe
Battery Type / Life 3x1.5VAA(IECLR6)/ approx.1500hours
Auto-off After8minutesofnon-use
Environment 0 to 50°C (32 to 122°F); RH 100%
Dimensions 150x80x36mm(5.9x 3.2 x 1.4”)
Weight 210g(7.4 oz.)
(*) The temperature range is limited to 80°C (176°F) if using the
HI1292D probe.
To clean the meter, use water only.
pH METER SPECIFICATIONS

1312
To connect the probe
Withthemeterturnedoff,connecttheHI 1292DprobetotheDIN
socketonthetopofthemeterbyaligningthepinsandpushingin
theplug.Tightenthenuttoensureagoodconnection.Remove
the protective cap from the probe before taking any measure-
ments.
To turn the meter ON and check the battery status
Press the ON/OFF/MODE button until the display lights up.At
start-up,alltheLCDsegmentsaredisplayedfor1second,then
the percent indication of the remaining battery life is shown for
anothersecond (E.g. % 100BATT).Themeterthen enters the
normal measuring mode.
Note: If the display needs to be checked, keep the ON button
pressedwhileturningthemeteron.Themeterwilldisplayall
segments as long as the button is pressed.
To freeze the display
While in measurement mode, press the SET/HOLD button,
HOLD appears on the secondary display and the reading will
be frozen on the LCD (E.g. pH 5.73 HOLD). Press any button
to return to normal mode.
To turn the meter OFF
Whileinnormalmeasurementmode,presstheON/OFF/MODE
button.OFF will appear on the secondarydisplay.Releasethe
button.
Note:Themeterisprovidedwithanacousticsignalfeature,which
canbedisabledusingtheswitchlocatedinthebatterycom-
partment.
Note:Whenthemeterdetectstheabsenceofatemperatureprobe
atitsinput,theAutomaticTemperatureCompensationisturned
off,andthemeterusesadefaultvalueof25°C(77°F)forthe
temperaturemeasurementandcompensation.Inthiscondi-
tion,thesecondaryLCDshows25.0°C(77.0°F)blinking.
Whenaprobeisconnected,themeterautomaticallyreturns
totheATCmode,theATCtagisturnedon,andthetempera-
tureisshownonthesecondarydisplay.
• Makesurethemeterhasbeencalibratedbeforeuse.
• If the probe is dry, soak it in HI 70300 storage solution for
one hour to reactivate it.
• Placethetipoftheprobeintothesampletobetested,stirbriefly
andwaituntilthestabilitysymbolontheLCDisturnedoff.
• TheLCDshowsthepHvalue(automaticallycompensatedfor
temperature) on the primary LCD, while the secondary LCD
showsthetemperatureofthesolution.
• Ifmeasurementsaretakenindifferentsamplessuccessively,rinse
theprobetipthoroughlytoavoidcontaminations.Aftercleaning,
rinsetheprobetipwithsomeofthesampletobemeasured.
pH calibration
For better accuracy, a frequent electrode cleaning (see
also pag. 15) and meter calibration 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.
• Fromnormalmode,press&holdON/OFF/MODEuntilOFFon
thesecondarydisplayisreplacedbyCAL.Releasethebutton.
• TheLCDentersthecalibrationmode,displaying“pH7.01USE”
(or“pH6.86USE”iftheNISTbuffersetwasselected).After1
secondthemeteractivatestheautomaticbufferrecognitionfea-
ture.Ifavalidbufferisdetected,thenitsvalueisshownonthe
primary display, and REC appears on the secondary LCD. If
novalidbufferisdetected,themeterkeepstheUSEindication
activefor12seconds,andthenreplacesitwithWRNG,indicat-
ingthatthesamplebeingmeasuredisnotavalidbuffer.
• For a single-point calibration with buffers pH 4.01, 9.18 or
10.01,themeterautomaticallyacceptsthecalibrationwhenthe
readingisstable;themeterwillshowontheprimarydisplaythe
accepted buffer, with the message “OK 1” on the secondary
display,andanaudiblesignalisproduced.After1secondthe
meterautomaticallyreturnstothenormalmeasuringmode.
Ifasingle-pointcalibrationwithbufferspH7.01or6.86isde-
sired,thenafterthecalibrationpointhasbeenacceptedpress
the ON/OFF/MODE button in order to return to the normal
measuringmode.Afterthebuttonispressed,themetershows
OPERATING THE pH METER pH MEASUREMENT & CALIBRATION

1514
"7.01"(or"6.86")-"OK1",andanaudiblesignalisproduced.
After1second,themeterautomaticallyreturnstothenormal
measuringmode.
Note:Itisalwaysrecommendedtocarryoutatwo-pointcalibra-
tionforbetteraccuracy.
• Foratwo-pointcalibration,placetheprobeinpH7.01(orpH
6.86) buffer. After the calibration point has been accepted,
the “pH 4.01 USE” message appears. The message is held
for12seconds,unlessavalidbufferisrecognized.Ifnovalid
bufferisrecognized,thentheWRNG messageisshown. Ifa
validbuffer(pH4.01, pH10.01 orpH9.18)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 on the secondary display. The meter
then returns to the normal measuring mode.
Note:Whenthecalibrationiscompleted,theCALtagisturnedon.
To quit calibration and to reset to the default values
• Afterenteringthecalibrationmodeandbeforethefirstpointisac-
cepted,itispossible to quit the procedure and return to the last
calibrationdatabypressingON/OFF/MODE.ThesecondaryLCD
displaysESCfor1sec.andthemeterreturnstonormalmode.
• Toresettothedefaultvaluesandclearapreviouscalibration,
presstheSET/HOLDbuttonafterenteringthecalibrationmode
andbeforethefirstpointisaccepted.
ThesecondaryLCDdisplaysCLRfor1sec,themeterresetstothe
defaultcalibrationandthe“CAL”tagontheLCDdisappears.
SetupmodeallowstoselectthetemperatureunitandthepHbuffer
set.ToentertheSetupmode,press&holdON/OFF/MODEuntil
CAL on the secondary display is replaced by TEMP and the
currenttemperatureunit(E.g.TEMP°C).Then:
•for°C/°Fselection,usetheSET/HOLDbutton.Afterthetem-
perature unit has been selected, press ON/OFF/MODE to
enter the buffer set selection mode; press ON/OFF/MODE
twice to return to the normal measuring mode.
•tochangethecalibrationbufferset,aftersettingthetempera-
tureunit,themeter will show the current buffer set: “pH 7.01
BUFF” (for 4.01/7.01/10.01) or “pH 6.86 BUFF” (for 4.01/
6.86/9.18). Change the set with the SET/HOLD button, then
press ON/OFF/MODE to return to normal mode.
The meter displays the remaining battery percentage when
turned on. When the level is below 5%, the
- +
symbol on the
bottomleft of the LCD blinks toindicatealowbattery condition.
If the battery level is low enough to cause erroneous readings,
theBatteryErrorPreventionSystem(BEPS)turnsthemeteroff.
Unscrew the 4 screws located on the back of the meter and
carefully replace the 3 AA batteries located in the battery com-
partment, while paying attention to their polarity. Reattach the
back making sure that the gasket is in place and tighten the 4
screws to ensure a watertight seal.
METER SETUP BATTERY REPLACEMENT
ELECTRODE CLEANING
AfrequentcleaningofthepHelectrodeisstronglyrecommendedto
ensurecorrectcalibrationandreliablereadings.
HannaInstrumentshasdevelopedacompleteseriesofcleaning
solutionsdedicatedtospecificapplicationsandkindofdirtythathas
toberemovedfromtheelectrode.
Insoilmeasurementsyoucanchoosebetweentwodifferentsolu-
tionsaccordinglytothetypeoftestedsoil:
•HI700663 isindicatedfor inorganicsoildeposits(asminerals,
limestone,adsorbedclays)
•HI700664isspecificfororganicsoildeposits(humus)
Ifcleaningisperformedfrequently,soaktheelectrodeinthespecific
solutionforafewminutes.
If the electrode has not be cleaned for a while, for a complete
removalofsoildeposits,proceedasfollows:
•wipetheelectrodebody(notbulb)withpaperorsofttissue
•rubthereferencewithabrasivepaper
•immerseintocleaningsolutionforatleast15minutes.

MAN99121R3 09/05
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