Hanna Instruments hi 38074 User Manual

Instruction Manual

HI 38074

Boron

Test Kit for

Irrigation Water

www.hannainst.com

Dear Customer,

Thank you for choosing a Hanna Product.

Please read the instruction sheet carefully before using the

test kit. It will provide you with the necessary information

for correct use of the kit. If you need additional information,

do not hesitate to e-mail us at tech@hannainst.com.

Remove the chemical test kit from the packing material and

examine it carefully to make sure that no damage has

occurred during shipping. If there is any noticeable dam-

age, notify your Dealer or the nearest Hanna office

immediately.

Each kit is supplied with:

• HI 38074A-0 Boron Reagent, 1 bottle with dropper

(30 mL);

• HI 38074B-0 Boron Reagent, 1 bottle with dropper

(30 mL);

• HI 38074C-0 Boron Reagent, 1 bottle (100 mL);

• Mannitol, powder in packets (100 pcs);

• HI 38074E-0 Boron Reagent, 1 bottle (100 mL);

• HI 70004, 1 sachet;

• HI 70007, 1 sachet;

• 1 Checker , pocket-sized pH-meter;

• 1 screwdriver;

• 1 empty bottle (120 mL) with cap;

• 1 calibrated plastic vessel (50 mL);

• 2 plastic pipettes (1 mL).

Note: Any damaged or defective item must be returned in

its original packing materials.

ISTR38074

10/00

PRINTED

ITALY

Boron is one of the micronutrients essential for plant growth. It

may be present naturally in water or may find its way into a

watercourse through industrial waste effluents. Boron in excess

of 2.0 mg/L in irrigation water is detrimental to many plants,

but some plants may even be affected adversely by concentra-

tions lower than 1.0 mg/L.

The US Department of Agriculture reports the following classifi-

cation:
ppm of Boron

effect on crops

<0.5

good (except for very sensitive

crops)

0.5-2.0

some risks (many crops must

be excluded)

>2.0

dangerous (may only be used

for very tolerant crops)

Note: mg/L is equivalent to ppm (parts per million).

SPECIFICATIONS

SIGNIFICANCE AND USE

CHEMICAL REACTION

INSTRUCTIONS

The Hanna Test Kit allows the determination of boron

concentration in irrigation waters by direct titration of boric

acid.

READ THE ENTIRE INSTRUCTIONS BEFORE USING THE KIT

• Calibrate the pH electrode following the instructions in

the Checker instrument manual.

Range

0 to 5 mg/L (ppm) as Boron

Smallest Increment

0.2 ppm Boron

Analysis Method

Titration

Sample Size

50 mL

Number of Tests

100

Case Dimensions

235x175x115 mm (9.2x6.9x4.5")

Shipping Weight

780 g (27.5 oz.)

• Fill the plastic vessel with 50 mL of

sample (up to the mark).

• Add 3 drops of HI 38074A-0 Boron Reagent and swirl

to mix.

• Insert the Checker pH electrode into the

vessel and measure the pH. The pH must be

lower than 7. If pH is higher than 7, add

HI 38074B-0 reagent drop by drop, swirl-

ing after each drop, until pH becomes lower

than 7.

• Using one of the plastic pipettes, add drops of HI 38074C-0

Boron Reagent, swirling after each drop.

• Keep on adding HI 38074C-0 reagent until the pH

reaches the 7.8±0.2 value. Write down the exact pH

value and report it as pH

start

(e.g.: pH

start

=7.85).

Note 1: If pH stabilizes at a value higher than 8, too

many drops of HI 38074C-0 reagent have been

added. In this case, add 1 drop of HI 38074B-0

reagent and swirl, then add again drops of

HI 38074C-0 to adjust the pH to 7.8±0.2.

Note 2: If carbonates are present, the pH readings will

show a drift after each addition. Wait until the pH

stabilizes before adding the next drop of HI 38074C-0

reagent.

• Add 1 packet of Mannitol reagent and swirl gently to

dissolve.

• Measure the pH:

If pH is lower than pH

start

(e.g.: pH=7.52), use

the other plastic pipette to add HI 38074E-0 Boron

Reagent drop by drop, swirling after each drop, while

keeping an accurate count of the number of drops being

added to the solution. Keep adding the reagent until

pH becomes equal or higher than pH

start

(7.85). Use the

Boron Conversion Table below to convert the number of

drops added in mg/L (or ppm) of Boron (e.g.: 10 drops

of HI 38074E-0 reagent correspond to 2.0 mg/L of

Boron).

If pH does not change after addition of the

powder packet, boron is absent. As a confirmation, add

one drop of HI 38074E-0 reagent and pH will immedi-

ately increase a lot.

x 3

50 mL

BORON CONVERSION TABLE

number

mg/L

number

mg/L

of drops

Boron

of drops

Boron

0.2

2.8

0.4

3.0

0.6

3.2

0.8

3.4

1.0

3.6

1.2

3.8

1.4

4.0

1.6

4.2

1.8

4.4

2.0

4.6

2.2

4.8

2.4

5.0

2.6

5.2