User Guide

EXCESS EFFECTS • reduced absorption of calcium and magnesium
• increase of water consumption
• increase of the substrate salinity
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MAGNESIUMMAGNESIUM
MAGNESIUMMAGNESIUM
MAGNESIUM
Magnesium (Mg) is essential for the formation of chlorophyll and it
stimulates the absorption of phosphorus by plants.
PRESENT IN
chlorophyll
ACTION • it acts similar like calcium
• is present in chlorophyll and pectin
• it stimulates absorption of phosphourus
SHORTAGE • interveinal chlorosis which first develops in older
EFFECTS leaves
• small veins and not green
• severe starvation, older leaves shrivel and die
EXCESS EFFECTS • very little information available on visual symptoms
CALCIUMCALCIUM
CALCIUMCALCIUM
CALCIUM
Calcium (Ca) forms a structural part of the plant cell walls. It helps to
build up resistance against fungus and bacteriological attack.
PRESENT IN
tissue of cell walls
ACTION • it gives rigidity or stiffness to plant stems
• it stimulates roots growth
• neutralizes organic acids like oxalic and succinic acid
• regulates the absorption of potassium, magnesium
etc.
SHORTAGE • young leafs become distorted
EFFECTS • bud development is inhibited
• root tips often die
• plant growth stunted with short internodes
EXCESS EFFECTS • no consistent visual symptoms, usually associated
with excess carbonates
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SPECIFICATIONS
Range 0.0 to 20.0 mg/L
Resolution 0.5 mg/L
Accuracy ±3.0 mg/L ±7% of reading
Light Source Tungsten lamp with narrow band interference
filter @ 610 nm
Method Adaptation of the Turbidimetric Tetraphenylborate
method. The reaction between potassium and
reagents causes turbidity in the sample.
REQUIRED REAGENTS
Code Description Quantity
HI 93750
AA
AA
A-0 Potassium Reagent 6 drops
HI 93750
BB
BB
B-0 Powder Reagent 1 packet
REAGENT SETS
HI 93750-01 Reagents for 100 tests
HI 93750-03 Reagents for 300 tests
For other accessories see page 56.
MEASUREMENT PROCEDURE
Note: for sample preparation follow the IRRIGATION WATER (LR)
procedure at page 19.
• Select the program number 10 “Potassium LR” on the secondary
LCD by pressing PROGRAM M and L.
• Fill the cuvet with 10 mL of sample, up to the
mark.
• Add six drops of HI 93750A,
replace the cap and swirl the
solution.
• Place the cuvet into the holder and
ensure that the notch on the cap is
positioned securely into the groove.
10 mL
x 6
Potassium LR
POTASSIUM LOW RANGE