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Glossary
Incremental Method
Incremental Methods are useful techniques
used to determine ion concentration quickly
in samples whose constituents are variable
or
concentrated.
Incremental
Methods
have some inherent advantages over direct
potentiometry. The techniques can reduce
errors from variables such as temperature,
viscosity, pH or ionic strength. The electrodes
remain immersed throughout the process
thus reducing sample carry over and possible
liquid junction changes in the reference and
analysis steps are reduced. Known addition,
known subtraction, analyte addition, and
analyte subtractionmethods are four of these
incremental techniques. All techniques involve
adding a standard to the sample, or sample to
the standard and the meter calculates the
sample’s ion concentration directly.
IR
Infrared. Electromagnetic radiation with a
wavelength longer than VIS (according to CIE
the IR band is 700 nm to 1 mm).
ISA
Ionic Strength Adjusters (ISA) are formulated
to provide a constant ionic strength in
sample and standards alike, thus permitting
concentration
rather
than
activity
measurements to be made. In some cases
ISA’s adjust pH and eliminate matrix effects.
ISE
Ion Selective Electrode, also known as a
specific ion electrode. ISE’s are sensors that
convert the activity of a specific ion dissolved
in a solution into an electrical potential, which
can bemeasured by a pHmeter or a voltmeter.
ISO Standards
See page 18.5
ISOPOTENTIAL pH
Is the pH at which the cell voltage does not
change when the temperature changes.
ISSS
International Society of Soil Science.
ITS
International Temperature Scale.
Junction
The junction (the part in contact between
the two liquids) is typically made with inert
materials that will not increase a junction
potential or be chemically attacked by the
measured solutions.
JTU
Jackson Turbidity Unit.
KEY®
The KEY is a thermometer with an
interchangeable probe for quick spot
measurements. With a response time of less
than 20 seconds in water, KEY is ideal for QC
and industrial temperature monitoring.
KHT
Potassium Bi-Tartrate.
°KMW
°Klosterneuburger Mostwaage is used in
Austria to measure the sugar content of
must. °KMW is also known as °Babo.
°KMW is related to °Oe by the following
equation: °Oe = °KMW x [(0.022 x °KMW) +
4.54]
1 °KMW is roughly equivalent to 1 %Brix or
5 °Oe.
% l.a.
Percent lactic acid is determined by titrating
a 20 mL or 20 g sample diluted with twice its
volume of deionized or distilledwater with 0.1
M sodium hydroxide to a phenolphthalein end
point.
LCD
Liquid Crystal Display.
LDL Cholesterol
Low-density lipoprotein cholesterol.
LED
Light-emitting diode; a semiconductor light
source.
LI
Langelier Index is a saturation index
developed by Dr. Wilfred Langelier and
is widely used to predict the balance of
swimming pool waters. It is an estimation of
the solutions ability to dissolve or precipitate
calcium carbonate deposits.
17
Glossary
17.12
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