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Glossary
GPS
Global Positioning System
GR
Gypsum Requirement (metric ton/ha or ton/
acre).
H
2
T
Tartaric Acid.
HACCP
Hazard Analysis and Critical Control Points.
HC
Handheld Colorimeter.
HF Glass
Hydrofluoric acid can dissolve glass rapidly.
Hanna uses HF resistant glass for aggressive
applications
that
have
fluoride
ions.
Electrodes manufactured with this glass
live ten times longer than electrodes made
with standard pH glass formulations (from
10 days to 100 days). The alkaline error is
very high for this glass so it is not suited
for pH measurements above pH 10. The
recommended pH range with this glass is
2-10 pH.
High Input Impedance Meter
It is the measurement device that processes
the voltage from the electrochemical cell and
converts it into a meaningful measurement
unit (pH). The measurement is done with
virtually zero current flow to prevent
polarization of the electrodes. Modern pH
meters also may provide sensor diagnostics,
automatic buffer recognition, calibration
reminders and user prompts.
HOLD Function
Function that lets the user know when to
take readings and freezes the readings on
display for easy and accurate recording.
HPLC
High Performance Liquid Chromatography.
HR
High Range.
HT Glass
Designed for extended use at elevated
temperature. The glass impedance has a
temperature coefficient of about 14.3%
per degree Celsius. HT sensitive glass has
an impedance of 400 M
Ω
at approximately
25°C (77°F). At extremely high temperatures,
the impedance drops significantly. This
glass makes it possible to obtain accurate,
high temperature pH measurements for
extended periods of time 90°C (194°F) and
for a few weeks at 100°C (212°F). At room
temperature, the response timemay increase
so additional time for equilibration in buffers
should be allowed. This glass is clear.
HVAC
Heating, Ventilating, and Air Conditioning -
refers to technology of indoor or automotive
environmental comfort.
Hygrometer
The hygrometer is an instrument used to
measure relative humidity (RH), that is, the
quantity of water vapor present in the air.
Hygrometers are often available in versions
that also measure temperature—these are
normally called thermohygrometers.
IARC
International Agency for Research on Cancer
iButton® Tags
Install the optional TAGs near your sampling
points for quick and easy iButton® readings.
Each TAG contains a computer chip with
a unique identification code encased in
stainless steel. Users can order and install a
virtually unlimited amount of TAGs to meet
any need of traceability requirements.
ICUMSA
International
Commission
for
Uniform
Methods of Sugar Analysis
17
Glossary
17.11
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