809 / 836
SAR
Sodium Absorbtion Ratio (meq/L).
Sensor Check™
Allows users to check electrode status at any
time.
°SH
Soxlet Henkel degrees is determined by
titrating a 50 mL sample with 0.1 M sodium
hydroxide to a phenolphthalein end point.
SHE
Standard Hydrogen Electrode.
SMART electrode
WithmodelsthatfeatureourSMARTcircuitry,
an exclusive microchip embedded inside the
electrode retains the calibration data and
assigns an identity code to the host unit. As
soon as the electrode is connected to a pH
meter in the SMART series, it is recognized
and its characteristics retrieved. The meter
then uses the accessed calibration data
as a reference for future measurements.
Once each SMART electrode is calibrated,
these electrodes can be used in succession
without requiring new calibration. Hanna’s
intelligent electrodes help eliminate errors
and will save time when working with more
than one electrode.
SOP
Standard
Operating
Procedures
means
documented procedures which describe
how to perform tests or activities normally
not specified in detail in study plans or
tests guidelines.
SOUR
Specific Oxygen Uptake Rate. This is used
to determine the oxygen consumption or
respiration rate; SOUR is measured in mg
of oxygen consumed per gram of volatile
suspended solids per hour.
SPDT relay
Single Pole Double Throw relay.
Specificity
Specificity
is
the
ability
to
assess
unequivocally the analyte in the presence
of components which may be expected to
be present. Typically these might include
impurities, degradants, matrix, etc.
Speedsafe™
Each Hanna stirrer is equipped with a speed
sensing device (opto-sensor) coupled with
an FVC (frequency voltage converter), which
monitors the speed. As the speed reaches a
presetmaximum level, the speed limiter shuts
down the VCO to slow down the motor speed.
This ensures that when the load is suddenly
removed from the stirrer, the motor will not
accelerate to such a high speed that will be
hazardous to both the user and the stirrer; a
feature not commonly found in conventional
stirrers.
SPST Relay
Single Pole Single Throw relay.
SRM
Standard ReferenceMaterial (CRMof National
Institute of Standards and Technology).
Storage Solution
Solution used to keep the electrode moist
when not in use.
TDS
Total Dissolved Solids (often abbreviated
TDS) is a measure of the combined content
of all inorganic and organic substances
contained in a liquid in: molecular, ionized or
micro-granular (colloidal sol) suspended form.
TDS Factor
When a solution does not have a similar
ionic content to natural water or salt water,
then a TDS conversion factor is needed to
automatically adjust the readings. TDS = CF
x conductivity (CF is TDS Conversion factor).
TFPC
Thin Film Polymer Capacitance.
Glossary
17
Glossary
17.17
www.hannainst.com|