Measuring In Different Media - Unit Conversions; Sulfi Logger Sensors - UNISENSE SULFILOGGER User Manual

been seen from top to bottom of sewer head spaces).
Electrochemical sensors are sensitive to temperature changes,
and for this reason each transducer in the sensor heads is com-
pensated for temperature effects with reference to an internal
temperature measurement in the SulfiLogger™ sensor's sensor
head.
M
EASURING IN DIFFERENT MEDIA
The electrochemical microsensors in the SulfiLogger™ sensor' sen-
sor head measures the partial pressure of H
this can be converted to a ppm-reading if the total barometric
pressure is known, and in the liquid phase the measured value can
be converted to a concentration measured in either µM or mg/L
by using Henry's constant and the molar weight.
Each sensor is ordered with a specification of medium type, and
the signal output from the SulfiLogger™ sensor is chosen as ppm
for gas phase sensor heads and S−mg/L for liquid phase sensor
heads, the "S" in front of mg/L meaning that only the sulfur frac-
tion of the weight is counted in the specified measurement.
The ppm values for gas phase sensors is calculated by using a
standard barometric pressure of 1atm = 101325Pa, and the mg/L
values for liquid phase sensors is calculated by using a tempera-
ture corrected value of Henry's constant. Please note that other
dissolved substances and high salinity values may also influence
the conversion to mg/L units. For more information on this, please
contact Unisense.
S L ™
ULFI OGGER
An overview of the SulfiLogger™ sensor types and their features
can be found in the table below.
SENSORS
17
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UNIT CONVERSIONS
S. In the gas phase,
2