8
OVERVIEW
This manual covers all the Unisense hydrogen sulfide sensors .
Identify your sensor type before connecting to a picoammeter .
IMPORTANT: The two types of sensors must be polarized
differently . See Polarization section below .
Wrong polarization
may destroy the sensor.
Type I: Label on sensor shaft: SULF-xxx-xxxxxx . The outer glass
casing of the sensor is transparent .
Type II: Label on sensor shaft: H
2
S-xxx-xxxxxx . The outer glass
casing of the sensor is painted black .
The H
2
S microsensors are designed for research applications
within physiology, biotechnology, environmental sciences,
biogeochemistry and related areas .
With their minute tip size, excellent response time, and
minimal stirring sensitivity, the H
2
S sensors makes it possible
to make reliable and fast measurements at high spatial
resolution .
Our H
2
S microsensors are miniaturized amperometric
sensors with internal reference, a sensing and a guard
anode . The sensor is connected to a high-sensitivity
picoammeter and the anodes are polarized against the
internal reference . Driven by the external partial pressure,
H
2
S from the environment enters through the sensor tip
membrane into the electrolyte where the H
2
S is ultimately
oxidised by the anode . This generates a current in the pA
range which is measured by a high quality picoammeter e .g .
the Microsensor Multimeter .
IMPORTANT
Unisense sensors
are neither
intended nor
approved for use of
humans
S
e
n
s
o
r
t
ip
LEMO plug
Cable includes guard
The LEMO connector contains connections for
both reference, guard, and sensing cathode.
