15
MEASUREMENTS
Nitrous oxide sensors can be used for a wide variety of
measurements (please see our web page
www.unisense.com
for further information). They are for
example used for making profiles in sediments or tissues
where a high spatial resolution is required or for nitrous oxide
measurements in water samples.
M
OUNTING
THE
SENSORS
Although the Unisense microsensors are made of glass,
the tip is flexible and can adjust slightly around physical
obstacles. The sensor is thus rather sturdy in the longitudinal
direction. However, large obstacles like stones or lateral
movements of the sensor when the tip is in contact with a
solid substrate may cause the tip to break.
Furthermore, due to the small size of the microsensor tip
and to the steepness of gradients in many environments, a
displacement of the sensor tip of only a few microns may
change its environment.
Therefore, when working with glass-tip microsensors, we
recommend that measurements are performed only in a stable
set-up free of moving or vibrating devices. We recommend the
Unisense laboratory stand LS and the Unisense micro-
manipulator MM33 (double MM33-2) for laboratory use. For in situ
use we recommend our in situ stand (IS19) and a micromanipulator.
E
LECTRICAL
NOISE
The signal of the microsensor is in the 10
-13
to 10
-10
ampere range.
Although both the Unisense picoammeter and the Unisense nitrous
oxide microsensors are quite resistant to electrical noise from the
environment, electrical fields may interfere with the sensor signal.
Therefore, we recommend that unnecessary electrical/mechanical
equipment is switched off and the sensor or wires are not touched
TEMPERATURE
Closely monitor
the temperature.
The temperature
coefficient varies
from sensor to
sensor but is
approximately
2-3% per
o
C.
UniAmp instru-
ments has
automatic
temperature
compensation
within ±3°C from
the calibration
temperature, if
a temperature
sensor is
connected.
