Decagon Devices KD2 Pro Operator's Manual page 19

KD2 Pro 2 KD2 PRO OVERVIEW
Power Mode
You can configure the KD2 Pro to measure each of the three sen-
sor types in either high power mode or low power mode. In high
power mode, the KD2 Pro applies a relatively large heating current
to the sensor during a measurement resulting in greater sensor heat-
ing. In low power mode, the KD2 Pro applies a small current to
the sensor resulting in less heating of the sensor. The KS-1 sensor
defaults to low power mode, while the TR-1, SH-1, and RK-1 needles
all default to high power mode.
We recommend that only expert operators change the power mode
from the default settings for special measurements. In all but a few
cases, changing the power mode from the default settings results in
reduced accuracy.Feel free to contact Decagon to discuss your specific
measurements before changing from the default power mode setting.
Pay attention to the following cautions when operating your KD2
Pro.
Caution: Do not attempt to make measurements in liquids
with the KS-1 or TR-1 in high power mode. The additional
heating from the higher heat input causes free convection
and compromise the measurement.
Caution: Do not attempt to make measurements in fluids
with the SH-1 (dual needle) or RK-1 sensor.
One motivation behind allowing power mode configuration is to allow
the TR-1 and SH-1 sensors to make better measurements in frozen
materials where the decreased heat input in low power mode is less
likely to cause phase change (melting) of the frozen sample. One
situation where we do recommend a non-default power mode setting
is the measurement of thermal conductivity of snow. In this case,
we recommend using the TR-1 needle to reduce issues with contact
resistance, and we recommend configuring the sensor to low power
mode to reduce issues with melting.
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