transformed into orthogonal coordinates. Because of this correction, it is not necessary to apply
the speed of sound correction described by Liu, Peter, and Foken (2001; see
The CSAT3BH has several operating modes to suit different applications. The anemometer can
be configured to make a single measurement per data logger trigger, or it can operate in a self-
triggered mode. When self-triggering, the CSAT3BH will make measurements at a high rate,
apply an optional user-selectable bandwidth filter, and provide the latest output upon receiving
an output prompt. An output prompt may come from the data logger, or in the case of
unprompted output mode (such as computer data collection), the output is prompted by the
CSAT3BH itself. The default operating mode of the CSAT3BH is to make measurements when
triggered by a data logger (SDM or CPI), which does not apply any low-pass (high-cut) filtering.
See
(p. 44) for a list of all default settings, and see
(p. 65) for
more information on modes.
5.1 Measurements
Operating temperature
Standard:
–40 to 50 °C
Wind accuracy (–40 to 50 °C, wind speed < 30 m·s
–1
, azimuth angles between ± 170 °C)
Offset error
u
x
:
± 8 cm·s
–1
max
u
y
:
± 8 cm·s
–1
max
u
z
:
± 4 cm·s
–1
max
Gain error
Wind vector ± 5° of horizontal:
± 2% of reading max
Wind vector ± 10° of horizontal:
± 3% of reading max
Wind vector ± 20° of horizontal:
± 6% of reading max
Wind resolution
u
x
:
1.0 mm·s
–1
RMS
u
y
:
1.0 mm·s
–1
RMS
u
z
:
0.5 mm·s
–1
RMS
Wind full scale range:
± 65 m·s
–1
Sonic temperature resolution:
± 0.002 °C RMS at 25 °C
CSAT3BH Three-Dimensional Heated Sonic Anemometer
18
