Campbell Scientific CS725 Snow Water Equivalency Sensor User Manual
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CS725 Snow Water Equivalency Sensor
[16] SN Threshold for the snow cover
This parameter is a threshold above which the normal calculation of
the SWE will be performed. The threshold is applied to a calculation
of the SWE based on the ratio of K/Tl, which is independent of the
humidity of the soil, but less accurate than the SWE measured from
the K and Tl information independently. When the SWE calculated
from the K/Tl ratio is reached, it is assumed that there is a snow
cover. The nominal humidity parameter is then used for the
calculation. Otherwise, the snow cover is assumed to be zero, and the
CS725 calculates the humidity of the soil. The default value is 5 mm.
[17] Baud rate for scheduled transmissions
This parameter defines the baud rate to be used for the automatic data
transmissions. In interactive mode with a terminal, the CS725 can
adjust to the terminal’s baud rate by typing capital UU period then
enter “UU.
CS725 will use the baud rate specified by this parameter. This is for
the cases when an interactive terminal used for the configuration of a
site is disconnected and replaced by the normal communication
device (modem, satellite, datalogger) with a different baud rate. This
guarantees that the scheduled transmissions will be done at the proper
baud rate for the communication device. The default rate is 9600 bps.
Valid values for this parameter are: 1200, 2400, 4800, 9600, 19200,
38400, 57600, and 115200.
[18] Number of hours per partial histo (hours),(1,2,3,or 6)
It is highly recommended to leave this setting to 1 hour. It is
recommended to contact Campbell Scientific technical support prior
to using other values.
In normal operation, 1-hour histograms generate 24 partial histograms
per day. However, under very large snow packs (more than 500 mm),
the absorption of the gamma rays is such that the peaks do not stand
up much above the cosmic radiation background after one hour of
counting. In this case, the peak identifying mechanism may fail. To
overcome this situation, it is possible to have histograms generated in
periods of 2,3, or 6 hours.
[19] Manual mode (1); Auto mode (0) ; HCalib mode (2);
This parameter defines the operating mode of the CS725. In the
manual mode (code =1), the CS725 will accumulate a histogram from
the initialization cycle until it a manual command is sent to delete it.
No calculations of SWE will be performed, and no results
transmission will be scheduled. This mode is used normally when
setting up the CS725 (i.e., verifying the peak positions, modifying
parameters, setting the time, etc.).
The HCalib mode (code = 2) has been referred to in the parameter
description for [10] HCalib. When this mode is set, the CS725 will
acquire the data in a normal manner, and the results will be
transmitted at the end of the period at the scheduled transmission
time. However, instead of calculating the SWE, it will assume that
the SWE is zero. Then, it will perform the inverse SWE calculation,
and infer the values of the n0Ke and n0Tl from the measured
integrals for the K and Tl isotope peaks, taking into account the
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