Campbell CPEC300, Руководство по эксплуатации продукта

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CPEC300/306/310 Closed-Path Eddy-Covariance Systems
80
8. Footprint characteristics are computed using Kljun et al (2004) and
Kormann and Meixner (2001).
The appendices in the EasyFlux DL CR6OP manual describe the
implementation of the major corrections in EasyFlux DL CR6CP ,
with the exception of frequency correction for tube attenuation,
which is described in Ibrom et al. 2007, Burgon et al. 2016, and
the code itself. It should also be noted that the appendix on WPL
density corrections for open-path is not applicable here since the
closed-path analyzer gas concentrations are output as dry molar
mixing ratios.
7. Zero and Span
Since a CPEC310 system includes a valve module, it may be configured to
self-initiate an automatic zero and span of the EC155 gas analyzer. The timing,
whether the system will simply check the drift or actually set new zero/span
coefficients, and whether the automatic zero/span will include an H
2
O span, are
all determined by user-entered constants relating to a CPEC310 (see constants
that are indented under the constant “CPEC310” in TABLE 6-1 , Program
Constants) . An automatic zero and span cycle on a CPEC310 may be manually
initiated at any time; instructions to do so are found in Section 7.1 , User-
Initiated Zero/Span for CPEC310
(p. 84)
.
For CPEC310 systems that are not set up with a continuously available source
of H
2
O span gas, which is typically the case, H
2
O spans must be manually
setup and initiated by the user. More details are found in Section 7.1.2 ,
CPEC310 Manual H2O Span
(p. 86).
CPEC300 and CPEC306 systems require the user to manually setup and
initiate the zero, CO
2
span, and/or H
2
O span since these systems do not include
a valve module. More details are found under Section 7.2 , User-Initiated
Manual Zero/Span for CPEC300 or CPEC306
(p. 87)
.
Regardless of system type, perfoming a user-initiated zero or span is most
easily done using the CR1000KD keypad. This requires connecting a
CR1000KD to the CS I/O port of the CR6 datalogger and while the program is
running. Pressing Enter twice will access the main menu. Under the main
menu, use the keypad’s down arrow to scroll down until the submenu
Attendant Zero/Span is highlighted and press Enter . This menu accesses all
menus and variables needed for doing a zero and span as explained in the
sections below.
If a tall tower installation requires the CR6 to be far away from the
EC155 gas analyzer, making it inconvenient to access the
CR1000KD, it may be more practical to use a laptop running
ECMon software to set the zero and spans, as explained in the
EC155 user manual.
For reference, FIGURE 6-2 shows an organizational schematic for
all the keypad menus. To return to a previous menu at any time,
press Esc .
NOTE
NOTE