Campbell IRGASON, Руководство по эксплуатации продукта

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Table 8-1: USB and RS-485 output elements
Data
element
Description Units/comments
12
H
2
O Signal Strength
Nominally 0.0 to 1.0
13
CO
2
Density from Fast-response Temperature
1/
mg·m
–3
14 Source Housing Temperature °C
15 Detector Housing Temperature °C
16 Counter Arbitrary
17 Signature Arbitrary in hexadecimal
1/
This additional CO
2
density output is available in EC100 OS version 7.01 or later. It uses humidity-corrected sonic
temperature instead of ambient temperature measured by the EC100 temperature probe in the conversion of
absorption measurements to CO
2
density. Using the sonic anemometer’s fast-response temperature
measurements, compensates for spectroscopic effects during high sensible heat flux regimes as explained in
Helbig
et al. (2016).
NOTE:
An open-path gas analyzer connected to an EC100 running an OS version less than 7.01, the
13th data field/element is unused, If a closed-path gas analyzer (for example, an EC155) is
connected to the EC100, this data field/element will be the sample cell pressure differential.
FIGURE 8-1. An example of USB data output in terminal mode
The final data element in each row or output array is the signature. The signature is a four
character hexadecimal value that is a function of the sequence and number of bytes in the output
array. The recording device (such as a PC or data logger) calculates its own signature using each
transmitted byte until encountering the transmitted signature. The computed signature and the
transmitted signature are compared. If they match, the data were received correctly. This is very
similar to a cyclic redundancy check (CRC).
IRGASON® Integrated CO
2
/H
2
O Open-Path Gas Analyzer and 3D Sonic Anemometer 29