Appendix B. Calibration
validation
Use the
XTEST!
SDI-12 command to validate the calibration. Enter this command in the
transparent mode while the computer is communicating with the data logger through a terminal
emulator program.
This command displays simulated rain fall data that does not affect rain accumulators used for
the normal operation. It runs for 60 minutes then returns to normal operation. The
XTEST!
command can also be aborted by a break on the SDI-12 data line. Therefore, suspend the data
logger program before you begin field calibration.
To validate the calibration, first run a fixed amount of water through the RainVUE-series, then use
the
XTEST!
command and compare the results. A common amount of simulated rain is 946 ml,
which equates to 115 tips on the 0.01-inch rain gage at a rate of 2 inches of rain per hour or
slower.
Initially, the command sends the following header information:
Raw
Tip
Corrected
Rain Fall
Total
Rain Fall
Balance
For each second or each tip detected, the command displays a new line of data, such as the
following:
Raw
Tip
Corrected
Rain Fall
Total
Rain Fall
Balance
0
0.000
0.000
0
0
0.000
0.000
0
Eventually, the numbers should start changing, and the latest data should give an indication of
how close the gage is to calibration.
RainVUE-Series SDI-12 Precipitation Sensors
35
