| Description: | The AMF VCEIL had lower-than-normal laser transmitter power, ~84%, so the instrument was
replaced with a spare on 4/22. The spare VCEIL had just been repaired but began to display
receiver failure warnings.
Diagnostic information was sent to Vaisala and we discussed either replacing the receiver
with the one from the original VCEIL (with the degraded transmitter) or replacing the
transmitter in the original VCEIL with the one from the spare. Vaisala recommended the
latter because the original VCEIL is a much newer unit.
On 5/16, the site operator replaced the transmitter in the original VCEIL with the one
from the spare, realigned the optics, recalibrated the laser, and put the instrument back
into service, successfully correcting the problem.
The data during this period were intermittently incorrect, containing warning flags and
alarms and unreasonable cloud base heights. |