| Description: | DQR No: Platform: SIROS
Subject: Site E2 - NIP (pyrheliometer) calibration coefficient
slightly wrong for a period of 5 days
Date Submitted: 1 May 1996
Submitted By: Jim Barnard _X_ Instrument Mentor
___ EST Member
___ Science Team Member
___ Other _____________________________
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at problems@arm.gov.
Platform/Measurement:
What level data: (raw,a0,a1,b1,c1 etc): a1
What location was the data collected at:
Period of time in question
Begin Date 96/04/19 Time 15:20 (GMT)
End Date 96/04/24 Time 00:00 (GMT)
(For the NIP, some errors are occasionally observed after the "End Date").
Data should be labeled:
___ questionable ___ All data fields affected
___ incorrect _x_ Only some data fields affected
_x_ wrong calibration
___ others
Discussion of Problem: The NIP (pyrheliometer) at site E2 was changed
on April 19, 1996 at about 1530 GMT. When the NIP was changed, the data
ingest was not turned off and continued insouciantly. Later, the mentor
was informed about the change and a new calibration file was submitted.
This file was applied to the ingested data about April 24, 1996.
Instead of redoing the ingest from April 19, 1996 to April 24, 1996,
we are submitting this DQR to inform people that the NIP calibration
during this time period is not correct. The calibration factor
applied to these data during this period is 8.513 x 10^-6 Volts/W/M^2,
while the true calibration factor is 8.546 x 10^-6 Volts/W/M^2. This
factor is being applied to all the NIP data collected from April 24, 1996
on. Note that the error caused by using the incorrect calibration
factor is less than 0.4%.
Other observations/measurements impacted by this problem:
Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)
The error is so small that it can probably be ignored; from a
practical standpoint, this DQR is submitted for the sake of
completeness. |