Instrument Abbreviation:
SWT, SWB
Instrument Measurements:
a) Trace Gas
b) Cloud Physics/Aerosol
c) Radiation/Optical/Electrical
Hemispheric visible radiation
d) Additional Capabilities
Resource Person/Developer:
| Name: | Krista Laursen | Bruce Morley |
|---|---|---|
| Affiliation: | NCAR/ATD/RAF | NCAR/ATD/RAF |
| Phone: | (303) 497-1031 | (303) 497-1018 |
| Email: | krista@ucar.edu | bruce@ucar.edu |
Principle of Measurement:
Incoming radiation is sensed with a thermopile of copper-constantan junctions
which are coated with Parson's black lacquer. This absorption is essentially
independent of wavelength for the passband of the pyranometer which is
determined by the filter characteristics of the domes. Usually, it is fitted
with two domes of WG295 Schott filter glass yielding a passband of 0.285 uM
to 2.80 uM. (Other filter combinations can be used to obtain different
passbands. However, the user should be aware that the RAF does not stock
all of these filters and that the pyranometers are calibrated using the
WG295 filters.)
One NCAR modification added a stable amplifier to the housing to increase the millivolt signal to a range of 0.0 to 1.0 Vdc.
In situ/Remote/Flux Measurement:
Remote
Field projects in which the instrument has been used:
most
Aircraft Platform:
all
Inlet Configuration/Location:
fuselage-mounted, up- or down-looking
Calibration/Cross Calibration:
Annual comparison with a reference pyranometer at Eppley Laboratories, Inc.
Operator Requirements:
Data Collection:
external
Post-flight Data Validation, Processing, Hours per Flight Hour etc.
RAF NIMBUS software processor
Post-project validation by RAF Project Manager
Phisical Characteristics:
Dimensions:14.6 cm diameter x 17.1 cm high
Weight: 1.8 kg
Power:
Other:
Response Time:
1.0 s time constant
Detection Limits:
0.12 W/M2
Accuracy:
± 1.5 %
Precision:
Limitations (such as altitude, airspeed, etc.)