NCAR Airborne Instrumentation Inventory

1. INSTRUMENT IDENTIFICATION

Instrument Designation:
Tunable Diode Laser Absorption Spectrometer

Instrument Acronym:
DCALS (Dual Channel Airborne Laser Spectrometer)

Instrument Measurements:

a) Trace Gas
Formaldehyde

b) Cloud Physics/Aerosol


c) Radiation/Optical/Electrical


d) Additional Capabilities


Resource Person/Developer:


Name:	Alan Fried	Bryan P. Wert
Affiliation:	ACD	ACD
Phone:	(303) 497-1475	(303) 497-1451
Email:	fried@ucar.edu	bwert@ucar.edu

Principle of Measurement:
Infrared Absorption

In situ/Remote/Flux Measurement:
in situ

2. INSTRUMENT APPLICATION

Scientific questions to be answered:
Hydrocarbon oxidation and ozone production mechanism

Field projects in which the instrument has been used:
NARE 96, STERAO A

Publications describing the instrument, applications and field project results:
B.P. Wert, A. Fried, B. Henry, J.R. Drummond: Proceedings Reprint, SPIE ( International Society for Optical Engineering), Vol. 2834 ,175 (1996): Application of tunable diode and other infrafed sources for atmospheric studies and industrial process monitoring

3. Instrument Deployment

Altitude:
0 to 26,000 ft

Aircraft Platform:
NOAA P3

Inlet Configuration/Location:
standard inlet, rear-facing, with heated winglet

Calibration/Cross Calibration:
Gas phase standards at about 5 ppbv level
every 20 min, at inlet entrance

Operator Requirements:
one

Data Collection:
self

Post-flight Data Validation, Processing, Hours per Flight Hour etc.
Data fitting and inspection of data quality

Physical Characteristics:
Dimensions: 40x30x36 in
Weight: 450-500 lbs
Power: 5 amp, 110 V, 60 Hz
Other:

4. Instrument Performance

Linear Range:
0 to > 100 ppmv

Response Time:
20 sec to 3 min, depending upon desired signal to noice ratio

Detection Limits:
80 pptv to 40 pptv for the above times

Accuracy:
5% of ambient concentration + detection limit

Precision:
at 1000 times the detection limit precision is approximately 0.1 - 0.2%

Limitations (such as altitude, airspeed, etc.)
none known

5. Alternative Techniques

6. Status/Plans

7. Comments