The instrumentation breakout group was attended by the following participants during at least a portion of the discussion on Wednesday afternoon:

Rich Barchet (PNNL)
Carl Berkowitz (PNNL)
Peter Daum (BNL)
Paul Doskey (ANL)
Richard Larsen (EML)
Winston Luke (NOAA/ARL)
Bob McMillan (NOAA/ARL)
Lenny Newman (BNL)
Chet Spicer (Battelle)
Steve Springston (BNL)
Marv Wesely (ANL)
Judy Weinstein-Lloyd (SUNY-Old Westbury)

Many measurement and instrumentation skills exist within the ACP. The Argonne National Laboratory (ANL) is a leader in VOC and PAN measurements. Battelle Columbus is a leader in trace gas mass spectroscopic, PAN, and VOC measurements. The Brookhaven National Laboratory (BNL) is a leader in NO_x/NO_y, peroxide, and carbonyl measurements. The Environmental Measurements Laboratory (EML) leads the way in aerosol measurements and characterization. The Pacific Northwest National Laboratory (PNNL) provides physical measurements of the ambient environment. SUNY- Old Westbury collaborates with BNL on peroxide measurements. The University of Minnesota collaborates on ultra-fine aerosol measurements.

Our discussion of ACP instrumentation largely focused on the instrumentation needs of the Gulfstream 1 aircraft, a DOE Research Aircraft Facility (RAF) operated by the Pacific Northwest National Laboratory that can be used by all of the ACP community. The RAF depends on all of the ACP scientific community to provide state of the art instrumentation for the G-1. As more ACP PIs devise research programs that use the G-1, the need to engage other PIs to provide specific instrumentation will grow. As in all collaborative research endeavors, each PI on the team must identify his/her own research goals and objectives as well as support those of the team. And, as resources for mounting major field studies decline, the programmatic need for such collaboration among ACP researchers will continue to intensify.

Standard aircraft instrumentation must be mature, proven technology that requires minimal attention yet gives reliable operation. G-1 standard instrumentation is typically integral to the airframe: gust probe, radiometers, particle and aerosol probes, meteorological sensors, navigation and aircraft attitude, and the instrumentation data acquisition and display systems. Most research grade instrumentation that requires significant operator attention is not a candidate for independent operation on the G-1. Such instruments require the collaborative effort of their designers.

Improvements in the instrumentation used on the G-1 are driven by the need for increased sensitivity, faster response, and more reliable operation. As the ACP conducts investigations into more remote regions, instruments with lower limits of detection become increasingly more important to field studies. Faster response times are required of instruments so that spatial features of ever smaller dimensions can be resolved from the moving aircraft platform and so that advanced data analysis methods can be used to extract new information from the measured signal. Instrument reliability covers many aspects of instrument operation. Reducing the extent of operator intervention during flight, automating calibration procedures, and reducing the physical size, weight, and power consumption add to instrument reliability.

The following instrumentation and measurement capabilities have recently been upgraded or improved on the G-1:

SO₂
Through fine tuning and component optimization, BNL is able to significantly speed up the response time while also increasing the sensitivity of a standard TECO 43S instrument to enhance the detection of power plant plumes.

O₃
A manufacturer's upgrade of the standard TECO 49 instrument gives the faster response time needed for doing plume studies and applying corrections for O₃ needed by NO_y instruments. However, the still faster response times needed for eddy correlation studies requires the use of instruments based on dry chemiluminescence techniques.

PAN
Improvements in gas chormatographic measurement of PAN achieved by Battelle Columbus provide the sensitivity for making PAN measurements in remote areas. ANL is working on short column gas chromatographic methods for reducing the response time and measuring NO₂ at the same time.

CO
BNL developed instrument tuning and optimization methods that both reduced the zero drift common with these instruments and increased their sensitivity. However, faster response will require a shift to a UV fluorescence detection method.

NO_x/NO_y
Converter efficiencies and NO measurement capability are now sufficiently understood that the performance of the inlet to the NO_y-to-NO converter is the main source of uncertainty in instrument performance. An ACP effort is being coordinated this year by BNL to investigate inlet performance.

Total Nitrate
BNL is developing a wet scrubbing method for in flight measurements. Inlet performance is also an issue for this measurement.

HONO/HNO₃
The Battelle Columbus TAGA mass spectrometer is now the only ACP instrument capable of this measurement. A more compact, lighter instrument would be preferred. BNL has proposed a wet scrubbing method but significant additional development is needed.

VOC
Canister sampling, which can provided time integrated or quick grab samples, requires post-flight gas chromatographic or mass spectroscopic analysis. Near real time sampling and readout of VOC concentrations in flight is desirable for detecting plumes. ANL will soon test fly a new VOC gas chromatograph.

Peroxides
SUNY-Old Westbury collaborated with BNL to convert a PNNL peroxide dual channel instrument into a three channel system for measuring H₂O₂, methyl hydroperoxide (MHP), and hydroxymethyl hydroperoxide (HMHP).

Carbonyl
BNL has developed an air sampling system that uses wet scrubbing to produce samples that are analyzed post-flight for carbonyl compounds.

Aerosols
PNNL upgraded the aerosol size measuring instrument from an ASASP-100X to a PCASP-100X which extended its range down to 0.10 m, stabilized laser power output, and reduced the frequency for maintenance.

Attitude
Replacing the G-1's inertial navigation system with a differential GPS system significantly reduced the weight and power required to obtain aircraft attitude data needed for calculating gust probe winds.