NASA Technical Reports Server (NTRS) 20020080175: Analyzing Water's Optical Absorption

1 Pages·0.06 MB·English

by  NASA Technical Reports Server (NTRS)

Analyzing Water’s Optical Absorption
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cooperative agreement between World On a technical note, UltraPath is a unique,
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Precision Instruments (WPI), Inc., of high-performance absorbance spectrophotometer F
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Sarasota, Florida, and NASA’s Stennis with user-selectable light path lengths of 2, 10, N
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Space Center has led to a new innovation that 50, and 200 cm. It is an ideal tool for any —S
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benefits both NASA and the general scientific study requiring precise and highly sensitive FIT
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community. After a collaboration with Dr. spectroscopic determination of analytes, either in N
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Richard Miller, a NASA chief scientist and the laboratory or in the field. The instrument L
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biological oceanographer, WPI is marketing its operates in the wavelength range of 370 nanom- CI
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UltraPath™ device, which provides a more eters (nm) to 725 nm and has a dynamic range M
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efficient method for analyzing the optical allowing reliable absorbance measurements CO
absorption of water samples at sea. between 5 micro absorbance units per centime-
Dr. Miller, who conducts research aboard ter (mAU/cm) to 1 absorbance unit per centi-
ships around the globe to support NASA’s meter (AU/cm).
satellite programs, initiated the development of As a low-cost, rugged, and portable system
UltraPath. He collects water samples to verify capable of high-sensitivity measurements in
observations from space by examining colored widely divergent waters, UltraPath meets
dissolved organic matter (CDOM), a major Dr. Miller’s needs while providing commercial
component of land runoff that affects ocean opportunities for WPI. Dr. Miller explained,
color in coastal waters. Since the presence of “The flexibility of the system solves a critical
CDOM complicates the detection of other problem for oceanographers and opens the door
materials using ocean color sensors, measuring to numerous other applications.” The product
how much light CDOM absorbs helps scientists will help scientists examine the role that
to evaluate the accuracy of products developed coastal ocean environments play in the global
from satellite imagery. The standard method of carbon cycle. ❖
measuring the absorption of water samples
requires special handling and storage. According UltraPath™ is a trademark of World Precision Instruments,
to Dr. Miller, the procedure involves freezing Inc.
the seawater samples and shipping them to a LWCC™ is a trademark of World Precision Instruments,
Inc.
laboratory for spectral analysis.
To avoid this time-consuming and costly
process, Dr. Miller teamed with WPI, an
international manufacturer of laboratory equip-
ment, to develop a portable, yet robust, system.
Dr. Miller gained financial support for the
UltraPath project through a dual-use cooperative
agreement between Stennis’ Office of Technol-
ogy Transfer and WPI. The company’s recog-
nized expertise in the field of liquid waveguide
capillary cell technology (LWCC™) served as a
platform for UltraPath’s design. Dr. Mathias
Belz, senior scientist for the company, stated,
“The [Technology Transfer’s] Dual-Use program
has provided both partners with the opportunity
to combine NASA’s vast knowledge of oceanol-
ogy with WPI’s expertise in optical instrumenta-
tion, resulting in the successful design of
UltraPath.”
The innovative UltraPath™ is a
“multiple pathlength” optical system.
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