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US 6,503,758 B1Granted
Systems and methods for measuring nitrate levels
AssigneePresident and Fellows of Harvard College
InventorsGeorge A. Allen, Petros Koutrakis, Yiming Ding
Life of this patent
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Abstract
The systems and methods described herein relate to the measurement of nitrate levels in a sample of gas, for example, air, exhaust, or other sources of gas. Moreover, the systems and methods described herein are capable of operating using short sample collection periods, permitting rapid data collection and finely time-resolved nitrate monitoring over a span of time. Additionally, ambient nitrate can effectively be distinguished from other airborne particles, such as sulfate and carbon.
Claims2
A system for measuring nitrate levels, comprising
- a sample inlet for receiving a sample of gas,
- a collection body coupled to said sample inlet,
- a filter mounted within said body to collect particles from said sample of gas,
- a heater coupled to the body to heat the body,
- a gas inlet coupled to said body to provide a flow of gas through said body,
- a detector coupled to said body to measure an NOx concentration, and
- an extractor coupled to said sample inlet and to said collection body to substantially remove NO2 from the gas sample, wherein the extractor comprises a hydroxyl-bearing solvent and a base, and further wherein the hydroxyl-bearing solvent is glycerol and the base is an organic base.
4 more elements
Dependencies are inferred from the claim text.