Calorimetric gas sensor
Abstract
A combustible gas sensor that uses a resistively heated, noble metal-coated, micromachined polycrystalline Si filament to calorimetrically detect the presence and concentration of combustible gases. The filaments tested to date are 2 .mu.m thick.times.10 .mu.m wide.times.100, 250, 500, or 1000 .mu.m-long polycrystalline Si; some are overcoated with a 0.25 .mu.m-thick protective CVD Si.sub.3 N.sub.4 layer. A thin catalytic Pt film was deposited by CVD from the precursor Pt(acac).sub.2 onto microfilaments resistively heated to approximately 500.degree. C.; Pt deposits only on the hot filament. Using a constant-resistance-mode feedback circuit, Pt-coated filaments operating at ca. 300.degree. C. (35 mW input power) respond linearly, in terms of the change in supply current required to maintain constant resistance (temperature), to H.sub.2 concentrations between 100 ppm and 1% in an 80/20 N.sub.2 /O.sub.2 mixture. Other catalytic materials can also be used.
- Inventors:
-
- Albuquerque, NM
- Cedar Crest, NM
- Brookline, MA
- Bountiful, UT
- Issue Date:
- Research Org.:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- OSTI Identifier:
- 871967
- Patent Number(s):
- 5834627
- Assignee:
- Sandia Corporation (Albuquerque, NM)
- Patent Classifications (CPCs):
-
G - PHYSICS G01 - MEASURING G01N - INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- DOE Contract Number:
- AC04-94AL85000
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- calorimetric; gas; sensor; combustible; resistively; heated; noble; metal-coated; micromachined; polycrystalline; filament; calorimetrically; detect; presence; concentration; gases; filaments; tested; date; thick; times; 10; wide; 100; 250; 500; 1000; m-long; overcoated; 25; m-thick; protective; cvd; layer; catalytic; film; deposited; precursor; acac; microfilaments; approximately; degree; deposits; hot; constant-resistance-mode; feedback; circuit; pt-coated; operating; 300; 35; mw; input; power; respond; linearly; terms; change; supply; current; required; maintain; constant; resistance; temperature; concentrations; ppm; 80; 20; mixture; materials; combustible gases; feedback circuit; input power; noble metal; combustible gas; catalytic material; gas sensor; hot filament; resistively heated; catalytic materials; noble metal-coated; micromachined polycrystalline; maintain constant; filaments tested; calorimetrically detect; /73/422/
Citation Formats
Ricco, Antonio J, Hughes, Robert C, Smith, James H, Moreno, Daniel J, Manginell, Ronald P, Senturia, Stephen D, and Huber, Robert J. Calorimetric gas sensor. United States: N. p., 1998.
Web.
Ricco, Antonio J, Hughes, Robert C, Smith, James H, Moreno, Daniel J, Manginell, Ronald P, Senturia, Stephen D, & Huber, Robert J. Calorimetric gas sensor. United States.
Ricco, Antonio J, Hughes, Robert C, Smith, James H, Moreno, Daniel J, Manginell, Ronald P, Senturia, Stephen D, and Huber, Robert J. Thu .
"Calorimetric gas sensor". United States. https://www.osti.gov/servlets/purl/871967.
@article{osti_871967,
title = {Calorimetric gas sensor},
author = {Ricco, Antonio J and Hughes, Robert C and Smith, James H and Moreno, Daniel J and Manginell, Ronald P and Senturia, Stephen D and Huber, Robert J},
abstractNote = {A combustible gas sensor that uses a resistively heated, noble metal-coated, micromachined polycrystalline Si filament to calorimetrically detect the presence and concentration of combustible gases. The filaments tested to date are 2 .mu.m thick.times.10 .mu.m wide.times.100, 250, 500, or 1000 .mu.m-long polycrystalline Si; some are overcoated with a 0.25 .mu.m-thick protective CVD Si.sub.3 N.sub.4 layer. A thin catalytic Pt film was deposited by CVD from the precursor Pt(acac).sub.2 onto microfilaments resistively heated to approximately 500.degree. C.; Pt deposits only on the hot filament. Using a constant-resistance-mode feedback circuit, Pt-coated filaments operating at ca. 300.degree. C. (35 mW input power) respond linearly, in terms of the change in supply current required to maintain constant resistance (temperature), to H.sub.2 concentrations between 100 ppm and 1% in an 80/20 N.sub.2 /O.sub.2 mixture. Other catalytic materials can also be used.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 1998},
month = {Thu Jan 01 00:00:00 EST 1998}
}