Calorimetric gas sensor
Abstract
A combustible gas sensor is described 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 {micro}m thick {times} 10{micro}m wide {times} 100, 250, 500, or 1000 {micro}m-long polycrystalline Si; some are overcoated with a 0.25 {micro}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 C; Pt deposits only on the hot filament. Using a constant-resistance-mode feedback circuit, Pt-coated filaments operating at ca. 300 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. 11 figs.
- Inventors:
- Issue Date:
- Research Org.:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- Sponsoring Org.:
- USDOE, Washington, DC (United States)
- OSTI Identifier:
- 675786
- Patent Number(s):
- 5834627
- Application Number:
- PAN: 8-766,142
- Assignee:
- Sandia Corp., Albuquerque, NM (United States)
- DOE Contract Number:
- AC04-94AL85000
- Resource Type:
- Patent
- Resource Relation:
- Other Information: PBD: 10 Nov 1998
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 08 HYDROGEN FUEL; CALORIMETERS; GAS ANALYSIS; POLYCRYSTALS; SILICON; PLATINUM; HYDROGEN
Citation Formats
Ricco, A J, Hughes, R C, Smith, J H, Moreno, D J, Manginell, R P, Senturia, S D, and Huber, R J. Calorimetric gas sensor. United States: N. p., 1998.
Web.
Ricco, A J, Hughes, R C, Smith, J H, Moreno, D J, Manginell, R P, Senturia, S D, & Huber, R J. Calorimetric gas sensor. United States.
Ricco, A J, Hughes, R C, Smith, J H, Moreno, D J, Manginell, R P, Senturia, S D, and Huber, R J. Tue .
"Calorimetric gas sensor". United States.
@article{osti_675786,
title = {Calorimetric gas sensor},
author = {Ricco, A J and Hughes, R C and Smith, J H and Moreno, D J and Manginell, R P and Senturia, S D and Huber, R J},
abstractNote = {A combustible gas sensor is described 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 {micro}m thick {times} 10{micro}m wide {times} 100, 250, 500, or 1000 {micro}m-long polycrystalline Si; some are overcoated with a 0.25 {micro}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 C; Pt deposits only on the hot filament. Using a constant-resistance-mode feedback circuit, Pt-coated filaments operating at ca. 300 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. 11 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Nov 10 00:00:00 EST 1998},
month = {Tue Nov 10 00:00:00 EST 1998}
}