Method of and apparatus for measuring vapor density

Patent · Sat Dec 31 23:00:00 EST 1988

OSTI ID:867135

Nelson, Loren D ^[1]; Cerni, Todd A ^[2]

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1. Morrison, CO
2. Littleton, CO

Apparatus and method determine the concentration of an individual component, such as water vapor, of a multi-component mixture, such as a gaseous mixture for cooling a nuclear reactor. A hygrometer apparatus includes an infrared source for producing a broadband infrared energy beam that includes a strong water vapor absorption band and a weak water vapor absorption region. The beam is chopped to select infrared pulses. A temporally first pulse has a wavelength in the weakly absorbing region, a temporally second pulse has a wavelength in the strong band and a temporally third pulse has a wavlength in the weakly absorbing region. A fourth reference pulse representing background radiation is interposed in such chopped pulses. An indium arsenide infrared sensor is responsive to the pulses for generating an output signal in proportion to: ##EQU1## where N1 is proportional to the transmission through the sample of the first signal, N4 is related to the background radiation, and [K2 (N2-N4)+K3 (N3-N4)] is the time-weighted average of the transmission through the sample of the second and third pulses applicable at the time of the second pulse, with the reference pulse N4 being subtracted in each case to render the ratio independent of variations in the background radiation.

• Research Organization: Ophir Corp
• DOE Contract Number: AC03-83ER80090
• Assignee: Ophir Corporation (CO)
• Patent Number(s): US 4874572
• OSTI ID: 867135
• Country of Publication: United States
• Language: English

Related Subjects

/376/250/976/
absorbing
absorbing region
absorption
absorption band
apparatus
applicable
arsenide
average
background
background radiation
band
beam
broadband
chopped
component
concentration
cooling
density
determine
energy
energy beam
equ1
fourth
gaseous
gaseous mixture
generating
hygrometer
independent
indium
individual
individual component
infrared
infrared energy
infrared source
interposed
k2
k3
measuring
method
mixture
multi-component
multi-component mixture
n1
n2-n4
n3-n4
n4
nuclear
nuclear reactor
output
output signal
producing
proportion
proportional
pulse
pulses
radiation
ratio
reactor
reference
reference pulse
region
related
render
representing
responsive
sample
select
sensor
signal
source
strong
subtracted
temporally
third
time
time-weighted
transmission
vapor
vapor density
variations
water
water vapor
wavelength
wavlength
weak
weakly