Infrared oil-concentration meter
AssigneeHoriba, Ltd.
InventorsHiroshi Fujii, Ryosuke Fukushima, Tatsuhide Tsutsui, Masahiko Ishida, Shuzi Takada
Life of this patent
Estimating the term…
Abstract
An oil concentration meter includes a sample cell for receiving an oil sample that can be irradiated with infrared rays from a light source. A first interference filter having a design wavelength of 3.4 .mu.m is positioned before a measuring detector, while a second interference filter transmitting a band range between 1 .mu.m and 5 .mu.m is positioned in front of a reference detector. A logarithm of the ratio of the reference detector output to the measuring detector output is used for determining the oil concentration in a sample.
Claims12
An oil-concentration meter comprising:
- a sample cell for receiving an oil sample;
- a light source for applying infrared rays to the sample cell, where a sample containing oils in solvents is supplied, said light source being arranged on one end side of said cell;
- a measuring detector and a reference detector for receiving infrared rays, which have been transmitted through the sample cell, respectively, are provided on the other end side of the sample cell;
- a first interference filter having an optical filter with a design wavelength of 3.4 .mu.m which transmits only absorption wavelengths characteristics of said oil sample is provided in an optical path of said measuring detector;
- and
- a second interference filter having flat transmission characteristics over a range of 1 .mu.m to 5 .mu.m, including said absorption wavelengths by the oil sample is provided in an optical path of said reference detector, whereby the outputs of the measuring detector and the reference detector are used to determine the oil concentrations in the sample.
A fuel oil concentration meter comprising:
- a light source of infrared light;
- a sample cell transmissive of the infrared light from the light source located on one side of the sample cell, and adapted to receive an oil sample;
- a measuring detector;
- a reference detector located on the other side of the sample cell with the measuring detector, the reference detector and the measuring detector receiving light from the light source which has passed through the sample cell;
- a first interference filter having a design wavelength of approximately 3.4 .mu.m positioned between the measuring detector and the source;
- a second interference filter having a band pass of approximately 1 .mu.m to 5 .mu.m positioned between the reference detector and the source;
- means for providing digital output signals representative of the measuring detector output signal I, and the reference detector output signal I.sub.0 ;
- and
- means for calculating a log (I.sub.0 /I) to determine the oil concentration in the oil sample.
Dependencies are inferred from the claim text.