CA2202314A1 - Method for determining surface moisture level - Google Patents
Method for determining surface moisture levelInfo
- Publication number
- CA2202314A1 CA2202314A1 CA002202314A CA2202314A CA2202314A1 CA 2202314 A1 CA2202314 A1 CA 2202314A1 CA 002202314 A CA002202314 A CA 002202314A CA 2202314 A CA2202314 A CA 2202314A CA 2202314 A1 CA2202314 A1 CA 2202314A1
- Authority
- CA
- Canada
- Prior art keywords
- light
- moisture level
- prism
- surface moisture
- photoelectric transducer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims description 6
- 238000005259 measurement Methods 0.000 claims abstract description 11
- 239000000463 material Substances 0.000 claims description 8
- 230000035945 sensitivity Effects 0.000 claims description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 4
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims description 4
- 238000011144 upstream manufacturing Methods 0.000 claims description 4
- 206010021639 Incontinence Diseases 0.000 claims description 3
- 239000004753 textile Substances 0.000 claims description 3
- 239000005662 Paraffin oil Substances 0.000 claims description 2
- 230000002745 absorbent Effects 0.000 claims description 2
- 239000002250 absorbent Substances 0.000 claims description 2
- 239000007864 aqueous solution Substances 0.000 claims description 2
- 239000002480 mineral oil Substances 0.000 claims description 2
- 235000010446 mineral oil Nutrition 0.000 claims description 2
- 239000003921 oil Substances 0.000 claims description 2
- 229920002545 silicone oil Polymers 0.000 claims description 2
- 230000000737 periodic effect Effects 0.000 claims 2
- 239000012530 fluid Substances 0.000 claims 1
- 150000002894 organic compounds Chemical class 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims 1
- 239000011521 glass Substances 0.000 description 3
- CPBQJMYROZQQJC-UHFFFAOYSA-N helium neon Chemical compound [He].[Ne] CPBQJMYROZQQJC-UHFFFAOYSA-N 0.000 description 2
- 239000004745 nonwoven fabric Substances 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 230000003595 spectral effect Effects 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- -1 for example Substances 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
- G01N21/43—Refractivity; Phase-affecting properties, e.g. optical path length by measuring critical angle
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
A device for determining the surface moisture level by means of scattering a light beam at the base of an inverting prism which rests on the test specimen, whereinmonochromatic, pulsed or monochromatically pulsed light is used for the measurement.
Description
HOECHST AKTIENGESELLSCHAFT HOE 96/F 093 Dr. KM/St Description 5 Device for determining surface moisture level The invention relates to a device which is suitable for determining the surface moisture level, in particular of sorptive, liquid-absorbing or liquid-relaying two-10 dimensional structures such as, for example, filter paper, baby diapers, sanitarynapkins, incontinence diapers, patient undersheets, nonwovens, textiles. Moreover, in the case of materials having a homogeneous moisture distribution the determination of the surface moisture level can be used to state the moisture level in the interior of the material.
EP-A-0 312 919 discloses a method for measuring the surface moisture level, whose principle is the total reflection of a continuous light beam at the base face of a Dove prism. The scattering of the light, which occurs in addition to the totalreflection, at the base face changes its intensity when the base face is brought into 20 contact with a damp surface.
It has surprisingly be,en found that the disturbing influences of extraneous light which occur during measurements in accordance with the prior art methods can be minimized by using monochromatic light and/or by pulsing the light source and the 25 detector, or an amplifier, which may be connected downstream of the detector-electronically, mechanically or electro-optically at a prescribed frequency.
The subject-matter of the invention is a device for determining the surface moisture level of sorptive or liquid-absorbing, two-dimensional structures and materials,30 essentially comprising a Dove inverting prism (1), a light source (2) which is arranged such that its parallel-directed light beams (2a) impinge perpendicularly on one of the short faces (3) of the prism (1 ) and are reflected by the hypotenuse face of the prism (1), which is brought into contact with the surface (9) to be measured with respect to moisture level, a light trap (4) which is arranged such that the beams (2c) reflected by the hypotenuse face impinge on it, and a photoelectric transducer (10) which is located in the right angle formed by the two short faces (3) and (5) and arranged such that its measuring surface is situated opposite and parallel to the hypotenuse face of the prism, and which converts the light (2b) scattered by thesurface (9) to be measured with respect to moisture level into a measuring signal, wherein a) the light used for the measurement has a known, fixed wavelength, and wherein a1 ) located upstream of the photoelectric transducer (10) is a filter which passes only this wavelength, or wherein a2) the photoelectric transducer (10) is sensitive only to this wavelength, or wherein b1) the light used for the measurement is pulsed, starting from its generation, at a known, fixed frequency or is pulsed by a suitable device, which is located in the light beam (2a) upstream of the entry into the prism (1), and wherein b2) the photoelectric transducer (10) is operated with selective sensitivity to the known fixed frequency, and wherein its output signal is amplified with selective sensitivity to this frequency, or wherein c) in a combination of both methods, light of a known, fixed wavelength and of a known, fixed frequency is used.
s A preferred embodiment of this invention is represented in Figure 1. The light source (2) is positioned above one short face (3) of a right-angled prism (1). The 25 parallel light beams (2a) originating from this light source traverse the prism and strike the glass/air interface at the hypotenuse surface. To align the light beams in parallel, it is possible to use stops (6) in the beam path, and the short face can be covered with an opaque layer (7) at the points at which no light is to be incident. If the hypotenuse face of this prism rests on a dry surface, because of the slight 30 contact between the glass and the surface of the object to be measured there is total reflection of the incident light and the greater part (2c) leaves the prism through the second short face (5) and is absorbed by the light trap (4). In accordance with the slight contact between the surface (9) and the hypotenuse face, a small proportion of scattered light (2b) is generated and reaches the photoelectric transducer (10). The light trap has the form of a black cavity. In a practical embodiment of this device, such a light trap can be provided by a housing of thedevice if said housing is roughened and blackened.
If, as represented in Figure 2, the hypotenuse face of the prism rests on a moist surface, the light beam leaves the prism at the hypotenuse face and is scattered at the irregular surface (9) of the test specimen (8). The greater part of the scattered light (2b) passes again into the glass prism and strikes a photoelectric transducer 10 (10) which is located in the angle formed by the short faces exactly opposite the hypotenuse face. The relevant useful signal generated in this photoelectric transducer (10) is proportional to the moisture level of the surface of the testspecimen and is displayed using appropriate measuring units. The measuring operations can advantageously be recorded as a function of time with the aid of a 15 chart recorder.
For acceptable measurement, the hypotenuse face of the prism must remain directly in contact with the surface to be tested. This is already achieved by the dead weight of the prism resting on the surface to be tested. By applying additional weights, this 20 contact with the surface to be measured can be intensified, in particular in the case of soft, elastic objects such as diapers, for example. Conversely, it is also possible to keep the applied weight as small as possible by inverting the prism such that the hypotenuse face comes to lie upwards, and the object to be measured is then placed on the hypotenuse surface.
The generation of pulsed light radiation can be performed in a mechanical way byinterrupting the light of a continuously operating light source by means of a mechanical chopper periodically at a known frequency. Electronically, such light can be generated by modulating the intensity of the light emitted by the light source at a 30 frequency prescribed from outside. It is likewise possible periodically to interrupt the light beam of a continuous source by means of an electro-optic component, for example, by means of a Pockels cell.
Owing to the use according to the invention of monochromatic light, pulsed lightsources, spectral filters and frequency-selective photoelectric transducers (10)and/or amplifiers, the device is insensitive to the incidence of extraneous light.
5 Lasers, for example helium neon lasers, or laser diodes are preferably used as light sources. The wavelength can be in the visible or infrared spectral region.
The device according to the invention is particularly suitable for examining hygiene articles such as, for example, baby diapers, incontinence diapers, sanitary napkins, 10 hospital bed undersheets, nonwovens and textile fabrics.
Surprisingly, it has been found that this measuring system can also be extended to technical applications. Thus, for example, it is also possible to examine technical two-dimensional absorbent materials in the case of which the surface moisture level 15 is caused not only by aqueous solutions but also by organic liquids such as, for example, isopropanol, ethanol or oils, such as, for example, paraffin oil, silicone oil and mineral oil.
Example 1 The surface moisture level of diapers was measured with and without incidence ofextraneous light. The light source used was a type LD 242 laser diode, which emits light of wavelength 880 nm at a power of 8 mW/sr. The radiation of the light source was modulated with a frequency taken 25 from a trigger generator. A type BPW 43 diode was used as photoelectric transducer. Its output signal was amplified by means of a frequency-selective amplifier into which the frequency of the trigger generator was fed as reference.
Table 1 shows the measurement results which were obtained without the incidence of extraneous light, as well as the results which where obtained with lateral 30 irradiation of the measuring device and of the diaper using a fluorescent lamp with a power of 11 W.
Table 1 Surface moisture level (%) Without extraneous light With extraneous light Comparative Example 10 The same measuring arrangement as in Example 1 was selected, but the light source and the detecting amplifier were not operated in the pulsed fashion. The measurement values obtained from the same measuring objects are shown in Table 2.
Table 2 Surface moisture level (%) Without extraneous light With extraneous light 25 ~ 35 The following Examples 2 and 3 describe other methods of generating light.
Example 2 A 12V/5W halogen lamp was used as light source. The emitted light was choppered mechanically at 9600 Hz by a slotted disc. The measurement signals were receivedby a BPY 47P silicon photoelectric cell and subsequently processed for 30 measurement purposes ina PC.
Example 3 A helium-neon laser of wavelength 632.8 nm was used as light source. The emittedlight was choppered mechanically at 9600 Hz by a slotted disc. The measured 5 signals were received by a BPW 21 photodiode, which has a measuring range of 350 - 820 nm and a sensitivity peak 550 nm, and subsequently processed metrologically in a PC.
EP-A-0 312 919 discloses a method for measuring the surface moisture level, whose principle is the total reflection of a continuous light beam at the base face of a Dove prism. The scattering of the light, which occurs in addition to the totalreflection, at the base face changes its intensity when the base face is brought into 20 contact with a damp surface.
It has surprisingly be,en found that the disturbing influences of extraneous light which occur during measurements in accordance with the prior art methods can be minimized by using monochromatic light and/or by pulsing the light source and the 25 detector, or an amplifier, which may be connected downstream of the detector-electronically, mechanically or electro-optically at a prescribed frequency.
The subject-matter of the invention is a device for determining the surface moisture level of sorptive or liquid-absorbing, two-dimensional structures and materials,30 essentially comprising a Dove inverting prism (1), a light source (2) which is arranged such that its parallel-directed light beams (2a) impinge perpendicularly on one of the short faces (3) of the prism (1 ) and are reflected by the hypotenuse face of the prism (1), which is brought into contact with the surface (9) to be measured with respect to moisture level, a light trap (4) which is arranged such that the beams (2c) reflected by the hypotenuse face impinge on it, and a photoelectric transducer (10) which is located in the right angle formed by the two short faces (3) and (5) and arranged such that its measuring surface is situated opposite and parallel to the hypotenuse face of the prism, and which converts the light (2b) scattered by thesurface (9) to be measured with respect to moisture level into a measuring signal, wherein a) the light used for the measurement has a known, fixed wavelength, and wherein a1 ) located upstream of the photoelectric transducer (10) is a filter which passes only this wavelength, or wherein a2) the photoelectric transducer (10) is sensitive only to this wavelength, or wherein b1) the light used for the measurement is pulsed, starting from its generation, at a known, fixed frequency or is pulsed by a suitable device, which is located in the light beam (2a) upstream of the entry into the prism (1), and wherein b2) the photoelectric transducer (10) is operated with selective sensitivity to the known fixed frequency, and wherein its output signal is amplified with selective sensitivity to this frequency, or wherein c) in a combination of both methods, light of a known, fixed wavelength and of a known, fixed frequency is used.
s A preferred embodiment of this invention is represented in Figure 1. The light source (2) is positioned above one short face (3) of a right-angled prism (1). The 25 parallel light beams (2a) originating from this light source traverse the prism and strike the glass/air interface at the hypotenuse surface. To align the light beams in parallel, it is possible to use stops (6) in the beam path, and the short face can be covered with an opaque layer (7) at the points at which no light is to be incident. If the hypotenuse face of this prism rests on a dry surface, because of the slight 30 contact between the glass and the surface of the object to be measured there is total reflection of the incident light and the greater part (2c) leaves the prism through the second short face (5) and is absorbed by the light trap (4). In accordance with the slight contact between the surface (9) and the hypotenuse face, a small proportion of scattered light (2b) is generated and reaches the photoelectric transducer (10). The light trap has the form of a black cavity. In a practical embodiment of this device, such a light trap can be provided by a housing of thedevice if said housing is roughened and blackened.
If, as represented in Figure 2, the hypotenuse face of the prism rests on a moist surface, the light beam leaves the prism at the hypotenuse face and is scattered at the irregular surface (9) of the test specimen (8). The greater part of the scattered light (2b) passes again into the glass prism and strikes a photoelectric transducer 10 (10) which is located in the angle formed by the short faces exactly opposite the hypotenuse face. The relevant useful signal generated in this photoelectric transducer (10) is proportional to the moisture level of the surface of the testspecimen and is displayed using appropriate measuring units. The measuring operations can advantageously be recorded as a function of time with the aid of a 15 chart recorder.
For acceptable measurement, the hypotenuse face of the prism must remain directly in contact with the surface to be tested. This is already achieved by the dead weight of the prism resting on the surface to be tested. By applying additional weights, this 20 contact with the surface to be measured can be intensified, in particular in the case of soft, elastic objects such as diapers, for example. Conversely, it is also possible to keep the applied weight as small as possible by inverting the prism such that the hypotenuse face comes to lie upwards, and the object to be measured is then placed on the hypotenuse surface.
The generation of pulsed light radiation can be performed in a mechanical way byinterrupting the light of a continuously operating light source by means of a mechanical chopper periodically at a known frequency. Electronically, such light can be generated by modulating the intensity of the light emitted by the light source at a 30 frequency prescribed from outside. It is likewise possible periodically to interrupt the light beam of a continuous source by means of an electro-optic component, for example, by means of a Pockels cell.
Owing to the use according to the invention of monochromatic light, pulsed lightsources, spectral filters and frequency-selective photoelectric transducers (10)and/or amplifiers, the device is insensitive to the incidence of extraneous light.
5 Lasers, for example helium neon lasers, or laser diodes are preferably used as light sources. The wavelength can be in the visible or infrared spectral region.
The device according to the invention is particularly suitable for examining hygiene articles such as, for example, baby diapers, incontinence diapers, sanitary napkins, 10 hospital bed undersheets, nonwovens and textile fabrics.
Surprisingly, it has been found that this measuring system can also be extended to technical applications. Thus, for example, it is also possible to examine technical two-dimensional absorbent materials in the case of which the surface moisture level 15 is caused not only by aqueous solutions but also by organic liquids such as, for example, isopropanol, ethanol or oils, such as, for example, paraffin oil, silicone oil and mineral oil.
Example 1 The surface moisture level of diapers was measured with and without incidence ofextraneous light. The light source used was a type LD 242 laser diode, which emits light of wavelength 880 nm at a power of 8 mW/sr. The radiation of the light source was modulated with a frequency taken 25 from a trigger generator. A type BPW 43 diode was used as photoelectric transducer. Its output signal was amplified by means of a frequency-selective amplifier into which the frequency of the trigger generator was fed as reference.
Table 1 shows the measurement results which were obtained without the incidence of extraneous light, as well as the results which where obtained with lateral 30 irradiation of the measuring device and of the diaper using a fluorescent lamp with a power of 11 W.
Table 1 Surface moisture level (%) Without extraneous light With extraneous light Comparative Example 10 The same measuring arrangement as in Example 1 was selected, but the light source and the detecting amplifier were not operated in the pulsed fashion. The measurement values obtained from the same measuring objects are shown in Table 2.
Table 2 Surface moisture level (%) Without extraneous light With extraneous light 25 ~ 35 The following Examples 2 and 3 describe other methods of generating light.
Example 2 A 12V/5W halogen lamp was used as light source. The emitted light was choppered mechanically at 9600 Hz by a slotted disc. The measurement signals were receivedby a BPY 47P silicon photoelectric cell and subsequently processed for 30 measurement purposes ina PC.
Example 3 A helium-neon laser of wavelength 632.8 nm was used as light source. The emittedlight was choppered mechanically at 9600 Hz by a slotted disc. The measured 5 signals were received by a BPW 21 photodiode, which has a measuring range of 350 - 820 nm and a sensitivity peak 550 nm, and subsequently processed metrologically in a PC.
Claims (10)
1. A device for determining the surface moisture level of sorptive or liquid-absorbing, two-dimensional structures and materials, essentially comprising a Dove inverting prism (1), a light source (2) which is arranged such that its parallel-directed light beams (2a) impinge perpendicularly on one of the short faces (3) of the prism (1) and are reflected by the hypotenuse face of the prism (1), which is brought into contact with the surface (9) to be measured with respect to moisture level, a light trap (4) which is arranged such that thebeams (2c) reflected by the hypotenuse face impinge on it, and a photoelectric transducer (10) which is located in the right angle formed by the two short faces (3) and (5) and arranged such that its measuring surface is situated opposite and parallel to the hypotenuse face of the prism, and which converts the light (2b) scattered by the surface (9) to be measured with respect to moisture level into a measuring signal, wherein a) the light used for the measurement has a known, fixed wavelength, and wherein a1) located upstream of the photoelectric transducer (10) is a filter which passes only this wavelength, or wherein a2) the photoelectric transducer (10) is sensitive only to this wavelength, or wherein b1) the light used for the measurement is pulsed, starting from its generation, at a known, fixed frequency or is pulsed by a suitable device, which is located in the light beam (2a) upstream of the entry into the prism (1), and wherein b2) the photoelectric transducer (10) is operated with selective sensitivity to the known fixed frequency, and wherein its output signal is amplified with selective sensitivity to this frequency, or wherein c) in a combination of both methods, light of a known, fixed wavelength and of a known, fixed frequency is used.
2. The device as claimed in claim 1, wherein the light source is a laser.
3. The device as claimed in claim 1, wherein the light source is a laser diode.
4. The device as claimed in claim 1, wherein the device suitable for periodic interruption of the light beam is a mechanical chopper.
5. The device as claimed in claim 1, wherein the device suitable for periodic interruption of the light beam is an electro-optic component.
6. Use of the device as claimed in claim 1 to determine the surface moisture level of sorptive or liquid-absorbing two-dimensional structures and materials.
7. Use of the device as claimed in claim 1 to determine the surface moisture level of hygiene articles or technical materials.
8. Use of the device as claimed in claim 1 to determine the surface moisture level of absorbent and filter materials, baby diapers, incontinence diapers, hospital bed undersheets and textiles.
9. Use of the device as claimed in claim 1 to determine surface moisture levelswhich are caused by water, aqueous solutions and fluid organic compounds.
10. Use of the device as claimed in claim 1 to determine surface moisture levelswhich are caused by isopropanol, ethanol or oils such as paraffin oil, silicone oil or mineral oil.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19614265.2 | 1996-04-11 | ||
| DE19614265A DE19614265A1 (en) | 1996-04-11 | 1996-04-11 | Device for determining the surface moisture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2202314A1 true CA2202314A1 (en) | 1997-10-11 |
Family
ID=7790960
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002202314A Abandoned CA2202314A1 (en) | 1996-04-11 | 1997-04-10 | Method for determining surface moisture level |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0801300A3 (en) |
| JP (1) | JPH10111239A (en) |
| CA (1) | CA2202314A1 (en) |
| DE (1) | DE19614265A1 (en) |
| HU (1) | HUP9700730A1 (en) |
| NO (1) | NO971638L (en) |
| PL (1) | PL319426A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019190544A1 (en) * | 2018-03-30 | 2019-10-03 | Hewlett-Packard Development Company, L.P. | Agents on print media |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3770352A (en) * | 1972-05-08 | 1973-11-06 | Philco Ford Corp | Totally reflecting laser refractometer |
| GB2158939B (en) * | 1984-05-15 | 1988-06-02 | Plessey Co Plc | Improvements relating to the detection and/or monitoring of surface conditions |
| US4704029A (en) * | 1985-12-26 | 1987-11-03 | Research Corporation | Blood glucose monitor |
| DE3735269A1 (en) * | 1987-10-17 | 1989-04-27 | Hoechst Ag | DEVICE FOR DETERMINING SURFACE HUMIDITY |
| FR2672127A1 (en) * | 1991-01-28 | 1992-07-31 | Arufog Assoc | Detector for the change in refractive index of a medium in contact with a transparent wall such as a windscreen or inspection window |
-
1996
- 1996-04-11 DE DE19614265A patent/DE19614265A1/en not_active Withdrawn
-
1997
- 1997-04-02 EP EP97105490A patent/EP0801300A3/en not_active Withdrawn
- 1997-04-09 HU HU9700730A patent/HUP9700730A1/en unknown
- 1997-04-10 CA CA002202314A patent/CA2202314A1/en not_active Abandoned
- 1997-04-10 JP JP9092457A patent/JPH10111239A/en not_active Withdrawn
- 1997-04-10 PL PL97319426A patent/PL319426A1/en unknown
- 1997-04-10 NO NO971638A patent/NO971638L/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| HU9700730D0 (en) | 1997-05-28 |
| NO971638D0 (en) | 1997-04-10 |
| MX9702688A (en) | 1998-06-28 |
| EP0801300A2 (en) | 1997-10-15 |
| NO971638L (en) | 1997-10-13 |
| EP0801300A3 (en) | 1998-03-11 |
| PL319426A1 (en) | 1997-10-13 |
| JPH10111239A (en) | 1998-04-28 |
| DE19614265A1 (en) | 1997-10-16 |
| HUP9700730A1 (en) | 1998-09-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6233470B1 (en) | Absorption information measuring method and apparatus of scattering medium | |
| US5318362A (en) | Non-contact techniques for measuring temperature of radiation-heated objects | |
| JP2780935B2 (en) | Method and apparatus for measuring concentration of absorption component of scattering absorber | |
| US20040075840A1 (en) | Optical amplification in coherent optical frequency modulated continuous wave reflectometry | |
| DE69219767D1 (en) | METHOD AND DEVICE FOR MONITORING THE GLUCOSE CONCENTRATION | |
| CN108061722A (en) | The detection device and detection method of a kind of carbonomonoxide concentration | |
| EP1069426B1 (en) | Method and device for measuring concentration of absorbing component of scattering/absorbing body | |
| CN110243729A (en) | Corpuscular counter | |
| JPH08178870A (en) | Spectroscopic method and device for measuring minute absorbing amount or reflecting amount of material sample | |
| TW201944055A (en) | Carrier lifespan measurement method and carrier lifespan measurement device | |
| JP4009442B2 (en) | Dynamic light scattering measurement system using low coherence interferometry | |
| CA2202314A1 (en) | Method for determining surface moisture level | |
| CN111727495B (en) | Concentration measuring method and concentration measuring device | |
| JP3065446B2 (en) | Ultrasonic vibration measurement method | |
| MXPA97002688A (en) | Device for determining humidity superfic | |
| JP2717600B2 (en) | Thin film evaluation equipment | |
| JPH1183812A (en) | Ultrasonic wave detecting method by laser beam and device therefor | |
| JPH05226445A (en) | Non-contact carrier diffusion length measuring device | |
| JP2513867B2 (en) | Voltage detector | |
| KR100588532B1 (en) | Apparatus of laser-ultrasonics measurement using reflective photo detector | |
| CN109238964A (en) | A kind of sensing device | |
| JPH07243965A (en) | Light absorption information detecting method for light scattering medium | |
| JPH11101741A (en) | Fiber liquid detector | |
| JPH03148005A (en) | Non-contacting surface roughness measuring apparatus for on-machine measurement | |
| SU1762194A1 (en) | Method for determination of threshold of optical products surface destruction |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |