WO2013186434A1 - A sensor and a method in connection with a sensor for harsh environment - Google Patents

A sensor and a method in connection with a sensor for harsh environment Download PDF

Info

Publication number
WO2013186434A1
WO2013186434A1 PCT/FI2013/050616 FI2013050616W WO2013186434A1 WO 2013186434 A1 WO2013186434 A1 WO 2013186434A1 FI 2013050616 W FI2013050616 W FI 2013050616W WO 2013186434 A1 WO2013186434 A1 WO 2013186434A1
Authority
WO
WIPO (PCT)
Prior art keywords
sensor
space
accordance
microchip
previous
Prior art date
Application number
PCT/FI2013/050616
Other languages
French (fr)
Inventor
Marko Jalonen
Original Assignee
Vaisala Oyj
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Vaisala Oyj filed Critical Vaisala Oyj
Publication of WO2013186434A1 publication Critical patent/WO2013186434A1/en

Links

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
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/85—Investigating moving fluids or granular solids
    • G01N21/8507—Probe photometers, i.e. with optical measuring part dipped into fluid sample
    • 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
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
    • 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
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
    • G01N21/3504—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
    • 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
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
    • G01N21/15—Preventing contamination of the components of the optical system or obstruction of the light path
    • G01N2021/151—Gas blown
    • 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
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
    • G01N21/15—Preventing contamination of the components of the optical system or obstruction of the light path
    • G01N2021/158—Eliminating condensation
    • 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
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/85—Investigating moving fluids or granular solids
    • G01N21/8507—Probe photometers, i.e. with optical measuring part dipped into fluid sample
    • G01N2021/8514—Probe photometers, i.e. with optical measuring part dipped into fluid sample with immersed mirror
    • G01N2021/8521—Probe photometers, i.e. with optical measuring part dipped into fluid sample with immersed mirror with a combination mirror cell-cuvette
    • 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
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/27—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection ; circuits for computing concentration
    • G01N21/274—Calibration, base line adjustment, drift correction
    • 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
    • G01N21/59—Transmissivity
    • G01N21/61—Non-dispersive gas analysers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/0004—Gaseous mixtures, e.g. polluted air
    • G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
    • G01N33/0027—General constructional details of gas analysers, e.g. portable test equipment concerning the detector
    • G01N33/0036—General constructional details of gas analysers, e.g. portable test equipment concerning the detector specially adapted to detect a particular component
    • G01N33/004—CO or CO2

Definitions

  • the invention relates to a sensor for harsh environment according to the preamble of claim 1.
  • the invention also relates to a method in connection with a sensor for harsh environment.
  • the sensors for harsh environment the entire sensor structure is within the harsh process space and vulnerable to humidity and process gases like C0 2 .
  • the prior art solution has been to create as tight a package as possible for the microchips used in the sensor.
  • Even the tightest packages with feed-thru connections or any connections can't prevent the penetration of humidity and gases into the package surrounding the sensor microchips and this causes multiple problems. Sealing the package increases also the manufacturing costs and the cost is proportional to the tightness.
  • Harsh process environments are very demanding for the sensor components and especially for the sensor microchips. E.g. in incubator solutions the temperature is around 37 °C and relative humidity around 95%.
  • the invention is based in forming the chip space of the sensor such that it is not sealed but arranged to be ventilated to a space isolated from the harsh process space.
  • the chip space is ventilated to a normal room space that is isolated from the harsh process space. Due to ventilation, the isolation in direction to the process space does not need to be even close to perfect. The ventilation takes place when the sensor is in normal measuring operation. More specifically, the sensor according to the invention is characterized by what is stated in the characterizing part of claim 1.
  • a stabile sensor structure that can tolerate high temperatures like 200 °C hot sterilizing cycles and high concentrations of humidity, C0 2 and other process gases and fluids, may be obtained cost efficiently.
  • the sensor elements like infra red emitter, infra red detector may be glued e.g. to the TO-base, in other words into the microchip space, which is ventilated into another space separated from the harsh process space.
  • the invention is easy to implement despite unconventional nature.
  • the microchip space is almost hermetical to the direction of the harsh process space but ventilated to the easier environment, typically a normal room space.
  • the ventilation takes place in the normal operation of the sensor.
  • the microchips may be protected from humidity and harmful process gases and fluids. Also harmful leakage of the gas to be measured or other harmful fluids for the measurement can be eliminated by the ventilation of the microchip space.
  • the invention also enables hot sterilization because the gases evaporated during sterilization can be removed by ventilation.
  • the ventilation hole enables calibration by a calibration gas of predetermined gas content or characterizing the sensor e.g. by adjusting the voltage of a tunable FPI 9 by absorption maximums or minimums of the calibration gas.
  • FIG. 2 shows one embodiment of an optical detector in accordance with the invention.
  • the following list indicates the used terms and the coiTesponding reference numerals: List of terms
  • the sensor microchips 8, 9 are protected within hermetically sealed packages (e.g. TO-package) in solutions, where the measurement is performed in harsh process environments 21.
  • the sensor element 1 typically includes a light source 4 and a detector 8 at the ends of an optical path 7.
  • a sensor 1 may also include a filter, typically a Fabry Perot Interferometer 9 in order to adjust the wavelength of measurement to the desired wavelength for the gas to be measured.
  • the adjustment can be made based on the physical properties of the FPI 9, like layer thicknesses or the FPI 9 may be electrically adjustable such that the length of the FPI 9 cavity may be adjusted by electrostatic forces, hence allowing calibration methods for the sensing element or even detecting of several gases of interest by scanning a broader wavelength area.
  • the principle of sensor 1 is to optically measure the content of at least one process gas (e.g. C0 2 ) by detecting the intensity of the light 4 in a narrow optical wave length band corresponding absorption maxima of the gas to be measured.
  • the measurement takes place on the optical path 7 between the light source and the detector 8 and the wavelength is selected by the FPI 9.
  • Sensor 1 is positioned inside the sensor frame 13, which extends from the process space 21 through the wall 30 into the ambient space 22.
  • Sensor 1 is connected by a cable 23 to the measurement electronics 20 positioned in the ambient room space 22.
  • sensor 1 is in the process environment, process space 21 , in this case in an incubator.
  • Process wall 30 separates the process space 21 from the normal "ambient" room space 22.
  • the environmental properties in an incubator solution are the following:
  • Process space 21 37°C, 95% RH, 5 % C0 2
  • Package 2 containing the microchips 8, 9 is not perfectly hermetical and the process gases leak 5 in. Because the optical path 7 also continues inside the package 2 into the microchip space 6, the leaked gas 5 in the case that it is the gas to be measured causes drift in the reading of the measurement device.
  • a solution is described for a C0 2 incubator in accordance with figure 2.
  • the invention is based on a tight enough structure 10 in direction of the process space 21 (like incubator) by e.g. a window sealing 10 but ventilated 16 well enough structure in direction to the space 22 separated from the process space 21 through ventilation hole 16 or multiple holes, which may have filter structures included.
  • the solution of figure 2 is implemented by an optical path 7 formed by a mirror 15 and with this solution both the IR-emitter 11 and the detector 12 may be positioned in the same microchip space 6.
  • the invention may be implemented also with the layout of figure 1.
  • the microchip space 6 may include also a Fabry Perot Interferometer as in figure 1.
  • the emitter 11 and detector 12 may be positioned also in their own packages, each having a ventilation hole 16 to the ambient space 22. Separation may be motivated in order to prevent optical, electrical or thermal cross coupling between the emitter 1 1 and the detector 12.
  • the microchip space 6 will not be contaminated by high humidity or high CO 2 or any other process gas concentration from the process space 21 , which solves the two first problems mentioned in connection with the prior art.
  • a sensor structure requiring hot sterilizing includes several microchips (micro emitter, FPI or other Band-Pass filters and IR-detector) to be glued to the sensor structure.
  • microchips micro emitter, FPI or other Band-Pass filters and IR-detector
  • the glue emits typically very high amounts of C0 2 and hydrocarbons into space 6 where microchips 11 and 12 are situated, but due to the ventilated 16 structure of the invention the CO 2 , hydrocarbons and humidity will be ventilated outside of sensor 1.
  • the invention also makes possible a calibration cycle, where the ventilation hole 16 is used for feeding a calibration gas into the microchip space 6. With a calibration gas with a predetermined amount of the gas to be measured the reading of the device may be calibrated accurately with this procedure.
  • the invention is applicable also to other sensor types, which might be disturbed by the harsh measurement space, e.g. easily corrodible sensors or sensors having water (H 2 0) as an error source.
  • the ventilation holes 16 typically have the following dimensions: In a microchip space with volume of 350 mm 3 a hole or holes having an area of 25 mm 2 is created.
  • the tightness of the window 10 sealing affects the need for the ventilation. The tighter the window sealing is, the less ventilation is needed and vice versa.
  • the ventilation hole 16 may be a single one or consist of several holes. Each hole 16 may have a filter for preventing particles entering the chip space 6. Referring to figure 1, ventilation may be implemented through the cable 23 such that the air flows within the cable jacket, which minimizes contamination of the microchip space 6.
  • microchip means a microchip processed in a clean environment, whereby the microchip includes process details in the micrometer scale.
  • the hole 16 is positioned on the back wall of the microchip space 6, however the hole or holes 16 can be also on the sidewalls (up, down or on the sides) of said space 6 provided that the frame 13 includes corresponding channels (not presented) extending to the ambient space 22.
  • microship space 6 means any space for sensitive components connected to the measurement electronics electronically or by
  • the normal operation of the sensor means any operational phase when it is used for measurement.
  • a sensor 1 When a sensor 1 is ready for use means in this application a sensor which is ready to perform measurements. This definition does not mean a sensor or part of it e.g. during a
  • the described embodiment of the invention is an optical measurement device using infra red wavelength.
  • the invention is applicable to all wavelength bands like ultraviolet spectrum.
  • the ventilation hole solution can be used in all kinds of sensors.

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)
  • Spectroscopy & Molecular Physics (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Measuring Temperature Or Quantity Of Heat (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

The invention relates to a sensor (1) and a method. The sensor structure includes microchips (8, 9, 11) positioned in a microchip space (6). In accordance with the invention the microchip space (6) includes at least one ventilation hole (16) in an operational phase of the sensor.

Description

A sensor and a method in connection with a sensor for harsh environment
The invention relates to a sensor for harsh environment according to the preamble of claim 1. The invention also relates to a method in connection with a sensor for harsh environment. The Prior Art
In the prior art the sensors for harsh environment the entire sensor structure is within the harsh process space and vulnerable to humidity and process gases like C02. The prior art solution has been to create as tight a package as possible for the microchips used in the sensor. However, even the tightest packages with feed-thru connections or any connections can't prevent the penetration of humidity and gases into the package surrounding the sensor microchips and this causes multiple problems. Sealing the package increases also the manufacturing costs and the cost is proportional to the tightness.
1 ) Harsh process environments are very demanding for the sensor components and especially for the sensor microchips. E.g. in incubator solutions the temperature is around 37 °C and relative humidity around 95%.
In addition, high humidity or other process chemicals may cause essential corrosion in microchips and also for this reason the microchips are packaged as hermetically as possible. However, the sealing is never perfect in practice and the package starts to leak at some point in time and as a result the humidity and chemical content is eventually the same inside the package as in the process space. This happens e.g. in incubator solutions within 6 - 12 months, typically.
2) Especially in incubators there is typically a continuous 5% concentration of C02. This concentration penetrates gradually (typically within 6- 12 months) into the microchip package of the sensor causing IR absorption inside the package and consequently causing noticeable drift upwards in the reading of the measuring device.
In optical sensors designed for high concentrations this is especially disadvantageous, because the active optical path on the process side is very short (in some solutions about 10 mm and the optical path inside the package (e.g. 1 mm ) causes essential drift in the reading of the device because the additional high C02 concentration (typically 5% C02) has penetrated the package. This in addition to humidity is one of the major causes of drift in C02 sensors. 3) There is a need especially in connection with C02 sensors used with incubators to hot sterilize (180-200°C) the measurement head. At present there is no solution for doing this sterilization, because the sensor components like IR-emitters do not endure the high temperatures and the glue materials used for microchips cause high C02 concentrations inside the packages. The C02 from the heated glue may cause very high drift upwards. Heating may also cause leakages in tight packages.
In the prior art there are also solutions where the chip space has been filled with an inert gas (US Pat. 13054251), however sealed later for actual use. Also in US Patent 5603892 a solution is presented where in the packaging phase the gas content of the microchip space is filled with a gas in a controlled manner, however, the microchip space is sealed for normal measurement use.
Invention
It is an object of the present invention to provide a novel type of sensor and method capable of overcoming at least some problems of the prior-art technology described above.
The invention is based in forming the chip space of the sensor such that it is not sealed but arranged to be ventilated to a space isolated from the harsh process space. In other words, in a typical implementation of the invention the chip space is ventilated to a normal room space that is isolated from the harsh process space. Due to ventilation, the isolation in direction to the process space does not need to be even close to perfect. The ventilation takes place when the sensor is in normal measuring operation. More specifically, the sensor according to the invention is characterized by what is stated in the characterizing part of claim 1.
Furthermore, the method according to the invention is characterized by what is stated in the characterizing part of claim 10. The invention offers significant benefits.
With the present invention a stabile sensor structure that can tolerate high temperatures like 200 °C hot sterilizing cycles and high concentrations of humidity, C02 and other process gases and fluids, may be obtained cost efficiently. The sensor elements like infra red emitter, infra red detector may be glued e.g. to the TO-base, in other words into the microchip space, which is ventilated into another space separated from the harsh process space.
The invention is easy to implement despite unconventional nature.
Attempts have been made to solve the above problems for years without any success, hence the solution in accordance with the invention cannot be obvious. Without the solution of the invention it is impossible to manufacture a cost efficient, stabile, in situ measurement head that enables hot sterilizing.
In the solution in accordance with the invention the microchip space is almost hermetical to the direction of the harsh process space but ventilated to the easier environment, typically a normal room space. The ventilation takes place in the normal operation of the sensor. By this structure the microchips may be protected from humidity and harmful process gases and fluids. Also harmful leakage of the gas to be measured or other harmful fluids for the measurement can be eliminated by the ventilation of the microchip space. The invention also enables hot sterilization because the gases evaporated during sterilization can be removed by ventilation. In addition the ventilation hole enables calibration by a calibration gas of predetermined gas content or characterizing the sensor e.g. by adjusting the voltage of a tunable FPI 9 by absorption maximums or minimums of the calibration gas.
In the following, the invention will be examined with the help of exemplifying embodiments illustrated in the appended drawings in which Figure 1 shows a prior art optical detector.
Figure 2 shows one embodiment of an optical detector in accordance with the invention. The following list indicates the used terms and the coiTesponding reference numerals: List of terms
1 Optical sensor
2 Microchip package
4 Light source
5 Gas leakage
6 Microchip space, space for sensitive components
7 Optical path
8 Detector
9 FPI, tunable or fixed Fabry Perot Interferometer, microchip
10 Window
1 1 IR-emitter, microchip
12 IR-detector, microchip
13 Sensor frame
15 Mirror
16 Ventilation hole
20 Electronics
21 Process space
22 Room space
23 Cable
30 Process wall In accordance with figure 1 in the prior art of optical sensors 1 the sensor microchips 8, 9 are protected within hermetically sealed packages (e.g. TO-package) in solutions, where the measurement is performed in harsh process environments 21. In the prior art the sensor element 1 typically includes a light source 4 and a detector 8 at the ends of an optical path 7. A sensor 1 may also include a filter, typically a Fabry Perot Interferometer 9 in order to adjust the wavelength of measurement to the desired wavelength for the gas to be measured.
The adjustment can be made based on the physical properties of the FPI 9, like layer thicknesses or the FPI 9 may be electrically adjustable such that the length of the FPI 9 cavity may be adjusted by electrostatic forces, hence allowing calibration methods for the sensing element or even detecting of several gases of interest by scanning a broader wavelength area.
The principle of sensor 1 is to optically measure the content of at least one process gas (e.g. C02) by detecting the intensity of the light 4 in a narrow optical wave length band corresponding absorption maxima of the gas to be measured. The measurement takes place on the optical path 7 between the light source and the detector 8 and the wavelength is selected by the FPI 9. Sensor 1 is positioned inside the sensor frame 13, which extends from the process space 21 through the wall 30 into the ambient space 22. Sensor 1 is connected by a cable 23 to the measurement electronics 20 positioned in the ambient room space 22.
In other words, referring to figure 1 , sensor 1 is in the process environment, process space 21 , in this case in an incubator. Process wall 30 separates the process space 21 from the normal "ambient" room space 22. As an example the environmental properties in an incubator solution are the following:
Process space 21 : 37°C, 95% RH, 5 % C02
Room space 22: 25°C, 50% RH 0.05 %C02
This causes various problems. Package 2 containing the microchips 8, 9 is not perfectly hermetical and the process gases leak 5 in. Because the optical path 7 also continues inside the package 2 into the microchip space 6, the leaked gas 5 in the case that it is the gas to be measured causes drift in the reading of the measurement device. As an example for one preferred embodiment of the invention a solution is described for a C02 incubator in accordance with figure 2.
Despite the new solution in accordance with then invention is simple to manufacture, it is not an obvious solution for the man skilled in the art. The invention is based on a tight enough structure 10 in direction of the process space 21 (like incubator) by e.g. a window sealing 10 but ventilated 16 well enough structure in direction to the space 22 separated from the process space 21 through ventilation hole 16 or multiple holes, which may have filter structures included.
The solution of figure 2 is implemented by an optical path 7 formed by a mirror 15 and with this solution both the IR-emitter 11 and the detector 12 may be positioned in the same microchip space 6. The invention may be implemented also with the layout of figure 1. The microchip space 6 may include also a Fabry Perot Interferometer as in figure 1.
The emitter 11 and detector 12 may be positioned also in their own packages, each having a ventilation hole 16 to the ambient space 22. Separation may be motivated in order to prevent optical, electrical or thermal cross coupling between the emitter 1 1 and the detector 12.
Due to the hole 16 the microchip space 6 will not be contaminated by high humidity or high CO2 or any other process gas concentration from the process space 21 , which solves the two first problems mentioned in connection with the prior art.
The structure in accordance with the invention solves also the third problem mentioned in connection with the prior art enabling hot sterilizing. Typically, a sensor structure requiring hot sterilizing includes several microchips (micro emitter, FPI or other Band-Pass filters and IR-detector) to be glued to the sensor structure. Unfortunately during hot sterilizing cycles (180-200°C) the glue emits typically very high amounts of C02 and hydrocarbons into space 6 where microchips 11 and 12 are situated, but due to the ventilated 16 structure of the invention the CO2 , hydrocarbons and humidity will be ventilated outside of sensor 1.
Without this ventilation the high amount of CO2 (or hydrocarbons) inside of the sensor 6 would cause high absorption in the optical path 7 inside the sensor package 6 and cause strong drift upwards of the reading of the CO2 (or hydrocarbon) sensor device. The invention also makes possible a calibration cycle, where the ventilation hole 16 is used for feeding a calibration gas into the microchip space 6. With a calibration gas with a predetermined amount of the gas to be measured the reading of the device may be calibrated accurately with this procedure.
Of course, the invention is applicable also to other sensor types, which might be disturbed by the harsh measurement space, e.g. easily corrodible sensors or sensors having water (H20) as an error source.
The ventilation holes 16 typically have the following dimensions: In a microchip space with volume of 350 mm3 a hole or holes having an area of 25 mm2 is created.
In the following considerations about the size of the holes 16:
The smaller the microchip space 6 is the more ventilation is needed in order to remove the disturbing gases away as fast as possible. On the other hand, the closer the microchips 11 and 12 are to the window 10 (which means typically smaller microchip space 6) the smaller the influence of the C02 gas in the microchip space 6 has on the measurement supposing that the microchip space 6 does not decrease. Therefore the need for ventilation is less and consequently the area of the holes may be smaller. Also the tightness of the window 10 sealing affects the need for the ventilation. The tighter the window sealing is, the less ventilation is needed and vice versa.
The ventilation hole 16 may be a single one or consist of several holes. Each hole 16 may have a filter for preventing particles entering the chip space 6. Referring to figure 1, ventilation may be implemented through the cable 23 such that the air flows within the cable jacket, which minimizes contamination of the microchip space 6. In this application microchip means a microchip processed in a clean environment, whereby the microchip includes process details in the micrometer scale.
In figure the hole 16 is positioned on the back wall of the microchip space 6, however the hole or holes 16 can be also on the sidewalls (up, down or on the sides) of said space 6 provided that the frame 13 includes corresponding channels (not presented) extending to the ambient space 22.
In this application the definition "microship space 6" means any space for sensitive components connected to the measurement electronics electronically or by
telecommunications.
The normal operation of the sensor means any operational phase when it is used for measurement.
When a sensor 1 is ready for use means in this application a sensor which is ready to perform measurements. This definition does not mean a sensor or part of it e.g. during a
manufacturing process taking place in a clean room, when the sensor or its parts are not ready for use.
The described embodiment of the invention is an optical measurement device using infra red wavelength. However, the invention is applicable to all wavelength bands like ultraviolet spectrum. The ventilation hole solution can be used in all kinds of sensors.

Claims

Claims:
1. A sensor (1) structure including microchips (8, 9, 11) positioned in at least one microchip space (6), characterized in that the at least one microchip space (6) includes at least one ventilation hole (16) when the sensor (1) is ready for use.
2. A sensor (1) structure in accordance with claim 1 positioned in a process space (21) for measuring properties from the process space (21) isolated from ambient space (22) by isolating means (30), characterized in that the microchip space (6) includes ventilation holes (16) opening to an ambient space (22) isolated from the process space (21).
3. A sensor (1) structure in accordance with claim 1 or 2, characterized in that it is an optical sensor.
4. A sensor (1) structure in accordance with any previous claim or their combination, characterized in that it is a NDIR-optical sensor for C02 measurement.
5. A sensor (1) structure in accordance with any previous claim or their combination, characterized in that the hole (16) is covered with filter material.
6. A sensor (1) structure in accordance with any previous claim or their combination, characterized in that the sensor includes an optical path (7) formed by a mirror (15).
7. A sensor (1) structure in accordance with any previous claim or their combination, characterized in that the microchips (1 1, 12) are positioned on a TO-base and the hole (16) is formed in the TO-base.
8. A sensor (1) structure in accordance with any previous claim or their combination, characterized in that the hole (16) or holes are formed on the sidewalls of the microchip space (6).
9. A sensor (1) structure in accordance with any previous claim or their combination, characterized in that the hole is formed in the back wall of the microchip space (6).
10. A method in connection with a sensor (1) structure including microchips (8, 9, 11) positioned in a microchip space (6), characterized in that the microchip space (6) is ventilated by at least one ventilation hole (16) when the sensor (1) is ready for use.
1 1. A method in accordance with claim 1 where the sensor (1) is positioned in a process space (21) for measuring properties from the process space (21) isolated from ambient space (22) by isolating means (30), characterized in that the microchip space (6) is equipped with ventilation holes (16) opening to an ambient space (22) isolated from the process space (21).
12. A method in accordance with any previous claim or their combination, characterized in that the sensor operates in NDIR-optical principle and is used for sensor C02 measurement in an incubator.
13. A method in accordance with any previous claim or their combination, characterized in covering the hole (16) with filter material.
14. A method in accordance with any previous claim or their combination, characterized in that an optical path (7) is formed by a mirror (15).
15. A method in accordance with any previous claim or their combination, characterized in that the microchips (11 , 12) are positioned on a TO-base and the hole (16) is formed in the TO-base.
16. A method in accordance with any previous claim or their combination, characterized in that the hole (16) or holes are formed on the sidewalls of the microchip space (6).
17. A method in accordance with any previous claim or their combination, characterized in that the hole is formed in the back wall of the microchip space (6).
18. A method in accordance with any previous claim or their combination, characterized in that the hole (16) is used for feeding calibration gas into the microchip space (6).
19. A method in accordance with any previous claim or their combination, characterized in that the hole (16) is used for characterizing of a tunable Fabry Perot Interferometer (9).
PCT/FI2013/050616 2012-06-15 2013-06-06 A sensor and a method in connection with a sensor for harsh environment WO2013186434A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI20125665 2012-06-15
FI20125665A FI20125665L (en) 2012-06-15 2012-06-15 Sensor and method in connection with a sensor intended for harsh conditions

Publications (1)

Publication Number Publication Date
WO2013186434A1 true WO2013186434A1 (en) 2013-12-19

Family

ID=49757638

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI2013/050616 WO2013186434A1 (en) 2012-06-15 2013-06-06 A sensor and a method in connection with a sensor for harsh environment

Country Status (2)

Country Link
FI (1) FI20125665L (en)
WO (1) WO2013186434A1 (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5747808A (en) * 1994-02-14 1998-05-05 Engelhard Sensor Technologies NDIR gas sensor
WO1998049539A1 (en) * 1997-04-30 1998-11-05 Honeywell Inc. Micromachined inferential opto-thermal gas sensor
JP2002328118A (en) * 2001-04-27 2002-11-15 Yamatake Corp Method of manufacturing gas diffusion filter for photoacoustic gas sensor
JP2003227794A (en) * 2002-02-04 2003-08-15 Riken Keiki Co Ltd Gas detector for incubator
DE10220668A1 (en) * 2002-05-10 2003-11-20 Technologie Nord Gmbh Incubation chamber has gas sensor with emitter and detectors co-located in thermally-protected chamber with side gas apertures
US20090135415A1 (en) * 2005-06-16 2009-05-28 Jeong-Ik Park Optical Cavity for Gas Sensor
US20110304844A1 (en) * 2010-06-15 2011-12-15 Bert Willing Gas sensor and process for measuring moisture and carbon dioxide concentration

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5747808A (en) * 1994-02-14 1998-05-05 Engelhard Sensor Technologies NDIR gas sensor
WO1998049539A1 (en) * 1997-04-30 1998-11-05 Honeywell Inc. Micromachined inferential opto-thermal gas sensor
JP2002328118A (en) * 2001-04-27 2002-11-15 Yamatake Corp Method of manufacturing gas diffusion filter for photoacoustic gas sensor
JP2003227794A (en) * 2002-02-04 2003-08-15 Riken Keiki Co Ltd Gas detector for incubator
DE10220668A1 (en) * 2002-05-10 2003-11-20 Technologie Nord Gmbh Incubation chamber has gas sensor with emitter and detectors co-located in thermally-protected chamber with side gas apertures
US20090135415A1 (en) * 2005-06-16 2009-05-28 Jeong-Ik Park Optical Cavity for Gas Sensor
US20110304844A1 (en) * 2010-06-15 2011-12-15 Bert Willing Gas sensor and process for measuring moisture and carbon dioxide concentration

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"AirTest Technologies, Infrared C02 Sensor For Incubation Applications.", MODEL DATASHEET, 20 August 2002 (2002-08-20), pages 1, Retrieved from the Internet <URL:http:/www.airtest.com/support/manual/TR95031ncubator.pdf> [retrieved on 20130207] *

Also Published As

Publication number Publication date
FI20125665L (en) 2013-12-16

Similar Documents

Publication Publication Date Title
EP2321052B1 (en) Device for exposing a sensor to a cell culture population in a bioreactor vessel
US7135342B2 (en) Electro-optical sensing device with reference channel
US10705044B2 (en) Inline sensor arrangement and method for commissioning same
US9234905B2 (en) Method of calibrating and calibration apparatus for a moisture concentration measurement apparatus
ES2099182T3 (en) ELECTROCHEMICAL SENSOR ASSEMBLY.
AU1431497A (en) Passive infrared analysis gas sensors and applicable multichannel detector assemblies
TW200846639A (en) System and method for non-intrusive thermal monitor
EP2362940A1 (en) Hybrid gas analyzer
JP2021508372A (en) Systems and methods for determining container health by optical measurements
WO2021170755A1 (en) System and method for determining the integrity of containers by optical measurement
CN103257125B (en) For measuring the method for CO2 content and the sensor of fluid
WO2013186434A1 (en) A sensor and a method in connection with a sensor for harsh environment
US11339416B2 (en) Inline sensor arrangement, and method for producing and commissioning said inline sensor arrangement
US10495619B2 (en) Device for determining a concentration of an analyte in a gaseous medium
US10288552B2 (en) Sealing arrangement and sealing method of a measuring device
EP4191231B1 (en) Particle sensor
US10627359B2 (en) Sensor platform including thermal conductivity sensor for analyzing the contents and surroundings of sealed packages or insulated glass units
KR101199941B1 (en) Crystal growth system for microgravity conditions
EP4421477A1 (en) Package for an optical radiation device
KR100285909B1 (en) Apparatus and method for analyzing water content by using near infrared of short wavelengths
WO2023107724A1 (en) Thermocouple leak detection
KR20230054126A (en) Transparent chamber for evaluating detectability of colloidal crystal-based colorimetric sensor, and testing device having the same
WO2020230070A1 (en) Method and apparatus for ascertaining the presence of cracks in sealed containers
Biermann et al. NDIR Gas Measurement in Harsh Environments by Advanced IR Components
WO2011062517A1 (en) Analytical system for determining components which exhibit circular dichroism in a sample under analysis, device for the arrangement of samples and optical diffusometer

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13803995

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13803995

Country of ref document: EP

Kind code of ref document: A1