SYSTEM FOR MONITORING AIR QUALITY IN AN ENCLOSED ENVIRONMENT

Abstract

In the field of monitoring air quality, and more specifically, the field of identification of the presence of gaseous chemical pollutants such as volatile organic compounds, in an enclosed environment, there is disclosed a system including: a substrate; a gaseous chemical pollutant sensor; and at least one colorimetric marker of a predetermined colour situated on the substrate.

Claims

1-49. (canceled)

50. System for identifying the presence of at least one gaseous chemical pollutant, preferably a volatile organic compound, in an enclosed environment, said system comprising: a substrate (1); a gaseous chemical pollutant sensor (2) rendered rigidly connected to the substrate (1); said sensor (2) changing colour according to the gaseous chemical pollutant concentration and the exposure time; and at least one colorimetric marker (5A, 5B, 5C, 5D, 5E) of a predetermined colour situated on the substrate.

51. System according to claim 50, wherein at least one colorimetric marker (5A, 5B, 5C, 5D, 5E) is of a colour corresponding to the colour of the sensor in the presence of at least one gaseous chemical pollutant, preferably in the presence of a volatile organic compound.

52. System according to claim 50, wherein at least one colorimetric marker (5A, 5B, 5C, 5D, 5E) is white in colour.

53. System according to claim 50, wherein at least one colorimetric marker (5A, 5B, 5C, 5D, 5E) is black in colour.

54. System according to claim 50, wherein at least one colorimetric marker (5A, 5B, 5C, 5D, 5E) is grey in colour.

55. System according to claim 50, wherein the system further comprises at least one bar-code (6), preferably situated on the substrate (1).

56. System according to claim 50, wherein the substrate (1) is parallelepipedal in shape, preferentially a rectangular parallelepiped.

57. System according to claim 50, wherein the system further comprises a moisture detector, preferably situated on the substrate (1).

58. System according to claim 50, wherein the system further comprises a temperature detector, preferably situated on the substrate (1).

59. System according to claim 50, wherein the system does not comprise a light source.

60. System according to claim 50, wherein the substrate (1) does not emit gaseous chemical pollutants.

61. System according to claim 50, wherein the system further comprises a mobile application or an electronic chip.

62. System according to claim 61, wherein the mobile application or the electronic chip comprises at least one database, suitable for use for determining the colour of the sensor and for determining the concentration of the gaseous chemical pollutant in the enclosed environment in question.

63. System according to claim 50, wherein the system further comprises optical recording means suitable for obtaining an image of the sensor (2) or of the assembly formed by the sensor (2) and the substrate (1) thereof.

64. System according to claim 50, wherein the system further comprises at least one display or transmission means.

65. System according to claim 50, wherein the gaseous chemical pollutant is a volatile organic compound (VOC), preferably an aldehyde; more preferentially formaldehyde.

66. System according to claim 50, wherein the sensor (2) comprises a nanoporous specific absorbent material functionalised with at least one probe molecule capable of reacting in the presence of the gaseous chemical pollutant; preferably capable of reacting in the presence of a volatile organic compound.

67. System according to claim 66, wherein the probe molecule is chosen among enaminones and -diketone/amine pairs, imines and hydrazines, or salts derived from these compounds.

68. System according to claim 50, wherein the sensor comprises an absorbent material obtained by a sol-gel process.

69. System according to claim 50, wherein the sensor comprises a parallelepipedal-shaped absorbent material.

70. Process for determining a concentration level of a gaseous chemical pollutant, preferably a volatile organic compound, in an enclosed environment, implementing a system according to claim 50, comprising the following steps: a. analysing a first optical recording of the substrate comprising the sensor; b. analysing a second optical recording of the same substrate comprising the sensor on expiration of a time t; c. comparing between the first and the second optical recording; d. computing a colorimetric distance; e. analysing said colorimetric distance with reference to a database and determining the concentration of the gaseous chemical pollutant in the enclosed environment; and optionally f. displaying or transmitting the concentration of the gaseous chemical pollutant in the enclosed environment.

71. Process according to claim 70, wherein the step for analysing a first optical recording of the substrate (1) comprising the sensor (2) and the step for analysing a second optical recording of the same substrate (1) comprising the sensor (2) on expiration of a time t comprise a calibration step according to the ambient brightness, preferably a step for setting the white balance, contrast and/or colour quality.

72. Method for using the system according to claim 50, with a view to determining the concentration of a gaseous chemical pollutant, preferably a volatile organic compound, in an enclosed environment, comprising the following steps: a. providing the substrate (1) comprising the sensor (2) and, if applicable, the moisture detector; b. placing the substrate (1) comprising the sensor (2) in the enclosed environment to be measured; c. carrying out a first optical recording of the substrate (1) comprising the sensor (2); d. carrying out a second optical recording of the substrate (1) comprising the sensor (2), on expiration of a time t; e. determining the concentration level of the gaseous chemical pollutant by performing steps of: i. analysing a first optical recording of the substrate comprising the sensor; ii. analysing a second optical recording of the same substrate comprising the sensor on expiration of a time t; iii. comparing between the first and the second optical recording; iv. computing a colorimetric distance; v. analysing said colorimetric distance with reference to a database and determining the concentration of the gaseous chemical pollutant in the enclosed environment; and optionally vi. displaying or transmitting the concentration of the gaseous chemical pollutant in the enclosed environment.

73. Packaging comprising at least one system according to claim 50, said packaging being impervious to moisture, light and/or gases.

74. Onboard system comprising a device, such as a ventilation or air purification device, wherein is rigidly mounted at least one system according to claim 50.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0219] FIG. 1 is a top view of the system according to the invention.

[0220] FIG. 2 illustrates the onboard sensor according to the invention.

LISTS OF REFERENCES

[0221] 1Substrate;

[0222] 2Sensor;

[0223] 3Central square;

[0224] 4Rectangle;

[0225] 5A, 5B, 5C, 5D, 5EColorimetric marker square;

[0226] 6QR Code;

[0227] 7White LED;

[0228] 8Red Green Blue sensor;

[0229] 9Protective film;

[0230] 10White surface;

[0231] 11Protective mask against interferences.

EXAMPLES

[0232] The present invention will be understood more clearly on reading the following examples which illustrate the invention in a non-limiting manner.

Example 1: Target Card

[0233] FIG. 1 shows an embodiment of the invention wherein a substrate 1 bears a sensor 2, which is a functionalised nanoporous specific absorbent material. The substrate 1 is a card type substrate. The sensor 2 is positioned on this substrate 1 in a central square 3 comprising at the centre thereof a rectangle 4 delimiting a zone intended to receive the sensor 2. The sensor 2 is secured by bonding, with an adhesive not releasing VOCs, for example a cyanhydric adhesive.

[0234] The substrate further comprises four square-shaped colorimetric markers 5A, 5B, 5C, 5D of different colours: for example, a yellow square (represented by the hatched square), a white square, a grey square and a black square, the order of positioning whereof is of no importance.

[0235] The sensor 2 is a formaldehyde sensor which changes in a range of yellows and at least one of the squares 5A, 5B, 5C, 5D is of Pantone yellow colour for the purposes of evaluating the change in the colour of the sensor with an unchanging control in the colour range. The white, grey and black squares serve to adjust the real colour temperature i.e. recalibrate the colour to remove differences due to the optical recorder or to the lighting.

[0236] The substrate 1 further comprises a QR code 6 which serves to identify the sensor on a unit basis, and particularly to identify the sensor in the database.

[0237] Advantageously, the squares 5A, 5B, 5C, 5D and the QR code 6 are positioned on the substrate 1 such that they make it possible to make a correction of the geometry of the image capture, if required. Indeed, during image capture, an angle may be formed between the optical recording means and the card involving a slight modification of the dimensions of the card.

[0238] Advantageously, the substrate further comprises one or a plurality of further squares 5E which are positioned with respect to the squares 5A, 5B, 5C, 5D and to the QR code 6 such that they make it possible to evaluate a possible inclination during image capture.

Example 2: Example of Use of the Card

[0239] The user purchases a card, which is supplied in nitrogen wrapping. Instructions for use are supplied with the card. In the instructions, it is specified that the card must be used in relation with a smartphone and a moisture detector, and the user is requested to download the mobile application. The instructions specify to the user that a photo must be taken within a few minutes following the exposure of the card to ambient air, preferably from 5 to 90 minutes after opening the packaging. The image capture conditions are specified in the instructions. To optimise image capture, it is advisable to choose a time of the day when there is satisfactory brightness for the photo, and place the target next to a window without direct sunlight. It is furthermore necessary not to use a flash so as to prevent overexposure. Indeed, exposure to a flash or to a light source involve spatial inhomogeneity of the lighting.

[0240] Firstly, the user tests the moisture of the enclosed environment wherein the VOC concentration is measured. The application is set to photo mode and the user takes a photo of the target.

[0241] The application checks whether the photo is of poor quality or not, i.e. whether it is too out of focus, not straight enough, with colours that are too dark, with colours that are too light, incorrect colours. If such is the case, the application may request to repeat the capture operation of the initial photo which is a reference photo. Then, the application notifies that you will be contacted within 24 hrs to take the final photo and complete the test.

[0242] Secondly, after 24 hrs, the application requests the visible estimation on the moisture detector then, requests that a second, final photo be taken, under the same conditions as the first photo.

[0243] The application computes the pollutant on the basis of the two photos.

[0244] The application will seek to determine the parameters liable to impact the results such as the temperature of the enclosed environment, the environmental pressure, the fixtures and fittings and age, the room volume, the presence of ventilation, the number of doors, windows and among the number, those which are open.

Example 3: Onboard System

[0245] FIG. 2 illustrates an onboard system according to the invention. The onboard system comprises a device, particularly in a reader, a ventilation device or an air purification device, a substrate 1 comprising a sensor 2, a white LED 7 illuminating the sensor 2 and a Red Green Blue sensor 8 to capture the light of the sensor 2. The onboard system also comprises a protective film 9 separating the white LED 7 from the Red Green Blue sensor 8, so as to prevent direct exposure of the Red Green Blue sensor 8. The onboard system further comprises a white surface 10 to the rear of the substrate 1 and a protective mask against interferences 11.