WO2022185311A1

WO2022185311A1 - Systems and methods for monitoring fluid of a fluid facility having an inspection subsystem for inspection of light sources used in the monitoring system

Info

Publication number: WO2022185311A1
Application number: PCT/IL2022/050233
Authority: WO
Inventors: Alexander RACHMAN; Shahar SOBOL; Hanoch Kislev; Avner RICHARD; Igor Lulko
Original assignee: Maytronics Ltd.
Priority date: 2021-03-04
Filing date: 2022-03-02
Publication date: 2022-09-09

Abstract

Systems and methods for monitoring and inspection of a fluid facility such as water from a swimming pool facility configured to: receive updated MLS data, indicative of optical characteristics associated with light emanating from a main light source (MLS); receive updated RLS data, indicative of optical characteristics associated with light emanating from a reference light source (RLS), the MLS and the RLS having similar optical characteristics; analyze the received updated MLS and RLS data to identify changes in optical characteristics of MLS data; determine whether detected changes in optical characteristics of the MLS data require performing at least one mitigation action; and perform at least one mitigation action when such is determined to be required.

Description

SYSTEMS AND METHODS FOR MONITORING FLUID OF A FLUID FACILITY HAVING AN

INSPECTION SUBSYSTEM FOR INSPECTION OF LIGHT SOURCES USED IN THE

MONITORING SYSTEM

FIELD OF THE INVENTION

[0001] The present invention generally relates to systems, subsystems, devices and methods for measuring optical characteristics of light sources and more particularly to systems, subsystems, devices and methods for inspection and automatic adjustments of light sources that are utilized in monitoring systems for monitoring fluid in a fluid facility such as a swimming pool.

BACKGROUND

[0002] Constant-intensity-light sources are highly essential in optical sensing systems used in various applications including medical, environmental, and industrial applications, since the light intensity stability directly affects the reliability and accuracy of measurement results.

BRIEF DESCRIPTION OF THE FIGURES

[0003] The figures generally illustrate various embodiments of aspects of the present invention.

[0004] Components, elements, subsystems and/or designs shown in the following figures are not necessarily shown in a precise scale and/or proportions and may be used for schematic illustration of the general configuration and function of the illustrated system, subsystem, element and/or device.

[0005] The figures are listed as follows:

[0006] Fig. 1 shows at least part of a monitoring system for monitoring water quality in a water facility such as a swimming pool, having a main light source and an optical spectral detector, and an optical inspection subsystem for inspecting optical characteristics of the light source, the inspection subsystem including an additional reference light source, according to some embodiments;

[0007] Fig. 2 illustrates a schematic block diagram of modules of a processing and control unit of a monitoring system having an inspection subsystem therein, according to some embodiments;

[0008] Fig. 3 shows an exploded view of at least part of the optical layout of a monitoring system for monitoring fluid quality in a fluid facility such as a swimming pool, having an optical inspection subsystem embedded within the monitoring system, according to some embodiments;

[0009] Fig. 4 is a flowchart schematically illustrating a process of inspection of a main light source and/or spectral detector performances, using a reference light source, according to some embodiments; and

[00010] Fig. 5 is a flowchart schematically illustrating a process of ongoing fluid monitoring and light sources inspection, using the monitoring system having an inspection subsystem embedded therein, according to some embodiments

DETAILED DESCRIPTION

[00011] Aspects of disclosed embodiments, pertain to inspection of optical characteristics of one or more light sources utilized in monitoring systems, for monitoring one or more attributes (such as physical, chemical and/or biological attributes) of a fluid in a fluid facility, such as, for example, a swimming pool fluid. The fluid monitoring may be based at least on optical sensing or optical detection, e.g. based on spectroscopy/spectrometry of the fluid or a sample thereof. The monitoring may require using one or more controlled intensity light sources for emission of light, e.g. within a narrow or limited optical wavelength/frequency range such as within part of the ultraviolet (UV) and/or visible (VIS) and/or infrared (IR) spectral range, for optical-based detection of the one or more physical/chemical/biological attributes of the fluid, e.g. for detection of pollutants and/or measurement of concentration of chemical and/or biological substance.

[00012] Commonly used controlled intensity light sources may still exhibit temporary or permanent reduction of emission intensity or emission intensity stability over time, which may affect fluid's monitoring reliability. Intensity stability of e.g. constant or pulsed light sources may be influenced by various inner and/or external causes such as, for example, power supply changes and instability, light source hardware wear-out, environmental obstructions and/or influences such as temperature changes and the like.

[00013] It is noted that the term "light source", or "controlled intensity light source" used herein may relate to any device, system and/or instrument configured for emission of light, whether a spectrally /broad light source or a light source emitting within one or more specific wavelength/frequency bands within the optical spectrum,. A light source may include one or more lamps such as arc lamps and/or light emitting diodes (LEDs) of one or more output wavelengths.

[00014] The term "intensity stability" may relate to stability and/or sensitivity of any one or more of the following optical characteristics of light emitted from any type of a light source: intensity, amplitude, optical output power/energy/flux; intensity/amplitude of each separate wavelength/frequency; and/or each wavelength/frequency band of the light source, and the like.

[00015] The terms "intensity", "amplitude", "optical output power/energy/flux" may be used interchangeably herein, based on mathematical and/or physical relations therebetween.

[00016] The intensity stability may be influenced by one or more influencers such as temperature, temperature change rate (severe drop or increase), consecutive operation duration of the light source, pressure, medium in which the light source is placed in, etc. [00017] In some cases, optical characteristics of light sources may change, drift or deteriorate over time. For example, the light source may exhibit spectral drifts causing spectrum peaks and/or absorption lines to drift and/or smear, reducing accuracy of spectroscopy data, making it practically impossible to deduce the attributes of the monitored fluid based on the spectroscopy data over time, unless a proper correction is performed.

[00018] Temperature changes/values may also influence performances of the optical detector(s) being used for measuring, such as spectral drifts (or shifts), changes in absorption lines widths, in measured spectrum of the light source or of a sample through which light of the light source is directed (where the spectral detector is located to measure light emanating from the sample being illuminated by the light source), for example, when using a spectrometer as the optical detector.

[00019] Aspects of disclosed embodiments pertain to systems and methods for monitoring a fluid from a fluid facility such as a swimming pool water sample, configured to perform at least the following steps:

[00020] receive and analyze data from the at least one monitoring optical detector to determine one or more updated attributes of the fluid from the fluid facility;

[00021] control operation of the MLS and of the RLS;

[00022] receive updated MLS data, indicative of optical characteristics of the MLS (where the updated MLS data is acquired by use of one or more optical detectors directly detecting light emanating from the MLS or light emanating from a fluid sample illuminated by the MLS);

[00023] receive updated RLS data, indicative of optical characteristics of the RLS (where the updated RLS data is acquired by use of one or more optical detectors directly detecting light emanating from the RLS or light emanating from a fluid sample illuminated by the RLS);

[00024] analyze the received updated MLS and RLS data to identify changes in optical characteristics of the MLS; [00025] determine whether detected changes in optical characteristics of the MLS require performing a mitigation action; and

[00026] perform at least one determined mitigation action when such is determined to be required for mitigating identified changes in MLS optical characteristics.

[00027] According to some embodiments, the processing and control unit may determine whether identified changes in optical characteristics are caused due malfunctioning of the MLS (e.g., deterioration of functioning or spectral drifts caused due to temperature decrease/increase in the MLS vicinity) and/or due to malfunctioning of the spectral detector (such as spectral drifts caused due to temperature decrease/increase in the vicinity of the spectral detector) causing changes/errors in the output spectrum, outputted from the detector. The mitigation of any of the spectral drifts may be adjustment of analysis of the spectral detector's output data (e.g., by correcting wavelengths drifts by peaks/absorption lines corrected value adjustments) and/or by replacement of the MLS (e.g. by the RLS) if only the MLS is found to be malfunctioned such that will require its replacement.

[00028] According to some embodiments, detected/determined spectral drifts of the MLS or of the optical detector output may require and be associated with mitigation actions involving adjustment of one or more analysis models used for analysis/processing of output data from the optical detector (e.g. spectrometer), disabling the system for a specific cooling/heating period and/or replacement of the MLS by using the RLS instead.

[00029] Aspects of disclosed embodiments pertain to systems for monitoring one or more attributes of a fluid in a facility that contains or channels the fluid, include:

[00030] at least a main light source (MLS);

[00031] a reference light source (RLS);

[00032] a first optical spectral detector;

[00033] a second optical detector; [00034] a cuvette configured to contain therein a sampled fluid of the respective fluid facility;

[00035] one or more optical elements configured and arranged such as to direct light from the MLS and from the RLS towards to first optical spectral detector, via the cuvette and towards the second optical detector; and a processing and control unit.

[00036] The processing and control unit may be configured to: measure optical characteristics of the MLS using the first and/or the second optical detector, acquiring thereby updated MLS data; separately measure optical characteristics of the RLS using and/or the second optical detector, analyze the acquired updated MLS and RLS data, which may be related to each other and/or to historical/accumulated MLS and RLS data, to identify changes in optical characteristics of the MLS; and initiate a mitigation procedure (performance of one or more mitigation actions) for mitigating the MLS performances changes and/or for mitigating the process of monitoring of attributes of the fluid of the respective fluid facility, the mitigation procedure being based on identified changes in MLS optical characteristics.

[00037] According to some embodiments, the mitigation action(s) may include, for example, one or more of: replacing the MLS; replacing the MLS by the RLS; adjusting one or more factors of a spectral analysis model (SAM), based on the identified changes in optical characteristics of the MLS, the SAM being configured to analyze output data of the at least one monitoring optical detector; heating or cooling of the MLS; disabling the system for a cooling/heating period and re-measuring MLS performances, etc.

[00038] Aspects of embodiments pertain to methods for monitoring one or more attributes of a fluid in a facility that contains the fluid therein, the methods may include:

[00039] providing a monitoring subsystem comprising a monitoring optical setup, configured for optically measuring one or more attributes of a fluid from a fluid facility such as a swimming pool, the monitoring optical setup may include at least one main light source (MLS) and at least one monitoring optical (spectral) detector such as a spectrometer;

[00040] providing an inspection subsystem, comprising an inspection optical setup comprising at least one reference light source (RLS) and at least one inspection optical detector such as a photodetector (photodiode) for measuring optical characteristics of the MLS and/or of the RLS;

[00041] receiving updated MLS data acquired by the monitoring and/or by the inspection subsystems, the updated MLS data being indicative of optical characteristics of the MLS (e.g. spectrum thereof);

[00042] receiving updated RLS data acquired by the monitoring and/or by the inspection subsystems, the updated RLS data being indicative of optical characteristics of the RLS;

[0004S] analyzing the received updated MLS and RLS data to identify changes in optical characteristics of the MLS such as spectral drift, indicative, for example of deterioration of the MLS intensity stability; and

[00044] adjusting one or more factors of a spectral analysis model (SAM), based on the identified MLS impairments or changes, the SAM being configured to analyze output data of the at least one monitoring optical spectral detector e.g. adjusting an algorithm or a process, according to which the optical spectral detector output signal/data is analyzed during the fluid monitoring. This may allow mitigating the fluid attributes' identification/detection/calculation process by compensating the MLS changing/deteriorating optical characteristics at the software and/or hardware level of the processing (instead of replacing the MLS).

[00045] Additionally or alternatively the MLS may be controllable and/or adjustable such as to enable correcting at least some of the identified optical changes via MLS control/adjustment means, e.g., by changing the duration, intensity, frequency and/or electrical excitation characteristics of some or all of the light sources. [00046] Additionally or alternatively, upon identification of MLS optical characteristics changes that are determined as "fatal" e.g. changes indicative of severe MLS impairments that require urgent replacement of the MLS (e.g. based on predefined and/or programable criteria), the processing and control unit of the system may be configured to automatically provide alerts to one or more users and/or to automatically use the RLS (which may be of the same type) as a temporary replacement to the MLS.

[00047] In some embodiments, as mentioned above, the inspection of the MLS may be carried out by using a photodetector such as a UV photodiode, outputting output signals that can be used to calculate the updated overall intensity/amplitude/power/energy of the MLS (e.g. within a narrow wavelengths range such as within the UV range) by using the following equation:

[00049] Where E_w, is the updated MLS energy; E_w0, is the initial or optimal energy of the working light source; , P_w> represents an updated optical detector readout; and P_wQ represents an initial/optimal/approved optical detector readout.

[00050] In some cases, the MLS spectrum varies non- uniformly during its service lifetime. Thus, having the real-time light source spectrum reading may be critical for conducting a sensitive spectral analysis of multiple species, such as chemometric analysis for pool water probing. In some cases, a second spectrometer may be used for spectrum reconstruction. However due to cost issues, an optical system with a single spectrometer is often preferred.

[00051] According to some embodiments, an initial calibration process may be required, in order to measure the optimal/initial optical characteristics of the MLS, to enable identification of changes in its optical characteristics not only in relation to an additional RLS but also in comparison with the MLS initial/optimal state, for example, to also be able to verify whether the analysis of the output data originating from the monitoring optical spectral detector (e.g. spectrometer) used for fluid monitoring, should be adjusted and/or to physically adjust the optical elements layout.

[00052] According to some embodiments, the RLS may be of the same type (e.g. same lamp type, resulting in similar emission characteristics such as similar emission spectrum, power, etc.) as the MLS for enabling detecting related characteristics of the MLS by comparing equivalent parameters values/characteristics of similar/same light sources.

[0005S] The term "attributes" of the fluid may relate to any characteristics of such as chemical, biological and/or physical. For example, in case of a monitoring system configured for monitoring a swimming pool fluid quality related attributes, the measured attributes may include measuring chemical and/or biological components presence, quantity and/or concentration in the fluid e.g. by using spectrometry of the fluid.

[00054] The components that may be detectable via the monitoring subsystem may include, for example, levels of desirable chemical properties and/or various water chemical and/or biological contaminators or pollutants such as metallic and/or dust particles, algae, mold or scum growth, toxic chemical components, etc.), where the identification and concentration/quantity measurement/monitoring of those components is enabled based on optically detectable attributes of the monitored substances, and optical spectral detector capabilities based on the MLS spectral and intensity characteristics.

[00055] According to some embodiments, the monitoring of the fluid's attributes (e.g. fluid quality monitoring) may be carried out in a much more frequent manner than the frequency in which the inspection of the MLS is being performed.

[00056] For example, the monitoring frequency f_m0n may be between a few minutes to a few seconds, whereas the MLS inspection frequency fj_ns may be substantially lower (e.g. every few hours, days, weeks, etc.) depending on system requirements, environmental conditions (such as weather, season, temperature, etc.) and/or fluid facility and fluid specific characteristics (size of the swimming pool, water volume, updated (current) number of bathers inside the pool, average number of visitors etc. type and concentration of components used for the maintenance of the facility such as Chlorine consumption etc.).

[00057] According to some embodiments, an inspection may be carried out in a frequent (e.g. changeable prescheduled) manner, however the system may still allow sudden unscheduled inspection events upon identification of an event requiring an off- schedule inspection, e.g. based on one or more "inspection requirement criteria", such as a sudden drop/increase in temperature measurements, a sudden change in spectrometric analysis results, activation by technician, etc.

[00058] Embodiments pertain to a monitoring system for monitoring fluid quality of a fluid facility such as for a swimming pool that includes an inspection subsystem embedded therein. The inspection subsystem may include a RLS and an optical setup including one or more optical elements and at least one optical detector (such as a UV photodiode and/or a spectrometer), where the optical element(s) of the inspection optical setup is/are configured to direct the MLS and/or the RLS emitted light, towards the at least one optical detector of the inspection optical setup for measuring one or more optical characteristics of the MLS/RLS.

[00059] The monitoring system may also include a monitoring subsystem comprising another (monitoring) optical setup for optically measuring the one or more attributes of the swimming pool (SP) fluid. The monitoring optical setup may include, for instance, a cuvette, for holding therein a SP fluid sample and an optical spectral detector for optically measuring the one or more attributes of the SP fluid sample by conducting frequent spectral analysis of the fluid sample, for monitoring thereof.

[00060] According to some embodiments, in cases in which the fluid facility is a SP, for instance, the cuvette of the monitoring optical setup or the entire monitoring subsystem/system may be located such as to continuously or occasionally receive therein sample of the SP fluid. For example, the monitoring system may be located within an SP cleaning robot or along the SP piping. [00061] According to some embodiments, additional sensors (whether optical or non- optical sensors) may be used for fluid monitoring and/or for MLS inspection.

[00062] According to some embodiments, the MLS and/or the RLS includes at least one lamp, which may be for example, a light emitting diode (LED) lamp; ultraviolet (UV) LED lamp, Xenon lamp, etc., where the at least one lamp may be controllably operable in one or more pulsed modes. Alternatively, the lamp may be continuously emitting light.

[00063] In some embodiments, the spectrum of the MLS can be reconstructed (e.g. based on measured updated MLS and RLS data) using Eqn. 2 offll SrwW

[00064] (2) 5_W(A) = 5_W0(A)

SroWJ -¾w(¾J 1

[00065] Where S_W[X) is the reconstructed source emission spectrum; S_ro is the initial/optimal RLS spectra, S_wo is the initial/optimal MLS spectra, S_Ww is the MLS spectrum emitted from the fluid towards the optical spectral detector, and_, S_rw is the RLS spectrum emitted from the fluid towards the optical spectral detector. The MLS spectra may be accurately reconstructed, regardless of the non-uniform emission spectrum modification during service lifetime of the MLS, provided that the RLS spectra remains virtually constant (due to its low use).

[00066] In some embodiments, S_w0 S_r0 of the initial/optimal spectra of the MLS and

RLS, respectively, may be sampled and stored during a pre-calibration process of the monitoring and inspection system.

[00067] Reference is now made to Fig. 1, schematically illustrating a system 1000 for monitoring fluid of a fluid facility, the system 1000 having an illumination subsystem 1100, a monitoring subsystem 1200, a processing and control unit 1500 and an inspection subsystem comprising a RLS 1102 (which may be part of the illumination subsystem 1100) and may use the same optical elements and/or detection devices or a separate optical detector, according to some embodiments. [00068] The monitoring subsystem 1200 may include; a cuvette 1210; a focusing lens 1204; and an optical spectral detector 1220. The monitoring subsystem 1200 may also include one or more turbidity measurement device 1230.

[00069] The cuvette 1210 may be any fluid containing instruments and may have transparent walls for allowing light to pass therethrough.

[00070] The illumination subsystem 1100 may include: a MLS 1101; a RLS 1102, a first directing optical element 1105a such as a beam splitter or a prism; an optical mixing element 1103, e.g. configured for guiding therethrough light within a specific wavelength range (such as specific range within the UV or IR range); a second directing element 1105b such as a beam splitter or a prism; and an optical detector 1106 such as a UV/IR photodiode.

[00071] According to some embodiments, the system 1000 may be configured to use each light source 1101/1102 at different times (not simultaneously), such that in order to conduct a MLS 1101 inspection, the processing and control unit 1500 may be required to controllably switch between those light sources, in order to separately measure an updated MLS data and an updated RLS data.

[00072] The MLS 1101 and the RLS 1102 may be located in proximity to one another emitting light in different angular trajectories. Therefore, the first directing element 1105a may be used to enable optical directing of any of the light sources (whether the MLS or the RLS) 1101/1102 being used at a given measurement session (e.g. for inspection or for monitoring), towards and through the same optical elements defining thereby an optical pathway.

[00073] The length of the optical pathway for light emitted from the MLS "L_MLS" may not necessarily be equal to the length of the optical path of light emitted from the RLS

LRLS .

[00074] The optical pathway in these embodiments may be as follows: the emitted MLS/RLS light is passed through the first directing element 1105a and directed thereby towards the mixing element 1103. The mixing element may be configured to change/modify some of the optical characteristics of light entering therein and output mixing element output light (exiting from the mixing element 1103) e.g. of a linear filament propagation, and further directs light outputted therefrom through an optical aperture 1301 and a collimator 1302 (e.g. collimation lens) through the second directing element 1105b. The second directing element 1105b is designed to split the light outputted by the mixing element 1103 such as to direct a first portion thereof towards the photodiode 1106 to be detected thereby, and a second portion thereof through the cuvette 1210, which contains therein a sample of the fluid. The light outputted from the cuvette 1210 is then further directed (e.g. through the focusing lens 1204) towards the optical spectral detector 1220.

[00075] The configuration and layout of the optical components of the system 1000, allow ongoing (e.g. frequent) monitoring of the fluid sample in the cuvette 1210 using spectral analysis as well as occasional inspection of the MLS optical characteristics using the photodiode 1106 output analysis and optionally also optical spectral detector 1220 output analysis, without changing the optics and settings of the system 1000 components.

[00076] To enable the same result of enabling to direct each of the RLS/MLS light towards the inspection optical detector (photodiode 1106) as well as through the cuvette 1210 towards the optical spectral detector 1220 other optical layouts and components may be used (not shown).

[00077] According to some embodiments, the processing and control unit 1500 may be configured to receive output data/signals from the optical spectral detector 1220 and from the photodiode 1106 and process the received data for MLS inspection and for ongoing monitoring of the fluid.

[00078] Two separate processing models (e.g. software and/or hardware-based analysis processes) may be used:

[00079] a spectral analysis model (SAM) used during the fluid monitoring, the SAM being configured to analyze MLS data (e.g. arriving only from the optical spectral detector 1220) to detect one or more attributes of the sampled fluid using spectroscopy-based analytics; and

[00080] an inspection model (IM), configured to analyze received updated MLS and RLS data from the optical spectral detector and from the photodiode to identify changes in optical characteristics of the MLS and determine one or more SAM factors to be modified.

[00081] A SAM factor may be defined as a value of a parameter, coefficient, etc. that is used in the SAM algorithm/operator.

[00082] Once the SAM factors are determined the SAM is modified accordingly, adapting, thereby, the analysis of the optical spectral detector 1220 output to the updated spectral state of the MLS.

[0008B] Reference is now made to Fig. 2, schematically illustrating modules of the processing and control unit 1500, according to some embodiments. The processing and control unit 1500 may include:

[00084] a communication module 1510 configured, for example, for receiving and transmitting data from and to the optical detectors 1220/1106, transmit data (signals) to the MLS 1101, the RLS 1102 (e.g. for controlling thereof), communication with one or more remote communication devices, and the like.

[00085] an analysis module 1520 e.g. using the SAM an IM models for analyzing data arriving from the optical detectors 1220/1106 for fluid monitoring as well as for MLS inspection;

[00086] a control module 1530 configured, for example, for controlling the light sources 1101/1102 e.g. for switching therebetween for the MLS inspection process, and/or for adjusting one or more MLS 1201 control parameters/features (if the MLS enables such controlling), based on updated MLS and RLS data analysis results (e.g. the analysis being performed using the IM). The control module 1530 may be further configured to enable electronically controllable mechanical positioning and arrangement of the optical elements of the system 1000 (e.g. for enabling controllable and adjustable optical alignment of the optical elements etc.);

[00087] an alert module 1540 configured for: (i) determining alerting situations (e.g. based on IM and/or SAM analysis results indicative, respectively, of an MLS alerting state requiring MLS replacement for example, and/or indicative of a fluid monitoring alerting situation such as severe water pollution, dangerous fluid pH level, etc.); and (ii) transmitting alerts to one or more remote communication devices; where the control module 1530 may be configured to control one or more fluid facility maintenance devices and systems for mitigating the alerting fluid state (e.g. by adding more water and/or by adding chemical substances that help reduce pollution and/or adjust pH level etc. to the fluid facility, by heating or cooling the facility etc.);

[00088] a calibration module 1550 configured for enabling pre-calibration processes such as calibration of initial IM and/or SAM parameters;

[00089] a data storage 1560 for retrievably storing system related data such as updated analysis results, calibration data, IM and SAM programs and algorithms etc., specific fluid facility related data, facility maintenance and control related data and the like.

[00090] The processing and control unit 1500 may be implementable via any one or more types of hardware and/or software means such as, for example, by using an integrated circuit(s), a computerized device(s), etc.

[00091] According to some embodiments, the processing and control unit 1500 may include or be communicative with one or more input and/or display devices for enabling users to input and view information associated with the system 1000.

[00092] According to some embodiments, the system 1000 may require conducting a calibration process, for calibrating SAM and IM parameters, coefficients values, factors etc.

[00093] In some embodiments, the absorption spectrum A(l) of the fluid within the cuvette of the monitoring subsystem may be calculated according to Eqn. 3

[00095] Where S_pw is the transmission spectrum of the sampled water, and S_ddw is the reference spectrum of Double Distilled Water (DDW) i.e. using fluid of optimal limpidness.

[00096] According to some embodiments the system 1000 may further include an optical sub-system 1230 for measuring turbidity level of the fluid sample in the cuvette 1210 and/or for measuring the concentration of algae in the fluid, and the absorption A(l) may be corrected using the measured turbidity data.

[00097] Reference is now made to Fig. 3, schematically illustrating optical components of a system 100 for monitoring fluid of a fluid facility that has a light source inspection subsystem embedded therein, according to some embodiments.

[00098] The system 100 may include: a MLS 101, a RLS 102, a beam splitter 104, a mixing element 106 such as a mixing slab a prism 112 (e.g. pick-up prism), a light guide 122 such as an optical fiber or a set of reflectors, for directing portion of the light divided by the prism 112 towards an optical detector 114 such as a photodiode, and a monitoring functional unit 119 including a cuvette 120 for containing therein a fluid sample, and another optical detector 118 such as an optical spectral detector.

[00099] The layout and functioning of system 100 are similar to the layout and functioning of system 1000.

[000100] In some cases, the sample fluid in the cuvette 120 exhibits an excessive absorption (e.g. due to high fluid turbidity) often within a certain spectral range, such the deep UV band. In such cases, a portion of the nominator and denominator spectra in Eqn. 2 weakens and often becomes noisy. In turn, the SAM used for spectrally analyzing the detector output, may be modified by correcting Eqn. 2.

[000101] In some embodiments, the spectrally dependent ratio vector of Eqn. 2 can be smoothed and calibrated by Eqn. 4:

[000103] where _{w, r} are the MLS and RLS power respectively, as sampled by the optical spectral detector 118. Such smoothing and calibration minimizes inaccuracies of MLS reconstructed emission spectrum (e.g. via SAM modification).

[000104] As seen in Fig. 3, the MLS 101 and the RLS 102 are positioned at a predefined geometry to induce near-similar flux at the entrance to mixing element 106.

[000105] According to some embodiments, the mixing element 106 significantly blurs the spatial distribution properties of the MLS and the RLS.

[000106] Reference is now made to Fig. 4 illustrating a process of inspecting a MLS used in a fluid monitoring system (e.g. a monitoring system similar in main functionality and configuration as described above), according to some embodiments. The inspection process may include:

[000107] for each MLS inspection session:

[000108] acquiring updated MLS data by measuring one or more optical characteristics associated with the MLS, using one or more optical detectors (e.g. using the photodiode and/or the optical spectral detector output 41;

[000109] switching to RLS e.g. at a pre-defined frequency (once every few hours, days or weeks), or on demand, if required by detection of MLS deterioration using an optical detector (e.g. by controllably turning the MLS off and the RLS on) 42;

[000110] acquiring updated RLS data by measuring one or more optical characteristics of the RLS, using one or more optical detectors (e.g. using the photodiode and/or the optical spectral detector output) 43;

[000111] receiving the updated MLS and RLS data 44;

[000112] analyzing the received updated MLS and RLS data, e.g. by comparing them to one another and/or to historical/accumulated data, to identify one or more changes or malfunctions of the MLS and/or of the performance of the spectral detector 45; [000113] determining one or more mitigation actions for mitigating identified malfunctions or changes (if such action(s) is/are required) 46, such as adjustment of the SAM for mitigating spectral drifts of the MLS and/or of the spectrometer output46;

[000114] automatically jDTiiperforming determined and required one or more mitigation actions47; and

[000115] storing/outputting/sending analysis results and/or mitigation actions48.

[000116] Reference is now made to Fig. 5, schematically illustrating a process of monitoring a fluid of a fluid facility that incorporates inspection of a MLS that is used in the monitoring system, according to some embodiments. The monitoring process may include:

[000117] directing light emitted by the MLS through two optical setups (an inspection optical setup and a monitoring optical setup) for obtaining updated MLS data 51;

[000118] receiving output(s) from the monitoring optical spectral detector and optionally also from the inspection optical detector (e.g. photodiode) 52;

[000119] analyzing the received detector(s) output(s) (e.g. using a SAM) to determine one or more physical/chemical/biological attributes of the fluid sample 53;

[000120] upon identification of a requirement to conduct MLS inspection 54 e.g. based on several optional criteria such as : time for prescheduled frequent inspection, identification of MLS or fluid sample severe problem requiring a verification for the MLS functioning (for inspecting SAM accuracy and/or sensitivity), etc., switching the working light source from the MLS to the RLS 55, for initiating the inspection procedure;

[000121] once steps 51-52 are repeated 56 by using the RLS, RLS related detector(s) output(s) as well as most recently updated MLS related detector(s) output(s) can be analyzed 57 to determine changes in MLS optical characteristics;

[000122] if there are no significant or alarming changes in the MLS optical characteristics (e.g., if MLS performances are approved, optimal or workable) the system may revert to its fluid monitoring mode, if there are changes requiring MLS changes mitigation 58, a mitigation procedure may be activated 59, involving one or more of the following mitigation options: SAM modification based on calculated SAM factors using the identified MLS optical characteristics changes, MLS control, MLS replacement (e.g. by switching to RLS for utilizing it for the ongoing fluid monitoring or by replacement with a new MLS).

[00012S] The mitigation procedure may include selecting a mitigation option out of the predefined mitigation options according to the severity of the updated measured MLS optical characteristics and/or changes thereof. For example, less severe MLS functioning may only require adjusting the SAM for allowing reasonable spectrometry based monitoring of the fluid, whereas more severe MLS functioning (such as complete malfunctioning of the MLS) or drastic drop in overall intensity) may require replacement of the MLS.

[000124] According to some embodiments, the first optical setup, configured for directing light from each light source MLS/RLS that is operated, towards the inspection optical detector and towards the monitoring subsystem, may be configured in many other alternative manners in respect to those described in Fig. land Fig. 3. For example, one or more optical waveguides (e.g. one or more optical fibers) for each light source, may be used instead of the mixing element and optionally other additional optical elements, for splitting light emanating from each light source and for directing the light towards the additional optical detector (e.g. photodiode) and towards the monitoring optical spectral detector via the cuvette (e.g. two optical fibers, each guiding light from a different light source, and one or more beam splitters or pick-up prisms located at the output end of each optical fiber for splitting the guided light from the MLS/RLS to reach the two optical detectors).

[000125] EXAMPLES

[000126] Example 1 is a system for monitoring one or more attributes of a fluid from a fluid facility, the system comprising at least:

[000127] a monitoring subsystem comprising a monitoring optical setup, configured to optically measure one or more attributes of a fluid from the fluid facility, the monitoring optical setup comprising at least one main light source (MLS) and at least one optical detector, the MLS having expected MLS spectral characteristics;

[000128] an inspection subsystem, comprising an inspection optical setup comprising at least one reference light source (RLS), the RLS having expected RLS spectral characteristics that are similar to the expected MLS spectral characteristics; and

[000129] a processing and control unit configured at least to:

[000130] receive and analyze data from the at least one optical detector to determine one or more updated attributes of the fluid from the fluid facility;

[000131] control operation of the MLS and of the RLS;

[000132] receive updated MLS data, indicative of optical characteristics associated with light emanating from the MLS;

[000133] receive updated RLS data, indicative of optical characteristics associated with light emanating from the RLS;

[000134] analyze the received updated MLS and RLS data to identify changes in optical characteristics of MLS data;

[000135] determine whether detected changes in optical characteristics of the MLS data require performing a mitigation action; and

[000136] perform at least one determined mitigation action when such is determined to be required.

[000137] In example 2, the subject matter of example 1 may include, wherein the mitigation actions performable by the system comprise one or more of:

[000138] replacing the MLS;

[000139] replacing the MLS by the RLS;

[000140] adjusting one or more factors of a spectral analysis model (SAM), based on the identified changes in MLS data, the SAM being configured at least to analyze output data of the at least one optical detector; [000141] heating or cooling of the MLS;

[000142] disabling the MLS and or the at least one optical detector for a cooling/heating period.

[00014S] In example S, the subject matter of any one or more of examples 1 to 2 may include an inspection optical setup that further comprises at least one inspection optical detector configured and positioned to detect light directly emanating from one or more of the MLS and RLS.

[000144] In example 4, the subject matter of example S may include, wherein the at least one optical detector of the monitoring subsystem comprises at least one spectral detector.

[000145] In example 5, the subject matter of any one or more of examples 1 to S may include, wherein the at least one inspection optical detector of the inspection subsystem comprises at least one of: photodetector, photodiode, ultraviolet (UV) photodiode, infrared (IR) photodiode.

[000146] In example 6, the subject matter of any one or more of examples 1 to 5 may include, wherein the processing and control unit is configured to perform an ongoing or periodic inspection of the MLS for identification of malfunction in optical performances of the MLS and/or malfunctioning of the at least one optical detector of the monitoring subsystem, wherein the mitigation action required is determined based on identified malfunction.

[000147] In example 7, the subject matter of example 6 may include, wherein the malfunctions identifiable by the processing and control unit are based on identified changes in MLS optical characteristics, which comprise one or more of:

[000148] changes in intensity stability of the MLS;

[000149] changes, decrease or drop in output intensity, energy, power amplitude peak, and/or flux of the MLS light;

[000150] drifts in spectrum of the MLS light. [000151] In example 8, the subject matter of example 7 may include, wherein the decrease or drop in output intensity, energy, power amplitude peak, and/or flux of the MSL light is checked for one or more specific predefined spectral ranges and/or for an overall intensity, energy, power, amplitude peak and/or flux of the MLS light.

[000152] In example 9, the subject matter of any one or more of examples 6 to 8 may include, wherein the inspection of the functioning characteristics of the MLS is performed at an inspection frequency that is lower than a monitoring frequency at which the fluid is being monitored.

[000153] In example 10, the subject matter of any one or more of examples 6 to 9 may include, wherein the changes in optical characteristics of the MLS data are identifiable by comparing spectral characteristics of the received updated MLS data to a corresponding MLS initial, known, expected, previous and/or optimal spectral characteristics.

[000154] In example 11, the subject matter of any one or more of examples 1 to 9 may include, wherein the system further comprises at least one optical element, configured and positioned to direct light from each of the MLS and RLS towards a fluid sample, sampled from the fluid facility.

[000155] In example 12, the subject matter of any one or more of examples 1 to 11 may include, wherein the processing and control unit is configured to control operation of the MLs and of the RLS by enabling controllably switching on and off each of the MLS and RLS, wherein measurements are acquired for monitoring of the fluid facility by using one of the MLS or RLS, and wherein measurements acquired for obtaining updated MLS data are done by only operating the MLS and measurements acquired for obtaining updated RLS data are done by only operating the RLS, by controllable switching of the MLS and RLS.

[000156] In example 13, the subject matter of any one or more of examples 1 to 12 may include, wherein the MLS and RLS are configured to emit light within the same spectral range and/or at the same wavelength peak. [000157] In example 14, the subject matter of example 13 may include, wherein the MLS and RLS are configured to emit light within the infrared (IR) and/or the visible (VIS) and/or the ultraviolet (UV) spectral range.

[000158] In example 15, the subject matter of any one or more of examples 1 to 14 may include, wherein the monitoring subsystem is configured for ongoing measuring of fluorescence and/or scattered light emanating from a fluid sample, sampled from the fluid facility.

[000159] In example 16, the subject matter of example 15 may include, wherein the monitoring subsystem and processing and control unit are further configured to determine updated value of one or more of: concentration of one or more chemical and/or biological substances; fluid hardness; fluid turbidity level.

[000160] Example 17 is a method for monitoring one or more attributes of a fluid from a fluid facility, the method comprising at least:

[000161] providing at least one main light source (MLS) and at least one reference light source (RLS) having similar spectral characteristics;

[000162] receiving and analyzing data from at least one optical detector configured and positioned to measure optical characteristics of fluid of the fluid facility, when illuminated by one of the MLS or RLS, to determine one or more updated attributes of the fluid from the fluid facility;

[000163] controlling operation of the MLS and of the RLS;

[000164] acquiring updated MLS data, indicative of optical characteristics associated with light emanating from the MLS;

[000165] acquiring updated RLS data, indicative of optical characteristics associated with light emanating from the RLS;

[000166] analyzing the acquired updated MLS and RLS data to identify changes in optical characteristics of MLS data; [000167] determining whether detected changes in optical characteristics of the MLS data require performing at least one mitigation action; and

[000168] performing at least one determined mitigation action when such is determined to be required.

[000169] In example 18, the subject matter of example 17 may include, wherein the mitigation actions comprise one or more of:

[000170] replacing the MLS;

[000171] replacing the MLS by the RLS;

[000172] adjusting one or more factors of a spectral analysis model (SAM), based on the identified changes MLS data, the SAM being configured at least to analyze output data of the at least one optical detector;

[00017B] heating or cooling of the MLS;

[000174] disabling the MLS and or the at least one optical detector for a cooling/heating period.

[000175] In example 19, the subject matter of any one or more of examples 17 to 18 may include, wherein the method further comprises detecting light directly emanating from one or more of the MLS and RLS for obtainment of the updated MLS and RLS data.

[000176] In example 20, the subject matter of any one or more of examples 17 to 19 may include, wherein the method further comprises performing an ongoing or periodic inspection of the MLS for identification of malfunction or change in optical performances of the MLS and/or malfunctions in optical performances of the at least one optical detector, wherein the mitigation action required is determined based on identified malfunction or change.

[000177] In example 21, the subject matter of example 20 may include, wherein the malfunctions that are identifiable are based on identified changes in MLS optical characteristics, which comprise one or more of:

[000178] changes in intensity stability of the MLS; [000179] changes, decrease or drop in output intensity, energy, power amplitude peak, and/or flux of the MSL light;

[000180] drifts in spectrum of the MLS light.

[000181] In example 22, the subject matter of example 21 may include, wherein the decrease or drop in output intensity, energy, power amplitude peak, and/or flux of the MSL light is checked for one or more specific predefined spectral ranges and/or for an overall intensity, energy, power, amplitude peak and/or flux of the MLS light.

[000182] In example 23, the subject matter of any one or more of examples 21 to 22 may include, wherein the inspection of the functioning characteristics of the MLS is performed at an inspection frequency that is lower than a monitoring frequency at which the fluid is being monitored.

[000183] In example 24, the subject matter of any one or more of examples 21 to 23 may include, wherein the changes in optical characteristics of the MLS data are identifiable by comparing spectral characteristics of the received updated MLS data to a corresponding MLS initial, known, expected, previous and/or optimal spectral characteristics.

[000184] In example 25, the subject matter of any one or more of examples 17 to 24 may include, wherein the method further comprises directing light from each of the MLS and RLS towards a fluid sample, sampled from the fluid facility, by use of at least one optical element.

[000185] In example 26, the subject matter of any one or more of examples 17 to 25 may include, wherein the controlling of the operation of the MLs and of the RLS is done by controllably switching on and off each of the MLS and RLS, wherein measurements are acquired for monitoring of the fluid facility by using one of the MLS or RLS, and wherein measurements acquired for obtaining updated MLS data are done by only operating the MLS and measurements acquired for obtaining updated RLS data are done by only operating the RLS, by controllable switching of the MLS and RLS. [000186] In example 27, the subject matter of any one or more of examples 17 to 26 may include, wherein the MLS and RLS are configured to emit light within the same spectral range and/or at the same wavelength peak.

[000187] In example 28, the subject matter of example 27 may include, wherein the MLS and RLS are configured to emit light within the infrared (IR) and/or visible (VIS) and/or the ultraviolet (UV) spectral range.

[000188] In example 29, the subject matter of any one or more of examples 17 to 28 may include, wherein the method further comprises ongoing measuring of fluorescence and/or scattered light emanating from a fluid sample, sampled from the fluid facility.

[000189] In example 30, the subject matter of example 29 may include, wherein the method further comprises determining of an updated value of one or more of: concentration of one or more chemical and/or biological substances; fluid hardness; fluid turbidity level.

[000190] Example 31 is a system for monitoring one or more attributes of a fluid from a fluid facility, the system comprising at least:

[000191] (i) a cuvette for containing therein a fluid sample, sampled from the fluid facility;

[000192] (ii) at least one main light source (MLS);

[000193] (iii) at least one reference light source (RLS);

[000194] (iv) a spectral detector;

[000195] (v) an inspection optical detector;

[000196] (vi) one or more optical elements configured and arranged such as to direct light from the MLS towards the cuvette and towards the inspection optical detector and the RLS at least towards the inspection optical detector; and

[000197] (vii) a processing and control unit configured at least to:

[000198] control operation of the MLS and of the RLS; [000199] receive updated MLS data, indicative of optical characteristics associated with light emanating from the MLS;

[000200] receive updated RLS data, indicative of optical characteristics associated with light emanating from the RLS;

[000201] analyze the received updated MLS and RLS data to identify changes in optical characteristics of MLS data;

[000202] determine whether detected changes in optical characteristics of the MLS data require performing at least one mitigation action; and

[00020S] perform at least one determined mitigation action when such is determined to be required.

[000204] Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the invention as defined by the following invention and its various embodiments and/or by the following claims. For example, notwithstanding the fact that the elements of a claim are set forth below in a certain combination, it must be expressly understood that the invention includes other combinations of fewer, more or different elements, which are disclosed in above even when not initially claimed in such combinations. A teaching that two elements are combined in a claimed combination is further to be understood as also allowing for a claimed combination in which the two elements are not combined with each other, but may be used alone or combined in other combinations. The excision of any disclosed element of the invention is explicitly contemplated as within the scope of the invention.

[000205] The words used in this specification to describe the invention and its various embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification structure, material or acts beyond the scope of the commonly defined meanings. Thus, if an element can be understood in the context of this specification as including more than one meaning, then its use in a claim must be understood as being generic to all possible meanings supported by the specification and by the word itself.

[000206] The definitions of the words or elements of the following claims are, therefore, defined in this specification to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the claims below or that a single element may be substituted for two or more elements in a claim. Although elements may be described above as acting in certain combinations and even initially claimed as such, it is to be expressly understood that one or more elements from a claimed combination can in some cases be excised from the combination and that the claimed combination may be directed to a sub-combination or variation of a sub-combination.

[000207] Although the invention has been described in detail, nevertheless changes and modifications, which do not depart from the teachings of the present invention, will be evident to those skilled in the art. Such changes and modifications are deemed to come within the purview of the present invention and the appended claims.

Claims

CLAIMS What is claimed is:

1. A system for monitoring one or more attributes of a fluid from a fluid facility, the system comprising at least:

- a monitoring subsystem comprising a monitoring optical setup, configured to optically measure one or more attributes of a fluid from the fluid facility, the monitoring optical setup comprising at least one main light source (MLS) and at least one optical detector, the MLS having expected MLS spectral characteristics;

- an inspection subsystem, comprising an inspection optical setup comprising at least one reference light source (RLS), the RLS having expected RLS spectral characteristics that are similar to expected MLS spectral characteristics; and

- a processing and control unit configured at least to: receive and analyze data from the at least one optical detector to determine one or more updated attributes of the fluid from the fluid facility; control operation of the MLS and of the RLS; receive updated MLS data, indicative of optical characteristics associated with light emanating from the MLS; receive updated RLS data, indicative of optical characteristics associated with light emanating from the RLS; analyze the received updated MLS and RLS data to identify changes in optical characteristics of MLS data; determine whether detected changes in optical characteristics of the MLS data require performing a mitigation action; and perform at least one determined mitigation action when such is determined to be required.

2. The system of claim 1, wherein the mitigation actions performable by the system comprise one or more of: replacing the MLS; replacing the MLS by operating the RLS; adjusting one or more factors of a spectral analysis model (SAM), based on the identified changes MLS data, the ISAM being configured at least to analyze output data of the at least one optical detector; heating or cooling of the MLS; disabling the MLS and or the at least one optical detector for a cooling/heating period.

3. The system of any one or more of claims 1 to 2, wherein the inspection optical setup further comprises at least one inspection optical detector configured and positioned to detect light directly emanating from one or more of the MLS and RLS.

4. The system of claim 3, wherein the at least one optical detector of the monitoring subsystem comprises at least one spectral detector.

5. The system of any one or more of claims 1 to 3, wherein the at least one inspection optical detector of the inspection subsystem comprises at least one of: photodetector, photodiode, ultraviolet (UV) photodiode, infrared (IR) photodiode.

6. The system of any one or more of claims 1 to 5, wherein the processing and control unit is configured to perform an ongoing or periodic inspection of the MLS for identification of malfunction or change in characteristics in optical performances of the MLS and/or malfunctioning or change in characteristics of the at least one optical detector of the monitoring subsystem, wherein the mitigation action required is determined based on identified malfunction.

7. The system of claim 6, wherein the malfunctions or change in characteristics of optical performances, identifiable by the processing and control unit are based on identified changes in MLS optical characteristics, which comprise one or more of: changes in intensity stability of the MLS; changes, decrease or drop in output intensity, energy, power amplitude peak, and/or flux of the MSL light; drifts in spectrum of the MLS light.

8. The system of claim 7, wherein the decrease or drop in output intensity, energy, power amplitude peak, and/or flux of the MSL light is checked for one or more specific predefined spectral ranges and/or for an overall intensity, energy, power, amplitude peak and/or flux of the MLS light.

9. The system of any one or more of claims 6 to 8, wherein the inspection of the functioning characteristics of the MLS is performed at an inspection frequency that is lower than a monitoring frequency at which the fluid is being monitored.

10. The system of any one or more of claims 6 to 9, wherein the changes in optical characteristics of the MLS data are identifiable by comparing spectral characteristics of the received updated MLS data to a corresponding MLS initial, known, expected, previous and/or optimal spectral characteristics.

11. The system of any one or more of claims 1 to 10 further comprising at least one optical element, configured and positioned to direct light from each of the MLS and RLS towards a fluid sample, sampled from the fluid facility.

12. The system of any one or more of claims 1 to 11, wherein the processing and control unit is configured to control operation of the MLs and of the RLS by enabling controllably switching on and off each of the MLS and RLS, wherein measurements are acquired for monitoring of the fluid facility by using one of the MLS or RLS, and wherein measurements acquired for obtaining updated MLS data are done by only operating the MLS and measurements acquired for obtaining updated RLS data are done by only operating the RLS, by controllable switching of the MLS and RLS.

13. The system of any one or more of claims 1 to 12, wherein the MLS and RLS are configured to emit light within the same spectral range and/or at the same wavelength peak.

14. The system of claim 13, wherein the MLS and RLS are configured to emit light within the infrared (IR) and/or visible (VIS) and/or the ultraviolet (UV) spectral range.

15. The system of any one or more of claims 1 to 14, wherein the monitoring subsystem is configured for ongoing measuring of fluorescence and/or scattered light emanating from a fluid sample, sampled from the fluid facility.

16. The system of claim 15, wherein the monitoring subsystem and processing and control unit are further configured to determine updated value of one or more of: concentration of one or more chemical and/or biological substances; fluid hardness; fluid turbidity level.

17. A method for monitoring one or more attributes of a fluid from a fluid facility, the method comprising at least: providing at least one main light source (MLS) and at least one reference light source (RLS) having similar spectral characteristics; receiving and analyzing data from at least one optical detector configured and positioned to measure optical characteristics of fluid of the fluid facility, when illuminated by one of the MLS or RLS, to determine one or more updated attributes of the fluid from the fluid facility; controlling operation of the MLS and of the RLS; acquiring updated MLS data, indicative of optical characteristics associated with light emanating from the MLS; acquiring updated RLS data, indicative of optical characteristics associated with light emanating from the RLS; analyzing the acquired updated MLS and RLS data to identify changes in optical characteristics of MLS data; determining whether detected changes in optical characteristics of the MLS data require performing at least one mitigation action; and performing at least one determined mitigation action when such is determined to be required.

18. The method of claim 17, wherein the mitigation actions comprise one or more of: replacing the MLS; replacing the MLS by the RLS; adjusting one or more factors of a spectral analysis model (SAM), based on the identified changes MLS data, the SAM being configured at least to analyze output data of the at least one optical detector; heating or cooling of the MLS; disabling the MLS and or the at least one optical detector for a cooling/heating period.

19. The method of any one or more of claims 17 to 18, further comprising detecting light directly emanating from one or more of the MLS and RLS for obtainment of the updated MLS and RLS data.

20. The method of any one or more of claims 17 to 19 further comprising performing an ongoing or periodic inspection of the MLS for identification of malfunction or changes in optical performances of the MLS and/or malfunctions or changes in optical performances of the at least one optical detector, wherein the mitigation action required is determined based on identified malfunction.

21. The method of claim 20, wherein the malfunctions that are identifiable are based on identified changes in MLS optical characteristics, which comprise one or more changes in intensity stability of the MLS; changes, decrease, increase, rise or drop in output intensity, energy, power amplitude peak, and/or flux of the MLS light; drifts in spectrum of the MLS light.

22. The method of claim 21, wherein the decrease or drop in output intensity, energy, power amplitude peak, and/or flux of the MLS light is checked for one or more specific predefined spectral ranges and/or for an overall intensity, energy, power, amplitude peak and/or flux of the MLS light.

23. The method of any one or more of claims 21 to 22, wherein the inspection of the functioning characteristics of the MLS is performed at an inspection frequency that is lower than a monitoring frequency at which the fluid is being monitored.

24. The method of any one or more of claims 21 to 23, wherein the changes in optical characteristics of the MLS data are identifiable by comparing spectral characteristics of the received updated MLS data to a corresponding MLS initial, known, expected, previous and/or optimal spectral characteristics.

25. The method of any one or more of claims 17 to 24 further comprising directing light from each of the MLS and RLS towards a fluid sample, sampled from the fluid facility, by use of at least one optical element.

26. The method of any one or more of claims 17 to 25, wherein the controlling of the operation of the MLs and of the RLS is done by controllably switching on and off each of the MLS and RLS, wherein measurements are acquired for monitoring of the fluid facility by using one of the MLS or RLS, and wherein measurements acquired for obtaining updated MLS data are done by only operating the MLS and measurements acquired for obtaining updated RLS data are done by only operating the RLS, by controllable switching of the MLS and RLS.

27. The method of any one or more of claims 17to 26, wherein the MLS and RLS are configured to emit light within the same spectral range and/or at the same wavelength peak.

28. The method of claim 27, wherein the MLS and RLS are configured to emit light within the infrared (IR) and/or visible (VIS) and/or the ultraviolet (UV) spectral range.

29. The method of any one or more of claims 17 to 28 further comprising ongoing measuring of fluorescence and/or scattered light emanating from a fluid sample, sampled from the fluid facility.

30. The method of claim 29 further comprising determining of an updated value of one or more of: concentration of one or more chemical and/or biological substances; fluid hardness; fluid turbidity level.

31. A system for monitoring one or more attributes of a fluid from a fluid facility, the system comprising at least: a cuvette for containing therein a fluid sample, sampled from the fluid facility; at least one main light source (MLS); at least one reference light source (RLS); a spectral detector; an inspection optical detector; one or more optical elements configured and arranged such as to direct light from the MLS towards the cuvette and towards the inspection optical detector and from the RLS at least towards the inspection optical; and a processing and control unit configured at least to: control operation of the MLS and of the RLS; receive updated MLS data, indicative of optical characteristics associated with light emanating from the MLS; receive updated RLS data, indicative of optical characteristics associated with light emanating from the RLS; analyze the received updated MLS and RLS data to identify changes in optical characteristics of MLS data; determine whether detected changes in optical characteristics of the MLS data require performing at least one mitigation action; and perform at least one determined mitigation action when such is determined to be required.