METHOD FOR POWER-SAVING CONTINUOUS MEASUREMENT OF THE QUALITY OF A LIQUID AND MEASURING DEVICE FOR PERFORMING THE METHOD

Description

[0001] The invention relates to a method for energy-saving continuous measurement of the quality of a liquid, in particular water, with a sensor for detecting a measured quantity.

[0002] Furthermore, the invention relates to a measuring device for the energy-saving continuous measurement of the quality of a liquid, in particular water, with a sensor.

[0003] As is well known, the quality of liquids, such as water, is measured using sensors, which are powered by electrical energy. If no external power supply is permanently available, the energy for the sensors is provided by electrical energy storage devices, such as batteries, especially rechargeable batteries. These electrical energy storage devices are replaced or recharged during maintenance, which, however, involves a corresponding maintenance effort. Therefore, it is desirable to maintain a charged state of the energy storage devices for as long as possible, i.e., to operate the sensors as energy-efficiently as possible. This is often achieved by extending the measurement interval, i.e., by longer time intervals between successive measurements with the sensor. Between measurements, the sensor is deactivated, and the sensor's control unit is put into a sleep or rest state.After a defined period of time, the controller leaves standby mode and activates the sensor briefly to perform the measurement.

[0004] While such power-saving operation is quite practical for some sensors, other sensors for measuring the quality of liquids, especially water, require a virtually continuous power supply, or at least a comparatively much longer power supply, e.g., several hours, to deliver accurate measurements. If these other sensors were powered for several hours to obtain a single measurement and then deactivated to save energy, they would yield only a few measurements per day. Such a low measurement rate is often insufficient for measuring the quality of liquids, especially water.

[0005] As described in AT 520515 A1, water quality sensors are sometimes connected to pumps that ensure water transport to the sensor. In such systems, taking measurements requires activating both the sensor and the associated pump, further increasing overall energy consumption. Apart from a short lead time to ensure water exchange before sensor activation, the pump can also be switched off during the sensor's power-off phase, further reducing energy consumption.

[0006] EP 3 194 908 B1 concerns monitoring systems, for example, for pipeline or pipe networks. The monitoring system can include a wireless telemetry unit connected to at least one threshold indicator for detecting a liquid level and at least one sensor to determine the condition of the liquid in a pipe of the network. The telemetry unit can supply power to the sensor when the threshold indicator shows a liquid level above a threshold. Likewise, the telemetry unit can interrupt the power supply to the sensor when the threshold indicator shows a liquid level below the threshold. This reduces the sensor's power consumption. The document already mentions that the sensor requires a certain amount of time to warm up once it is powered on. Details regarding the warm-up phase or solutions for circumventing this warm-up time are not provided.

[0007] US 2020 / 0340968 A1 concerns a device for monitoring parameters of liquids, such as water quality, in an energy-saving manner. The device includes, for example, a chlorine sensor and a controller that regulates the device's operation between at least a switched-off mode, an active mode in which the device performs measurements, and a standby mode in which no measurements are taken and the controller and the chlorine sensor are supplied with only minimal power, so that the chlorine sensor does not enter a passive mode and therefore does not require recalibration. The minimal energy required for this can be supplied by batteries. US 2020 / 0340968 A1 thus describes a power-saving operation of a chlorine sensor, but not how to switch the sensor off between successive measurements or how to prevent the associated measurement inaccuracies.

[0008] JP S59 162444 A discloses a device and a method for measuring the aging of oil, e.g., in motor vehicles. For this purpose, the oil temperature is first measured, and if it is within a defined temperature range, a voltage pulse is applied to an electrode located in the oil. The change over time of the current flowing through the oil as a result of the voltage pulse is measured, and the oil aging is inferred from this. US 4 464 230 A discloses a method for detecting the oxygen content in a fluid stream, e.g., water. For this purpose, an electrode is inserted into the water, activated for an initial period of time, and then deactivated for a time interval longer than the activation period.

[0009] US Patent 2009 / 068754 A1 concerns a biosensor system that determines the analyte concentration of, for example, alcohol, glucose, uric acid, lactate, cholesterol, bilirubin, and the like in a biological sample from an initial signal with a decaying profile. A sensor strip, which picks up the sample to be measured, is excited by one or more pulses of electricity.

[0010] The object of the invention is to provide a method and a measuring device of the type mentioned above, which enable energy-saving continuous measurement of the quality of a liquid, in particular water, using a sensor. In particular, the sensor should operate with lower power consumption compared to conventional operation, while still obtaining measurement results with essentially the same accuracy as in the case of conventional operation with higher power consumption.

[0011] For this purpose, the invention provides a method as defined in claim 1 and a measuring device as defined in claim 12. Advantageous embodiments and further developments are specified in the dependent claims.

[0012] The object is achieved according to the invention by a method for energy-saving continuous measurement of the quality of a liquid, in particular water, with a sensor for detecting a measured quantity, wherein: S1) the sensor is provided as part of a measuring device for measuring liquid quality and the measuring device is arranged relative to the liquid; S2) the sensor is alternately activated for the duration of a switch-on phase and deactivated for the duration of a switch-off phase; S3) a switch-on phase is defined as a switch-on phase in a steady state of the sensor and a measured value is acquired with the sensor as a reference measured value during the defined switch-on phase, wherein the steady state is reached when a value of the measured quantity differs by at most a predetermined difference from a value of the measured quantity during a previous switch-on phase; S4) a reference measurement is carried out to acquire a measured value representing the liquid quality, as a reference measured value;S5) during further switch-on phases following the defined switch-on phase, measured values ​​are continuously recorded as operating measured values ​​with the sensor; S6) a calculation rule is defined which assigns the comparison measured value to the reference measured value; and S7) a final measured value for measuring quality is determined from each operating measured value using the calculation rule; wherein, for the execution of the reference measurement S4b), the defined switch-on phase or a switch-on phase between the defined switch-on phase and the further switch-on phases for recording the operating measured values ​​is extended compared to the preceding switch-on phases, and the reference measured value is recorded with the sensor during the extended switch-on phase.

[0013] The sensor is thus provided in step S1 as part of a measuring device for measuring liquid quality, and the measuring device is positioned relative to the liquid. The sensor is placed within the liquid. The part of the measuring device not containing the sensor can be at least partially submerged in the liquid or positioned at a distance from it. For example, the part of the measuring device not containing the sensor is connected to the sensor via an electrically conductive cable. Alternatively, the sensor can be integrated into the measuring device.

[0014] In step S2, the sensor is alternately activated for the duration of an on-phase and deactivated for the duration of an off-phase. In the activated state, the sensor is supplied with electrical current, and in the deactivated state, it is not. This ensures energy-efficient operation of the sensor and an energy-efficient process. The duration of the on-phase and the duration of the off-phase can be set by the operator of the measuring device.

[0015] In step S3, the sensor acquires a reference measurement during a defined power-on phase. During this phase, the reference measurement differs from a previously acquired value by a predetermined difference. It should be noted that the measured value, even if the measured quantity remains constant, changes due to the sensor's alternating activation and deactivation during the power-on phases. Therefore, when the description refers to acquiring or comparing multiple measurements, it is understood that the measurements are taken at similar, and in particular, equal time intervals from the start of each power-on phase to ensure accurate and comparable results.For a correct comparison, the reference measurement and the measured value of a previous activation phase are preferably recorded or considered at equal time intervals from the start of the respective activation phase. The operator of the measuring device can define the activation phase. The reference measurement is thus recorded at the end of, or after, a settling-in period of the alternately activated and deactivated sensor, whereby the measured values ​​are essentially stable at equal intervals from the start of the activation phases, i.e., they do not differ from each other by more than the specified difference. This settling-in period occurs when the sensor is alternately activated and deactivated after an extended deactivation period compared to the duration of the deactivation phase (e.g., required for maintenance purposes) or after the sensor's initial activation.During the settling-in phase, the measured values ​​will initially differ across several successive switch-on phases, observed at equal intervals from the start of each phase, but will gradually converge towards the reference measurement. Thus, in step S3, a reference measurement representative of the duration of a switch-on phase of the steady-state sensor is acquired.

[0016] In step S4, a reference measurement is performed to acquire a measured value representing the liquid quality. The reference measurement acquires the measured value with an accuracy that could be achieved, for example, or approximately achieved, with the sensor if it were permanently activated.

[0017] In step S5, the sensor continuously records measured values ​​as operating parameters during subsequent power-on phases following the defined power-on phase. This recording of operating parameters corresponds to the continuous measurement of the liquid's quality, particularly water, and is interrupted at the latest by maintenance activity performed by the operator of the measuring device, e.g., for battery replacement. For accurate measurement, the operating parameters are preferably recorded at regular intervals from the start of the power-on phases.

[0018] In step S6, a calculation rule is defined that assigns the comparison measurement value to the reference measurement value. This calculation rule can, for example, be determined in the control system of the measuring device and stored in the device's memory.

[0019] In step S7, a final measurement value for measuring the liquid quality is determined from each operational measurement value using the calculation rule. This final measurement value thus represents the quality of the liquid, in particular water.

[0020] In step S4b, the defined switch-on phase, or a switch-on phase between the defined switch-on phase and subsequent switch-on phases, is extended compared to the preceding switch-on phases for acquiring the operating measurements. During this extended switch-on phase, the reference measurement is acquired by the sensor. The reference measurement is thus performed with higher accuracy compared to measurements taken during a single switch-on phase. The reference measurement is performed during an extended switch-on phase using the sensor itself. If the defined switch-on phase is extended for this purpose, the reference measurement is performed within the defined switch-on phase after the acquisition of the comparative measurement.

[0021] The method therefore involves not supplying the sensor with a continuous power supply, as is usually the case, but rather activating and deactivating it alternately in order to save energy and minimize the need to replace or recharge the energy storage device. After a sensor settling-in period, a comparative measurement with lower accuracy is acquired during a relatively short activation phase and assigned to a reference measurement with higher accuracy. During continuous measurement operation, further comparatively short activation phases capture operating measurements with lower accuracy. Finally, the inaccuracies of the operating measurements are corrected using the relationship between the comparative and reference measurements, resulting in final measurements with higher accuracy.

[0022] If the sensor is activated and deactivated periodically, at least intermittently, the accuracy of the reference measurement and / or the operational measurements can be improved. This is because the sensor readings can depend not only on the value of the measured quantity itself, but also on the duration of the preceding on and off phases. Constantly varying durations of the on and off phases can therefore lead to varying measurements even with a constant value of the measured quantity. It is particularly preferred that the sensor be activated and deactivated periodically, at least intermittently, during the ongoing measurement operation, after the defined on phase.

[0023] Regarding the defined switch-on phase, it may be provided that S3a) a switch-on phase is defined as a switch-on phase at least when a specified number of preceding switch-on phases are followed by a switch-off phase that is extended compared to the duration of the switch-off phase or by the first activation of the sensor.

[0024] The number of preceding switch-on phases can be adjusted. For example, an operator of the measuring device can determine this number based on experience. The number of preceding switch-on phases, and therefore also preceding switch-off phases, can be set so that the sensor is reliably in a steady state afterward. The defined number of preceding switch-on phases is counted from the moment the sensor is first switched on or following a prolonged interruption of the sensor's operation—that is, an interruption phase that is longer than the duration of previous interruptions or the average duration of previous interruptions. For example, an average interruption phase might be 20 minutes, while an interruption of operation might be 1 hour.

[0025] Regarding the defined switch-on phase, it may further be provided that S3b) a switch-on phase is defined at least by the following: Acquiring measured values ​​with the sensor in several successive switch-on phases; comparing the last recorded measured value with the previously recorded measured value; and in the event of a deviation between the two compared measured values ​​that falls below a predefined threshold, defining the switch-on phase for the last measured value as the defined switch-on phase.

[0026] This allows the switch-on phase to be defined as the switch-on phase during which the measured value differs from the previous measured value by less than the defined threshold. The sensor is thus in a steady state. For a correct comparison of the measured values, the measured values ​​are preferably recorded at equal time intervals from the beginning of the respective switch-on phase.

[0027] Furthermore, it is advantageous if the reference value and / or the operating value are acquired by measuring the reference value and / or the operating value at a defined target time within the start-up phase, particularly at the end of the start-up phase. This allows for particularly reliable measurement results, since, as previously mentioned, even with a constant measured quantity, the value detectable by the sensor changes due to the alternating activation and deactivation of the sensor during the start-up phases. The target time can, for example, be defined by the operator of the measuring device and may be adjustable. The target time can be, but does not have to be, at the end of the start-up phase.

[0028] Furthermore, it may be provided that the comparative measurement value and / or the operational measurement value is recorded by the following: Measuring with the sensor at several points in time within the switch-on phase associated with the reference measurement and / or operating measurement to obtain multiple samples; calculating a measurement profile approximating the samples within the switch-on phase; measuring at which actual time the reference measurement and / or operating measurement intended for measurement at a defined target time was actually measured; and in the event of a deviation of the actual time from the target time, calculating the reference measurement and / or operating measurement at the target time using the approximated measurement profile.

[0029] In this way, errors in the acquisition of the comparative measurement value and / or the operational measurement value can be corrected. These errors can arise because the intended measurement time, i.e., the target time, cannot be met. For example, the target time cannot be met due to system-related inaccuracies, such as a temporary overload of a processor in the measuring device. Based on knowledge of the measurement curve during the start-up phase, the measurement value at the intended target time can be calculated from the measurement value acquired at the actual time, preferably by the measuring device itself, in particular by interpolation or extrapolation. The target time can be earlier or later in time than the actual time.

[0030] A particularly simple embodiment may provide that The calculation procedure is defined as calculating a constant factor, which is formed from the quotient between the comparison measurement and the reference measurement, and the final measurement value is determined from each operating measurement value by dividing the operating measurement value by the calculated constant factor.

[0031] Therefore, it applies V / R = B / F = Q , F = B / Q where V is the comparison measurement, R is the reference measurement, B is an operating measurement, F is a final measurement, and Q is the constant factor.

[0032] The final measured values ​​calculated using these equations will closely approximate the actual value of the measured quantity, as long as the operating measurements deviate only slightly from the reference measurement. With increasing deviation, for example due to a change in liquid quality, this simple calculation method becomes less accurate because of the non-linear behavior of the measured quantity during the start-up phase.

[0033] To obtain the most accurate final measurements possible, it is advantageous to repeat steps S2) to S7) if several compared operating measurements or several compared final measurements differ from each other by more than a predefined threshold value.

[0034] Such a deviation between several compared operational or final measured values ​​indicates a change in the liquid's quality. Therefore, a change in the comparative and reference measured values ​​is to be expected, which is why steps S2) to S7) of the procedure are preferably repeated. The predefined threshold can, for example, be set by the operator of the measuring device. Preferably, the most recently measured operational or calculated final measured values ​​are compared with older operational or final measured values.

[0035] Furthermore, it is preferred that at least steps S2), S3), and S5) to S7) of procedure S9) be repeated if the duration of the switch-on phase and / or the duration of the switch-off phase has been changed by more than a predefined threshold. The change to the duration of the switch-on phase and / or the duration of the switch-off phase can be made by an operator of the measuring device, for example, to obtain final measured values ​​at shorter intervals or to further increase the energy savings achieved by the sensor. Since the measured values ​​that can be acquired by the sensor also depend on the duration of the switch-on phase and / or the duration of the switch-off phase, a change in the reference measurement is also to be expected, which is why at least steps S2), S3), and S5) to S7) of the procedure are preferably repeated.If the reference measurement process is independent of the changed switch-on / switch-off phases and therefore no new reference measurement value is to be expected, step S4) of the renewed reference measurement can also be omitted.

[0036] To obtain correct final measurements, it is advisable to perform steps S2) to S5) with the same liquid.

[0037] To obtain accurate final measurements with measuring devices in which a liquid pump supplies the sensor with liquid, it is advantageous if (S10) the liquid pump of the measuring device, which directs the liquid over the sensor, is activated upstream of the sensor, for example, one to two minutes before step (S2), particularly for a period sufficient to supply the liquid to the sensor. This ensures that the liquid at the sensor is replaced beforehand and, immediately at the time of activation, already corresponds representatively to the liquid present at the sampling point, for example, in a supply pipe.

[0038] It is particularly preferred that a sensor for measuring the concentration of a disinfectant, especially a chlorine concentration, or for measuring a pH value is used. These sensors typically require long activation times, preferably continuous operation, to deliver accurate measurement results. Furthermore, these sensors are particularly sensitive, at least with regard to varying liquid quality, varying durations of the on and off phases, the number of previous on and off phases, and the dwell time in the liquid. With the method according to the invention, final measured values ​​can be obtained with such sensors in a power-saving manner with an accuracy that would not be achievable by shorter on phases alone.

[0039] The problem stated at the outset is further solved according to the invention by a measuring device for the energy-efficient continuous measurement of the quality of a liquid, in particular water, comprising at least one sensor, an electrical energy storage device, and a control unit, which is characterized in that the control unit is configured to carry out a method according to the preceding description. The measuring device therefore has at least one sensor with which values ​​of the measured quantity representing the liquid quality, e.g., a concentration of a disinfectant, a chlorine concentration, or a pH value, can be detected. In order to be able to operate the measuring device independently of a power supply, it includes the electrical energy storage device. The control unit of the measuring device is configured to control the execution of the method described above.For this purpose, the measuring device preferably includes a microprocessor and a data storage device. Regarding the features of the measuring device, reference is also made to the preceding description of the method, insofar as this is helpful for understanding the measuring device and insofar as features of the measuring device can be derived from this description of the method. Likewise, reference is also made to the description of the measuring device with regard to the features of the method.

[0040] The sensor is particularly preferably designed to measure the concentration of a disinfectant, especially a chlorine concentration, or to measure a pH value.

[0041] The invention will be further explained below with reference to preferred, non-limiting embodiments and the drawing. The drawing shows: Fig. 1 a schematic representation of part of the temporal sequence of the process according to the invention; Fig. 2 a schematic representation of the temporal sequence of a switch-on phase on a larger scale; Fig. 3 a flowchart for the method according to the invention; Fig. 4 a more detailed flowchart for the method according to the invention; and Fig. 5 a simplified block diagram of the measuring device according to the invention.

[0042] Fig. 1 The diagram, not to scale, schematically depicts part of the temporal sequence of the method for the energy-saving continuous measurement FM of the quality of a liquid, in particular water. Before a time t0, a sensor 1, which is part of a measuring device 2 and serves to detect a measured quantity G representing the liquid quality, is provided, and the measuring device 2 is positioned relative to the liquid (in Fig. 1 (not shown). In the example shown, sensor 1 is activated for the first time at time t0 or after a comparatively long period without power. Sensor 1 can be sensor 1a for measuring the concentration of a disinfectant, in particular for measuring a chlorine concentration, or for measuring the pH value of the liquid. Following time t0, sensor 1, 1a is alternately activated for the duration of an on-phase TE and deactivated for the duration of an off-phase TA. Fig. 1 Several alternating switch-on phases TE and switch-off phases TA are shown. During some of the switch-on phases TE and switch-off phases TA following time t0, the sensor 1, 1a can settle. The settling phase EV results from the fact that the sensor 1, 1a, after its activation (in Fig. 1 At time t0), the sensor must be operated for a longer period compared to the duration of the switch-on phase TE, e.g., for several hours, to output correct measurement results. According to the procedure, however, sensor 1, 1a is only ever activated for the short duration of the switch-on phase TE. During this time, the value W of the measured quantity G, detectable by sensor 1, 1a, changes and approaches the correct measured value, which can only be measured after a correspondingly long time, both within the switch-on phases TE and with each subsequent switch-on phase TE. See the measured value L during a switch-on phase TE and in successive switch-on phases TE in [reference to diagram]. Fig. 1 In Fig. 1 The change in a measured value M from one switch-on phase TE to the next is detectable at the end of each switch-on phase TE during the settling phase EV. The settling phase EV extends over several, e.g., 5 to 10, switch-on phases TE and switch-off phases TA. After the settling phase EV, the same measured value M can be obtained with sensor 1, 1a in each switch-on phase TE, provided the liquid quality remains constant. The end of the settling phase EV constitutes a defined switch-on phase TED. During the defined switch-on phase TED, a measured value M is recorded with sensor 1, 1a as a reference value V, whereby the reference value V differs from a value W of the measured quantity G detectable during a previous switch-on phase TE by at most a predefined difference D.Regarding the value W of the measured quantity G that can be recorded during a previous switch-on phase TE, it is irrelevant whether the value W is actually recorded as a measured value M. What is essential in this context is only that the comparative measured value V differs from a value W of the measured quantity G of a preceding switch-on phase TE, e.g., the immediately preceding one, by at most the aforementioned difference D. This can also be achieved by defining a number of preceding switch-on phases TE and assuming that after this number of preceding switch-on phases TE, the comparative measured value V differs from a value W of the measured quantity G that can be recorded during a previous switch-on phase TE by at most the difference D.

[0043] Figure 1 further shows that a reference measurement RM is performed to determine a measured value M representing the liquid quality, which is called the reference measurement R. The reference measurement RM can be carried out in various ways, which is shown in Fig. 1 This is illustrated by the splitting of the time sequence at the point of the vertical dashed line into three alternative time sequences T1, T2, T3.

[0044] The time sequence T1 in Fig. 1 Figure 1 shows an implementation of the procedure in which the defined switch-on phase TED is extended compared to the preceding switch-on phases TE, thus constituting an extended switch-on phase TEV, during which the reference measurement R is acquired by sensor 1, 1a. The comparative measurement V is acquired during this extended switch-on phase TEV at the same time it would have been acquired if the defined switch-on phase TED had not been extended.

[0045] The time sequence T2 in Fig. 1 Figure 1 shows an implementation of the procedure in which a switch-on phase TEV is extended between the defined switch-on phase TED and the subsequent switch-on phases TEW, which serve to acquire the operating measured values ​​B. During the extended switch-on phase TEV, the reference measured value R is acquired with sensor 1, 1a.

[0046] The timeline T3 in Fig. 1 Figure 1 shows an embodiment not included in the method, according to which a liquid sample is taken from the liquid and the reference measurement value R of the taken liquid sample is recorded in a device external to the measuring device 2. The taking of the liquid sample, the recording of the reference measurement value R, and the external device are shown in Figure 2. Fig. 1 not shown.

[0047] Regardless of how the reference measurement value R is acquired, during subsequent switch-on phases TEW following the defined switch-on phase TED, i.e., during the continuous measurement FM, sensor 1, 1a continuously acquires measured values ​​M as operating measurements B. From each operating measurement B, a final measured value F for measuring quality is determined using a defined calculation formula, whereby the calculation formula assigns the comparison measurement value V to the reference measurement value R.

[0048] Fig. 1 It also shows a time sequence of the activation state Z of sensor 1, 1a, which can be in an activated state ZA and a deactivated state ZD. The time sequence T4 is shown in Fig. 1 the time sequence T1 from Fig. 1 assigned the time sequence T5 in Fig. 1 is the time T2 from Fig. 1 assigned and the time sequence T6 in Fig. 1 is the time T3 from Fig. 1 assigned.

[0049] In Fig. 1 It is further indicated that sensor 1, 1a is activated and deactivated at least periodically. Due to system limitations, such as a temporary overload of the measuring device, the periodic sequence may be subject to slight variations, in which case the sequence is still considered periodic. Such acceptable deviations from exact periodicity can range from several seconds to, for example, 10 seconds, if the duration of the activation phase (TE) is between 2 and 4 minutes and the duration of the deactivation phase is between 10 and 20 minutes.

[0050] The defined switch-on phase TED can, for example, be defined as the switch-on phase TE that, viewed from time t0, follows a specified number of preceding switch-on phases TE. In the example according to Fig. 1 This fixed number is at least three. The defined switch-on phase TED can, for example, also be defined as the switch-on phase TE for which a measured value M recorded with sensor 1, 1a differs from a measured value M recorded in a previous switch-on phase TE by less than a predefined threshold value D.

[0051] In the Fig. 1 In the example shown, the measured value M, in particular the comparative measured value V and / or the operating measured value B, is recorded at the end of the switch-on phases TEE. Generally, however, the target time TS at which the measured values ​​M are measured within the switch-on phase TE can be predetermined and may also deviate from the end of the switch-on phases TEE. For example, the time sequence T1 in Fig. 1 a recording of the comparative measurement value V and a recording of the reference measurement value R within the same switch-on phase TE at different times.

[0052] The switch-on phase TE can, for example, be between 2 and 4 minutes, preferably between 2.5 and 3.5 minutes, and in particular 3 minutes. The switch-off phase TA can, for example, be between 10 and 20 minutes, preferably between 13 and 17 minutes, and in particular 15 minutes. The extended switch-on phase TEV can, for example, extend over a period of between 1 and 3 hours, preferably between 1.5 and 2.5 hours, and in particular 2 hours.

[0053] Fig. 2 This example shows the acquisition of the comparative measurement value V and / or an operating measurement value B, or more generally, a measured value M, using an approximate measurement profile L. For this purpose, during the switch-on phase TE, in which the comparative measurement value V and / or the operating measurement value B are to be acquired, several measured values ​​are acquired as samples A at several time points TA using sensor 1, 1a. Subsequently, a measurement profile L approximating the samples A is calculated within the switch-on phase TE. Since the acquisition of the comparative measurement value V and / or the operating measurement value B is to take place at a target time TS, the actual time TI at which the comparative measurement value V and / or the operating measurement value B was actually measured is now measured. Should an undesired occurrence, e.g.,Due to overload of the measuring device, if the actual time TI deviates from the target time TS, the comparative measured value V and / or operating measured value B is calculated using the approximate measured value profile L to the target time TS. In the following... Fig. 2 In the example shown, the measurement was unintentionally delayed, meaning the target time TS is before the actual time TI, which would erroneously record the measured value M at the wrong time. To correct this error, the measured value M at the target time TS can be calculated from the measured value history L.

[0054] Fig. 3 Figure 1 shows a simplified flowchart according to the procedure. Steps S1 to S7 do not necessarily have to be carried out in the specified order. Rather, the person skilled in the art can determine a suitable sequence for steps S1 to S7.

[0055] In step S1, the sensor 1, 1a is provided as part of a measuring device 2 for measuring the liquid quality and the measuring device 2 is positioned relative to the liquid.

[0056] In step S2, sensor 1, 1a is alternately activated for the duration of a switch-on phase TE and deactivated for the duration of a switch-off phase TA. In particular, sensor 1, 1a can be activated and deactivated periodically, at least temporarily.

[0057] In step S3, a measured value M is recorded as a comparative measurement V using sensor 1, 1a during a defined switch-on phase TED, for which defined switch-on phase TED the comparative measurement V differs by at most a predetermined difference D from a value W of the measured quantity G that can be recorded during a previous switch-on phase TE.

[0058] In step S4, a reference measurement RM is performed to acquire a measured value M representing the liquid quality, which is used as the reference measurement R. Depending on the method used to acquire the reference measurement M, step S4 can also be performed earlier. The possibility of earlier acquisition is described in Fig. 3 indicated by the dashed line representing steps S4.

[0059] In step S5, during further switch-on phases TEW, which follow the defined switch-on phase TED, measured values ​​M are continuously recorded as operating measured values ​​B using sensor 1, 1a.

[0060] Steps S2 to S5 are preferably performed using the same liquid.

[0061] In step S6, a calculation rule is defined that assigns the comparative measurement value V to the reference measurement value R. Step S6 can be executed as soon as the comparative measurement value V and the reference measurement value R are known, in particular before step S5.

[0062] In step S7, a final measured value F for measuring quality is determined from each operational measurement value B using the calculation rule.

[0063] It is evident that some steps of the process are executed simultaneously. At least steps S3 and S5 through S7 are performed while step S2 is being executed.

[0064] Fig. 4 A more detailed flowchart is shown according to the procedure. In this example as well, the specified steps S1 to S10 do not necessarily have to be carried out in the given order. Steps S1 to S7 according to Fig. 4 correspond to steps S1 to S7 according to Fig. 3 and are therefore associated with Fig. 4 not described again.

[0065] Step S3 can include either step S3a or step S3b. In step S3a, a switch-on phase TE is defined as a switch-on phase TED if a specified number of preceding switch-on phases TE are followed by a switch-off phase TA that is extended compared to the duration of the switch-off phase TA, or by the initial activation of sensor 1, 1a. In step S3b, a switch-on phase TE is defined as a switch-on phase TED by the following: Measurement values ​​M are acquired with sensor 1, 1a in several successive switch-on phases TE. The last acquired measurement value M is compared with the previously acquired measurement value M. If the difference between the two compared measurement values ​​M falls below a predefined threshold, the switch-on phase TE for the last measurement value M is defined as the switch-on phase TED.Furthermore, the defined TED activation phase can also be set in other ways.

[0066] Step S4 may not include a step S4a according to the procedure or a step S4b according to the procedure. In step S4a, a liquid sample is taken from the liquid, and the reference measurement value R of the taken liquid sample is recorded in a device external to measuring device 2. In step S4b, the defined switch-on phase TED or a switch-on phase TEV is extended between the defined switch-on phase TED and the further switch-on phases TEW, which serve to record the operating measurements B. During the extended switch-on phase TEV, the reference measurement value R is recorded with sensor 1, 1a.

[0067] In steps S3 and / or S5, it may also be provided that the comparative measurement value V and / or the operating measurement value B are recorded by measuring the comparative measurement value V and / or the operating measurement value B at a defined target time TS within the switch-on phase TE, in particular at the end of the switch-on phase TEE.

[0068] Furthermore, steps S3 and / or S5 may provide for the comparison measurement value V and / or the operating measurement value B to be recorded by the following: Measuring with sensor 1, 1a at several time points TA within the switch-on phase TE assigned to the reference measurement V and / or operating measurement B, in order to obtain several sampled values ​​A; calculating a measured value profile L approximating the sampled values ​​A within the switch-on phase TE; measuring at which actual time TI the reference measurement V and / or operating measurement B intended for measurement at a defined target time TS was actually measured; and in the event of a deviation of the actual time TI from the target time TS, calculating the reference measurement V and / or operating measurement B at the target time TS using the approximated measured value profile L.

[0069] In step S6, it may also be stipulated that the calculation procedure is defined as calculating a constant factor Q, which is formed from the quotient between the comparison measurement V and the reference measurement R.

[0070] In step S7, it may also be provided that the final measured value F is determined from each operational measured value B by dividing the operational measured value B by the calculated constant factor Q.

[0071] In step S8, steps S2 to S7 are repeated if several compared operating measurements B or several compared final measurements F differ from each other by more than a predefined threshold.

[0072] In step S9, at least steps S2, S3 and S5 to S7 are repeated if the duration of the switch-on phase TE and / or the duration of the switch-off phase TA has changed by more than a predefined threshold.

[0073] In step S10, a liquid pump 3 of the measuring device 2, which directs the liquid via the sensor 1, 1a, is activated before the sensor (1, 1a), for example one minute to two minutes before step S2), in particular for a period of time which is sufficient to supply the liquid to the sensor (1, 1a).

[0074] Fig. 5Figure 1 shows a simplified block diagram of a measuring device 2 for the energy-efficient continuous measurement FM of the quality of a liquid, in particular water. The measuring device 2 comprises at least one sensor 1, 1a, an electrical energy storage device 4, and a controller 5. The controller 5 is configured to execute and control the process. A liquid pump 3 may also be included. The controller 5 is connected to the sensor 1, 1a, the electrical energy storage device 4, and the liquid pump 3. The electrical energy storage device 4 is also connected to the sensor 1, 1a, and the liquid pump 3. The measuring device 2 may also include a data storage device 8, an input device 6 for inputting parameters, e.g., a reference value R, and an output device 7, at least for the final measured values ​​F.In addition, the output device 7 can issue a notification if several compared operating measurements B or several compared final measurements F differ from each other by more than a predefined threshold.

Claims

1. Method for energy-saving continuous measuring (FM) of the quality of a fluid, in particular water, with a sensor (1, 1a) for capturing a measured quantity (G), wherein: S1) the sensor (1, 1a) is provided as part of a measuring device (2) for measuring the liquid quality and the measuring device (2) is arranged relative to the fluid; S2) the sensor (1, 1a) is alternately activated for the duration of a switch-on phase (TE) and deactivated for the duration of a switch-off phase (TA); S3) a switch-on phase (TE) in a steady state of the sensor (1, 1a) is defined as a defined switch-on phase (TED) and a measured value (M) is determined with the sensor (1, 1a) during the defined switch-on phase (TED) as a comparative measured value(V) is captured, the steady state being reached when a value (W) of the measured quantity (G) differs by at most a predetermined difference (D) from a value (W) of the measured quantity (G) during a previous switch-on phase (TE); S4) a reference measurement (RM) is performed to capture a measured value (M) representing the liquid quality as a reference measured value (R); S5) with the sensor (1, 1a) during further switch-on phases (TEW), which follow the defined switch-on phase (TED), measured values (M) are continuously captured as operating measured values (B); S6) a calculation method is defined which assigns the comparative measured value (V) to the reference measured value (R); and S7) a final measured value (F) for measuring the quality is determined from each operating measured value (B) by means of the calculation method; characterized in that for carrying out the reference measurement (RM) S4b) the defined switch-on phase (TED) or a switch-on phase (TEV) between the defined switch-on phase (TED) and the further switch-on phases (TEW) is extended compared to the previous switch-on phases (TE) in order to capture the operating measured values (B), and during the extended switch-on phase (TEV) the reference measured value (R) is captured with the sensor (1, 1a).

2. Method according to claim 1, characterized in that the sensor (1, 1a) is activated and deactivated at least periodically.

3. Method according to claim 1 or 2, characterized in that S3a) a switch-on phase (TE) is defined as a defined switch-on phase (TED) at least if a defined number of preceding switch-on phases (TE) follow a switch-off phase (TA) that is longer than the duration of the switch-off phase (TA) or if the sensor (1, 1a) is activated for the first time.

4. Method according to claim 1 or 2, characterized in that S3b) a switch-on phase (TE) is defined as a defined switch-on phase (TED) by at least the following: - Capturing measured values (M) with the sensor (1, 1a) in several successive switch-on phases (TE); - Compare the last measured value (M) captured with the previous measured value (M); and - in the event of a deviation of the two compared measured values (M) from each other that does not exceed a predefined threshold value, setting the switch-on phase (TE) for the last measured value (M) as the defined switch-on phase (TED).

5. Method according to one of claims 1 to 4, characterized in that the comparative measured value (V) and / or the operating measured value (B) are captured by measuring the comparative measured value (V) and / or the operating measured value (B) at a fixed target-time (TS) within the switch-on phase (TE), in particular at the end of the switch-on phase (TEE).

6. Method according to one of claims 1 to 5, characterized in that the comparative measured value (V) and / or the operating measured value (B) are captured by the following: - Measuring with the sensor (1, 1a) at several points in time (TA) within the switch-on phase (TE) assigned to the comparative measured value (V) and / or operating measured value (B) in order to obtain several scanning values (A); - Calculation of a measured value progression (L) approximated to the scanning values (A) within the switch-on phase (TE); - Measuring the actual-time (TI) at which the comparative measured value (V) and / or operating measured value (B) intended for measurement at a defined target-time (TS) was actually measured; and - in the event of a deviation of the actual-time (TI) from the target-time (TS), calculation of the comparative measured value (V) and / or operating measured value (B) to the target-time (TS) using the approximated measured value progression (L).

7. Method according to any one of claims 1 to 6, characterized in that - the calculation method is defined as calculating a constant factor (Q), which formed from the quotient between the comparative measured value (V) and the reference measured value (R), and - the final measured value (F) is determined from each operating measured value (B) by dividing the operating measured value (B) by the calculated constant factor (Q).

8. Method according to any one of claims 1 to 7, characterized in that S8) steps S2) to S7) are performed again if several operating measured values (B) compared with each other or several final measured values (F) compared with each other deviate from each other by more than a predefined threshold value.

9. Method according to any one of claims 1 to 8, characterized in that S9) at least steps S2), S3) and S5) to S7) are performed again if the duration of the switch-on phase (TE) and / or the duration of the switch-off phase (TA) has been changed by more than a predefined threshold value.

10. Method according to any one of claims 1 to 9, characterized in that S10) a fluid pump (3) of the measuring device (2), whereby fluid pump (3) directs the fluid over the sensor (1, 1a), is already activated before the sensor (1, 1a), already before the sensor (1, 1a) is activated, for example, one minute to two minutes before step S2) is activated, in particular for a period of time which is sufficient to supply the fluid to the sensor (1, 1a) before the sensor (1, 1a) is activated.

11. Method according to any one of claims 1 to 10, characterized in that the sensor (1, 1a) used is a sensor (1a) for measuring the concentration of a disinfectant, in particular for measuring a chlorine concentration, or for measuring a pH value.

12. Measuring device (2) for the energy-saving continuous measuring (FM) of a quality of a fluid, in particular of water, comprising at least one sensor (1, 1a), a storage (4) for electrical energy and a controlling unit (5), characterized in that the controlling unit (5) is designed to carry out a method according to claims 1 to 11.

13. Measuring device (2) according to claim 12, characterized in that the sensor (1, 1a) is designed for measuring the concentration of a disinfectant, in particular for measuring a chlorine concentration, or for measuring a pH value.