WO2017130085A1 - Probe for measuring turbidity, high turbidity and/or suspended solids at low consumption - Google Patents

Probe for measuring turbidity, high turbidity and/or suspended solids at low consumption Download PDF

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Publication number
WO2017130085A1
WO2017130085A1 PCT/IB2017/050299 IB2017050299W WO2017130085A1 WO 2017130085 A1 WO2017130085 A1 WO 2017130085A1 IB 2017050299 W IB2017050299 W IB 2017050299W WO 2017130085 A1 WO2017130085 A1 WO 2017130085A1
Authority
WO
WIPO (PCT)
Prior art keywords
capacitor
probe
suspended solids
turbidity
measuring
Prior art date
Application number
PCT/IB2017/050299
Other languages
French (fr)
Inventor
Aldo BIANCHINI
Original Assignee
B&C Electronics S.R.L.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by B&C Electronics S.R.L. filed Critical B&C Electronics S.R.L.
Publication of WO2017130085A1 publication Critical patent/WO2017130085A1/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
    • G01N21/3577—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing liquids, e.g. polluted water
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
    • G01N15/06—Investigating concentration of particle suspensions
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47—Scattering, i.e. diffuse reflection
    • G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
    • G01N21/53—Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
    • G01N15/075—
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
    • G01N2015/0042—Investigating dispersion of solids
    • G01N2015/0053—Investigating dispersion of solids in liquids, e.g. trouble

Definitions

  • the present invention refers to a probe for measuring turbidity, high turbidity and/or suspended solids at low consumption.
  • the probes for measuring turbidity operate on the principle of light reflected at 90° from the suspended particles.
  • the probes for measuring high turbidity and/or suspended solids operate on the principle of light retro- reflected by the suspended particles.
  • the probe comprises a light source, for example infrared, which is sent to the sample under examination, a detector of the light reflected by the suspended particles and a detector forming part of a diagnostic system able to highlight abnormal operating conditions such as the absence of liquid sample or fouling of the measurement windows.
  • a light source for example infrared
  • the turbidity probes currently on the market are designed to allow continuous analysis of the sample in which they are immersed. This requires a fairly high energy consumption due to the light source and all the measurement electronics. Said probes therefore have to be permanently connected to the electrical mains so that the energy required for performing the measurement is always available, thus limiting their use in applications where energy availability is limited .
  • the object of the present invention is to provide a probe for measuring turbidity, high turbidity and/or suspended solids at low consumption.
  • a further object is to provide a probe that can be supplied with a limited energy source, for example one or more batteries.
  • a further object is to provide a probe which is easy to produce.
  • a probe for measuring turbidity, high turbidity and/or suspended solids at low consumption comprising: a power supply source connected to a current limiter which supplies at least one capacitor connected to ground; said current limiter limits the current at its output to a maximum current equal to 1 mA; said at least one capacitor is connected to a controlled switch which in turn is connected to an electronic circuit for measuring turbidity and suspended solids; and comprises a microprocessor which periodically opens said switch for a first predetermined time to recharge said at least one capacitor, and which periodically closes said switch for a second predetermined time to perform said measurement of the turbidity and suspended solids; said electronic circuit for measuring the turbidity and/or suspended solids comprises a light emitter, a first receiver of the infrared light reflected by the suspended particles, and a second control receiver of the infrared light reflected .
  • a method for measuring turbidity, high turbidity and/or suspended solids comprising the steps of: providing a power supply to at least one capacitor by means of a current limiter, which limits the current at its output to a maximum current equal to 1 mA; charging said at least one capacitor for a first predetermined time period; supplying an electronic circuit for measuring turbidity and suspended solids by means of said capacitor for a second predetermined time period ; sending an infrared light, receiving the infrared light reflected by the suspended particles and receiving the control reflected infrared light.
  • the probe Due to a special and innovative management of the measuring cycle, and in particular due to the current limiter, the probe has very low energy consumption with respect to the solutions offered by the competitors, allowing use in applications where the quantity of energy available is limited (e.g. battery systems) or where connection to the electrical mains is not available.
  • the measurement is performed periodically, thus further reducing consumption, and at the same time a minimum current charges the capacitor which is used to supply the measurement circuit.
  • figure 1 shows a block diagram of a probe for measuring turbidity, high turbidity and suspended solids at low consumption, according to the present invention.
  • a probe for measuring turbidity, high turbidity and suspended solids at low consumption comprises an external power supply source 10, for example a battery, which supplies a voltage ranging for example from 7 to 30 Volts, to which a voltage regulator 1 1 is connected which supplies a stabilized voltage for example at 5.8 V, followed by a current limiter 12 which limits the cu rrent at its output to a maximum current wh ich in the embod iment example is equal to 1 mA.
  • the output of the current limiter 12 is connected to a term inal of a capacitor 1 3, or several capacitors, in th is particular case having a capacity of 1 880 p F (4 x 470 p F), the other terminal of the capacitor being connected to g round .
  • the capacitor 1 3 is then connected to a voltage regulator 14 which supplies a voltage for example of 5 V, in turn connected to a controlled switch 1 5.
  • the output of the controlled switch 1 5 is connected to and supplies a light emitter 20, for example infrared , which is located inside the probe, a first receiver 21 of the light emitted by the device and reflected by the suspended particles , a second control receiver 22 of the infrared lig ht reflected and if necessary a temperatu re sensor 23.
  • a light emitter 20 for example infrared
  • first receiver 21 of the light emitted by the device and reflected by the suspended particles
  • a second control receiver 22 of the infrared lig ht reflected if necessary a temperatu re sensor 23.
  • the capacitor 1 3 is also connected to a voltage regulator 25 wh ich supplies a voltage for example of 4.5 V to a microprocessor 26.
  • the microprocessor 26 is connected to an interface circuit 27 for analogy retransmission of the electrical signal proportional to the turbidity value measured .
  • the microprocessor 26 is fu rther connected to a digital interface circuit 28 wh ich , if necessary, allows the probe to communicate with the outside world via GSM , Bluetooth, RS485 protocols, etc.
  • the interface 28 can be used to programme and/or calibrate the probe itself.
  • the microprocessor controls and manages all the electronic circuit just described .
  • the electronic circuits are not further described as they are known to an expert in the sector.
  • the probe In the operating phase the probe is supplied by a battery and therefore the electronic circuits must have a low consumption.
  • the microprocessor 26 is programmed so as to periodically perform measurement of the turbidity and therefore remain in rest mode and with the switch 15 open so as not to supply the circuits 20-23 for a predetermined time, which in the example is 8 seconds.
  • a measurement acquisition device like a datalogger or a GSM card which will send the values to their destination can be applied to the interface 28.
  • the measurement cycle is then repeated .
  • the switch 1 5 remains closed for approximately 50 ms, during the measurement phase and remains open for 8 s, to recharge the capacitor 1 3.
  • the turbid ity measurement is then repeated periodically every 8 s.
  • the presence of the voltage regu lators 1 1 , 14 and 25 is preferable in order to ensure a constant power supply voltage that does not vary with variation in the voltage at the ends of the capacitor 1 3 or with variation in the voltage of the battery 1 0.
  • the mean energy absorption from the power supply source 1 0 is lower than 1 mA and equal to approximately 0.7-0.8 mA, although during the measurement period the current supplied by the capacitor can even be equal to 25- 30 mA, in particular d uring activation of the lig ht transmitter 20 (for approximately 5 ms only) .
  • the initial voltage of approximately 5.8 V at the ends of the capacitor 1 3 d uring the measurement period decreases but the charging time of the capacitor 1 3 and the measurement time have been calculated so that it never d rops below approximately 5.2 V. With this voltage, the voltage regulator 25 is able to supply a voltage of 4.5 V to the microprocessor 26.
  • the microprocessor 26 is connected upstream of the switch 1 5 and is therefore always supplied by the capacitor 1 3.
  • the presence of the current limiter 1 2 means that the current consumption is limited to a maximum value which in the embodiment example is 1 mA.
  • the electronic circuits present are therefore supplied by the capacitor 1 3 without further absorption of energy from the supply sou rce 1 0 with the exception of the supply of 1 mA maximum.
  • the electronic circuits may be produced in any way according to requirements and the state of the art.

Abstract

A probe for measuring turbidity, high turbidity and/or suspended solids at low consumption, comprising: a power source; connected to a current limiter that supplies at least one capacitor connected to ground; said current limiter limits the current at its output to a maximum current of 1 mA; said at least one capacitor is connected to a controlled switch, which is in turn connected to an electronic circuit for measuring turbidity and suspended solids; a microprocessor which periodically opens said switch for a first predetermined time to recharge said at least one capacitor, and which periodically closes said switch for a second predetermined time to perform said measurement of turbidity and suspended solids; said electronic circuit for measuring the turbidity and/or suspended solids comprises a light emitter, a first receiver of the infrared light reflected by the suspended particles, and a second control receiver of the infrared light reflected.

Description

"PROBE FOR MEASURING TURBIDITY, HIGH TURBIDITY AND/OR SUSPENDED SOLIDS AT LOW CONSUMPTION"
DESCRIPTION
The present invention refers to a probe for measuring turbidity, high turbidity and/or suspended solids at low consumption.
The probes for measuring turbidity operate on the principle of light reflected at 90° from the suspended particles.
The probes for measuring high turbidity and/or suspended solids operate on the principle of light retro- reflected by the suspended particles.
The probe comprises a light source, for example infrared, which is sent to the sample under examination, a detector of the light reflected by the suspended particles and a detector forming part of a diagnostic system able to highlight abnormal operating conditions such as the absence of liquid sample or fouling of the measurement windows.
The turbidity probes currently on the market are designed to allow continuous analysis of the sample in which they are immersed. This requires a fairly high energy consumption due to the light source and all the measurement electronics. Said probes therefore have to be permanently connected to the electrical mains so that the energy required for performing the measurement is always available, thus limiting their use in applications where energy availability is limited .
The object of the present invention is to provide a probe for measuring turbidity, high turbidity and/or suspended solids at low consumption.
A further object is to provide a probe that can be supplied with a limited energy source, for example one or more batteries.
A further object is to provide a probe which is easy to produce.
According to the present invention, said objects and others are achieved by a probe for measuring turbidity, high turbidity and/or suspended solids at low consumption comprising: a power supply source connected to a current limiter which supplies at least one capacitor connected to ground; said current limiter limits the current at its output to a maximum current equal to 1 mA; said at least one capacitor is connected to a controlled switch which in turn is connected to an electronic circuit for measuring turbidity and suspended solids; and comprises a microprocessor which periodically opens said switch for a first predetermined time to recharge said at least one capacitor, and which periodically closes said switch for a second predetermined time to perform said measurement of the turbidity and suspended solids; said electronic circuit for measuring the turbidity and/or suspended solids comprises a light emitter, a first receiver of the infrared light reflected by the suspended particles, and a second control receiver of the infrared light reflected .
Said objects are furthermore achieved by a method for measuring turbidity, high turbidity and/or suspended solids comprising the steps of: providing a power supply to at least one capacitor by means of a current limiter, which limits the current at its output to a maximum current equal to 1 mA; charging said at least one capacitor for a first predetermined time period; supplying an electronic circuit for measuring turbidity and suspended solids by means of said capacitor for a second predetermined time period ; sending an infrared light, receiving the infrared light reflected by the suspended particles and receiving the control reflected infrared light.
Further characteristics of the invention are described in the dependent claims.
This solution offers several advantages with respect to the solutions of the known art.
Due to a special and innovative management of the measuring cycle, and in particular due to the current limiter, the probe has very low energy consumption with respect to the solutions offered by the competitors, allowing use in applications where the quantity of energy available is limited (e.g. battery systems) or where connection to the electrical mains is not available.
The measurement is performed periodically, thus further reducing consumption, and at the same time a minimum current charges the capacitor which is used to supply the measurement circuit.
The characteristics and advantages of the present invention will become evident from the following detailed description of a practical embodiment thereof, illustrated by way of non-limiting example in the accompanying drawings, in which:
figure 1 shows a block diagram of a probe for measuring turbidity, high turbidity and suspended solids at low consumption, according to the present invention.
Referring to the attached figures, a probe for measuring turbidity, high turbidity and suspended solids at low consumption, according to the present invention, comprises an external power supply source 10, for example a battery, which supplies a voltage ranging for example from 7 to 30 Volts, to which a voltage regulator 1 1 is connected which supplies a stabilized voltage for example at 5.8 V, followed by a current limiter 12 which limits the cu rrent at its output to a maximum current wh ich in the embod iment example is equal to 1 mA.
The output of the current limiter 12 is connected to a term inal of a capacitor 1 3, or several capacitors, in th is particular case having a capacity of 1 880 p F (4 x 470 p F), the other terminal of the capacitor being connected to g round .
The capacitor 1 3 is then connected to a voltage regulator 14 which supplies a voltage for example of 5 V, in turn connected to a controlled switch 1 5.
The output of the controlled switch 1 5 is connected to and supplies a light emitter 20, for example infrared , which is located inside the probe, a first receiver 21 of the light emitted by the device and reflected by the suspended particles , a second control receiver 22 of the infrared lig ht reflected and if necessary a temperatu re sensor 23.
The capacitor 1 3 is also connected to a voltage regulator 25 wh ich supplies a voltage for example of 4.5 V to a microprocessor 26.
The microprocessor 26 is connected to an interface circuit 27 for analogy retransmission of the electrical signal proportional to the turbidity value measured .
The microprocessor 26 is fu rther connected to a digital interface circuit 28 wh ich , if necessary, allows the probe to communicate with the outside world via GSM , Bluetooth, RS485 protocols, etc.
The interface 28 can be used to programme and/or calibrate the probe itself.
The microprocessor controls and manages all the electronic circuit just described .
In particular, it manages the opening and closing of the controlled switch 15.
The electronic circuits are not further described as they are known to an expert in the sector.
The operation of the invention is evident to a person skilled in the art from the above description and particularly in the following.
During installation , calibration of the probe is performed in a known way and in this phase it is assumed that the energy necessary to correctly supply all the circuits is available.
In the operating phase the probe is supplied by a battery and therefore the electronic circuits must have a low consumption.
The microprocessor 26 is programmed so as to periodically perform measurement of the turbidity and therefore remain in rest mode and with the switch 15 open so as not to supply the circuits 20-23 for a predetermined time, which in the example is 8 seconds.
It then becomes active again, performs initialization of the circu its and closes the switch 1 5, supplying the circu its 20-23, and performs the measurement accord ing to known methods, in a time which according to the embodiment example is 50 ms.
It processes the measurements performed and sends to the interface 27 an electrical signa l in Volts proportional to the value of the measurement.
A measurement acquisition device like a datalogger or a GSM card which will send the values to their destination can be applied to the interface 28.
The measurement cycle is then repeated .
The switch 1 5 remains closed for approximately 50 ms, during the measurement phase and remains open for 8 s, to recharge the capacitor 1 3.
The turbid ity measurement is then repeated periodically every 8 s.
Other measurement period icity values can be used and consequently the most appropriate value for the capacitor 1 3 must also be determ ined , so that it has time to be recharged and is able to supply the current requi red for the measurement without the voltage value at its ends d ropping below a pre-established value (for example 5.2 V) .
The presence of the voltage regu lators 1 1 , 14 and 25 is preferable in order to ensure a constant power supply voltage that does not vary with variation in the voltage at the ends of the capacitor 1 3 or with variation in the voltage of the battery 1 0.
The mean energy absorption from the power supply source 1 0 is lower than 1 mA and equal to approximately 0.7-0.8 mA, although during the measurement period the current supplied by the capacitor can even be equal to 25- 30 mA, in particular d uring activation of the lig ht transmitter 20 (for approximately 5 ms only) .
The initial voltage of approximately 5.8 V at the ends of the capacitor 1 3 d uring the measurement period decreases but the charging time of the capacitor 1 3 and the measurement time have been calculated so that it never d rops below approximately 5.2 V. With this voltage, the voltage regulator 25 is able to supply a voltage of 4.5 V to the microprocessor 26.
The microprocessor 26 is connected upstream of the switch 1 5 and is therefore always supplied by the capacitor 1 3.
The presence of the current limiter 1 2 means that the current consumption is limited to a maximum value which in the embodiment example is 1 mA.
The electronic circuits present are therefore supplied by the capacitor 1 3 without further absorption of energy from the supply sou rce 1 0 with the exception of the supply of 1 mA maximum.
The electronic circuits may be produced in any way according to requirements and the state of the art.
The circuit conceived as above is subject to numerous modifications and variations, all falling within the inventive concept; furthermore, all the details can be replaced by technically equivalent elements.

Claims

1 . A probe for measuring turbid ity, h igh tu rbid ity and/or suspended solids at low consumption , comprising : a power source, connected to a current l im iter that supplies at least one capacitor connected to ground ; said cu rrent limiter limits the current at its output to a maximum cu rrent of 1 mA; said at least one capacitor is connected to a controlled switch , which is in tu rn connected to an electron ic circuit for measuring tu rbid ity and suspended solids; comprising a microprocessor which period ically opens said switch for a first predetermined time to recharge said at least one capacitor, and which period ically closes said switch for a second predetermined time to perform said measurement of turbid ity and suspended solids; said electronic circuit for measuring the turbidity and/or suspended solids comprises a light emitter, a first receiver of the infrared light reflected by the suspended particles, and a second control receiver of the infrared light reflected .
2. A probe accord ing to claim 1 , characterised in that it comprises a first voltage reg ulator between said power source and said current limiter.
3. A probe accord ing to one of the preceding claims, characterised in that it comprises a second voltage regulator between said at least one capacitor and said controlled switch .
4. A probe accord ing to one of the preceding claims, characterised in that it comprises a second voltage regulator between said at least one capacitor and said m icroprocessor.
5. A probe accord ing to one of the preced ing claims, characterised in that said microprocessor is supplied by said at least one capacitor.
6. A probe according to one of the preceding claims, characterised in that said electronic circuit for measuring turbid ity and/or suspended solids comprises a temperature sensor.
7. A probe accord ing to one of the preceding claims, characterised in that said first predetermined time is g reater than said second predetermined time.
8. A probe accord ing to one of the preced ing claims, characterised in that it comprises an interface used to read the values measured by said probe and to prog ramme and/or calibrate said probe.
9. A method for measuring turbidity, high turbid ity and/or suspended solids, comprising the steps of: supplying a power to at least one capacitor by means of a current limiter, which limits the current at its output to a maximum current of 1 mA; charg ing said at least one capacitor for a first predetermined time period ; supplying an electronic circuit for measuring turbid ity and suspended solids by means of said capacitor for a second predetermined time; sending an infrared lig ht, receiving the infrared lig ht reflected by the suspended particles, and receiving the control infrared light reflected .
PCT/IB2017/050299 2016-01-27 2017-01-20 Probe for measuring turbidity, high turbidity and/or suspended solids at low consumption WO2017130085A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT102016000008135 2016-01-27
ITUB2016A000515A ITUB20160515A1 (en) 2016-01-27 2016-01-27 PROBE FOR MEASURING TORBIDITY, HIGH TORBIDITY AND / OR LOW CONSUMPTION SUSPENDED SOLIDS.

Publications (1)

Publication Number Publication Date
WO2017130085A1 true WO2017130085A1 (en) 2017-08-03

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3480784A (en) * 1967-02-13 1969-11-25 Sweden Freezer Mfg Co Absorption tester having ports and trapezoidal enclosure with provision for eliminating bubbles from the optical test path
US3946241A (en) * 1973-11-26 1976-03-23 Pyrotector, Incorporated Light detector with pulsed light source and synchronous data gating
JPH06174504A (en) * 1992-12-04 1994-06-24 Toshiba Corp Magnetic detection circuit
US20050264817A1 (en) * 2004-05-27 2005-12-01 Envision Instruments, Llc Systems and methods for in situ spectroscopic measurements
EP2653857A2 (en) * 2012-04-19 2013-10-23 Hydrometer GmbH Turbidity sensor and flow meter for fluid

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3480784A (en) * 1967-02-13 1969-11-25 Sweden Freezer Mfg Co Absorption tester having ports and trapezoidal enclosure with provision for eliminating bubbles from the optical test path
US3946241A (en) * 1973-11-26 1976-03-23 Pyrotector, Incorporated Light detector with pulsed light source and synchronous data gating
JPH06174504A (en) * 1992-12-04 1994-06-24 Toshiba Corp Magnetic detection circuit
US20050264817A1 (en) * 2004-05-27 2005-12-01 Envision Instruments, Llc Systems and methods for in situ spectroscopic measurements
EP2653857A2 (en) * 2012-04-19 2013-10-23 Hydrometer GmbH Turbidity sensor and flow meter for fluid

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