CN206114509U - Turbid measuring device of dualbeam wide -range based on modulated light source - Google Patents
Turbid measuring device of dualbeam wide -range based on modulated light source Download PDFInfo
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- CN206114509U CN206114509U CN201621192813.6U CN201621192813U CN206114509U CN 206114509 U CN206114509 U CN 206114509U CN 201621192813 U CN201621192813 U CN 201621192813U CN 206114509 U CN206114509 U CN 206114509U
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Abstract
The utility model discloses a turbid measuring device of dualbeam wide -range based on modulated light source, transconductance amplifier, ac coupling ware and synchronous Rectifier wave filter, a high accuracy AD collector of corresponding including singlechip, reference source, double knives single -throw switch, constant -current drive circuit, LED light source, two photoelectric detector, with each photoelectric detector. The singlechip produces frequency square signal, is used for controlling double knives single -throw switch to combine constant -current drive circuit, modulate frequency square signal on the LED light source, can guarantee that LED luminous is stable, and the modulation light that makes the LED light source produce corresponding frequency, can distinguish mutually with the direct current light of nature, can eliminate environment light and disturb and the produced measuring error of low -frequency noise, the adoption is placed two photoelectric detector on not equidirectional and is absorbed the light beam on not equidirectional, adopts the dualbeam can realize the turbidity of wide -range and measures.
Description
Technical field
This utility model is related to sensor technical field, and in particular to a kind of dual-beam wide-range turbidity of modulated light source is surveyed
Amount device.
Background technology
At present turbidity transducer is basic according to the standards of EN ISO 7027, i.e., in the internal LED for placing a 860nm of probe,
The light source that the LED sends is placing a light electrical resistivity survey after the particle in sample positioned at the direction in 90 ° with incident illumination
Device is surveyed, the turbidity value through being calculated testing liquid.
But most of turbidity suspension sensor on the market adopts direct current light modulation, straight using photodetector
Direct current optical signal is received, so as to calculate the turbidity of testing liquid.Can there is problems with using this direct current light modulation：1. hold
Being vulnerable to the interference of external environmental light causes measurement error, is 2. easily subject to the interference of external electromagnetic noise to cause measurement error.
It is big using the serious measurement error of the drift of the turbidity transducer of the method, it is impossible to use under natural environment.And it is exhausted on the market
Most turbidity is most to adopt single beam technology, i.e., only with 90 ° of scattered lights, by the scattered color feature of light, the method is only
Can use in lower range scope for example：0-1000NTU, cannot use in high range or measured deviation is larger.
Utility model content
This utility model provides a kind of dual-beam wide-range turbidity meter based on modulated light source, it is possible to increase treat
Survey the degree of accuracy of liquid turbidity measurement.
The technical scheme that this utility model solves above-mentioned technical problem is as follows：There is provided a kind of double light based on modulated light source
Beamwidth range turbidity meter, including single-chip microcomputer, a reference source, double-pole single throw, constant-current drive circuit, LED light source, two
Photodetector trsanscondutance amplifier corresponding with each photodetector, ac-coupled device and synchronous rectification wave filter, one
High-precision AD harvester；
The single-chip microcomputer is electrically connected with the first end of the double-pole single throw, the second end of the double-pole single throw
A reference source or ground connection are connected respectively by switching, the 3rd end of the double-pole single throw is connected by constant-current drive circuit
LED light source, first photodetector is placed on the position with the incident light direction of LED light source into the 90 ° of directions in space, second
Photodetector is placed on the position with the incident light direction of LED light source into the 135 ° of directions in space, first photodetector and
Second photodetector sequentially pass through respectively corresponding trsanscondutance amplifier, ac-coupled device and synchronous rectification wave filter with it is high-precision
The corresponding acquisition channel connection of degree AD harvesters, the high-precision AD harvester is connected with the single-chip microcomputer.
The beneficial effects of the utility model are：Single-chip microcomputer produces frequency square wave signal, controls double-pole single throw, and combines
Constant-current drive circuit, by frequency square wave signal modulation on LED light source, can guarantee that LED light source stable luminescence, and cause LED light
Source produces the modulation light of corresponding frequencies, can mutually distinguish with the direct current light of nature, can eliminate ambient light interference and low-frequency noise
Produced measurement error；The light beam on different directions is absorbed using two photodetectors placed in different directions, is adopted
The turbidimetry of wide-range can be realized with dual-beam.
On the basis of above-mentioned technical proposal, this utility model can also make following improvement.
Further, the LED light source is the light source for a length of 860nm of light wave.
Further, also including power module, the power module is powered for each electronic component.
Description of the drawings
Fig. 1 connects block diagram for a kind of dual-beam wide-range turbidity meter based on modulated light source of embodiment 1；
Fig. 2 is the spatial relation between LED light source and photodetector.
In accompanying drawing, the title representated by each label is as follows：
1st, LED light source, 2, the incident light direction of LED light source, 3, the locus of photodetector.
Specific embodiment
Principle of the present utility model and feature are described below in conjunction with accompanying drawing, example is served only for explaining this practicality
It is new, it is not intended to limit scope of the present utility model.
Embodiment 1,
Referring to Fig. 1, the dual-beam wide-range turbidity meter based on modulated light source that the present embodiment is provided includes monolithic
Machine, a reference source, double-pole single throw, constant-current drive circuit, LED light source, two photodetectors and each photodetector
Corresponding trsanscondutance amplifier, ac-coupled device and synchronous rectification wave filter, a high-precision AD harvester；
The single-chip microcomputer is electrically connected with the first end of the double-pole single throw, the second end of the double-pole single throw
A reference source or ground connection are connected respectively by switching, the 3rd end of the double-pole single throw is connected by constant-current drive circuit
LED light source, first photodetector is placed on the position with the incident light direction of LED light source into the 90 ° of directions in space, second
Photodetector is placed on the position with the incident light direction of LED light source into the 135 ° of directions in space, first photodetector and
Second photodetector sequentially pass through respectively corresponding trsanscondutance amplifier, ac-coupled device and synchronous rectification wave filter with it is high-precision
The corresponding acquisition channel connection of degree AD harvesters, the high-precision AD harvester is connected with the single-chip microcomputer.
Wherein, the LED light source is the light source for a length of 860nm of light wave.
The operation principle of the dual-beam wide-range turbidity meter based on modulated light source provided using this utility model
For：Single-chip microcomputer produces square wave of the frequency for F, and the square wave is used for controlling double-pole single throw.When the frequency that single-chip microcomputer is produced
For F square wave be high level when, double-pole single throw connects a reference source, and a reference source to constant-current drive circuit input DC power makes
LED light source lights；When single-chip microcomputer produce frequency for F square wave be low level when, double-pole single throw ground connection, LED light source without
Method lights.Using double-pole single throw and constant-current drive circuit, can by the frequency for F square-wave frequency modulation on LED light source, make
LED light source stable luminescence is ensure that with modulated light source and constant-current drive circuit, it is possible to produce the modulation that a frequency is F
Light, the ac modulation light of the frequency can mutually be distinguished with the direct current light of nature, can eliminate ambient light interference and low-frequency noise institute
The measurement error of generation, drifts about low, and turbidimetry error is low.When the modulation illumination is mapped to the particle contained by testing liquid,
Scattered light can be produced.It is the spatial relation between LED light source and photodetector referring to Fig. 2.1 represents LED light in Fig. 2
The position in source, 2 represent the direction of LED light source incident particles, and 3 represent the locus of photodetector, and the angle, θ in figure is light
Space angle between electric explorer and the incident light direction of LED light source.Wherein, the first photodetector is placed on and LED light
Into the position in the 90 ° of directions in space, second photodetector be placed on the incident light direction with LED light source to the incident light direction in source
Into the position in the 135 ° of directions in space.
During liquid turbidity is measured, when the light beam of directive medium runs into light tight granule, for example, solid particle,
Light beam is referred to as scattering of light by the original direction of propagation, this phenomenon is changed.When concentration of solid particles in medium is relatively low, big portion
The tight 90 ° of directions scattering of light splitter, the scattered light for scattering on light direction afterwards is less；Conversely, the concentration of solid particles in medium is higher
When, most of light is scattered along rear scattering light direction, and the scattered light on 90 ° of directions is less.Thus, it is possible to obtain optimal turbidity
Measurement result：When low turbidity is measured, generally using 90 ° of scattering photo measures；When middle and high turbidity and suspended sediment concentration are measured, adopt
With rear scattering photo measure.The rear scattered light adopted in the present embodiment is for 135 °.
First photodetector receives the scattered light on 90 ° of directions, and the second photodetector receives dissipating on 135 ° of directions
Light is penetrated, the modulated optical signal that the first photodetector and the second photodetector are received passes through respectively corresponding trsanscondutance amplifier
Modulated photocurrent signal is become into voltage signal, this two-way voltage signal acts on corresponding after corresponding ac-coupled device
Synchronous rectification wave filter.The d. c. voltage signal of prime can be carried out intercepting and only retained and modulating light frequency F by ac-coupled device
Identical ac voltage signal is so as to solving the interference of natural light and the measurement error of low-frequency noise.Due to 90 ° received
Scattered light signal and 135 ° of scattered light signal be square wave AC signal, corresponding synchronous rectification wave filter believes square wave alternating-current
Number it is changed into direct current signal, and the peak value of the height of direct current signal and the square-wave signal is directly proportional.First synchronous rectification is filtered
The direct current signal of two angle scattered lights that device and the second synchronous rectification wave filter are obtained passes through two of high-precision AD harvester
Channel acquisition, due to the size of the size direct reaction turbidity of direct current signal, single-chip microcomputer collects the two of high-precision AD harvester
The voltage of road direct current signal is so as to conversing corresponding turbidity.In lower range 0-1000NUT, using 90 ° of scattered light conducts
The data of liquid turbidity measurement, in middle high range 1000-4000NUT, are measured using 135 ° of scattered lights as liquid turbidity
Data, it is possible to achieve the turbidimetry of wide-range.
A kind of dual-beam wide-range turbidity meter based on modulated light source that this utility model is provided, single-chip microcomputer is produced
Frequency square wave signal, for controlling double-pole single throw, and combines constant-current drive circuit, by frequency square wave signal modulation in LED
On light source, LED light source stable luminescence is can guarantee that, and cause LED light source to produce the modulation light of corresponding frequencies, the modulation light is exchange
Modulation light, can mutually distinguish with the direct current light of nature, can eliminate ambient light interference and the measurement error produced by low-frequency noise；
The light beam on different directions is absorbed using two photodetectors placed in different directions, width can be realized using dual-beam
The turbidimetry of range.
Preferred embodiment of the present utility model is the foregoing is only, it is all in this practicality not to limit this utility model
Within new spirit and principle, any modification, equivalent substitution and improvements made etc. should be included in guarantor of the present utility model
Within the scope of shield.
Claims (3)
1. a kind of dual-beam wide-range turbidity meter based on modulated light source, it is characterised in that including single-chip microcomputer, benchmark
Source, double-pole single throw, constant-current drive circuit, LED light source, two photodetectors are corresponding with each photodetector
Trsanscondutance amplifier, ac-coupled device and synchronous rectification wave filter and a high-precision AD harvester；
The single-chip microcomputer is electrically connected with the first end of the double-pole single throw, and the second end of the double-pole single throw passes through
Switching connects respectively a reference source or ground connection, and the 3rd end of the double-pole single throw connects LED light by constant-current drive circuit
Source, the LED light source goes out light irradiation testing liquid granule, and first photodetector is placed on the incident illumination with LED light source
Into the position in the 90 ° of directions in space, second photodetector be placed on the incident light direction of LED light source into 135 ° of space in direction
The position in direction, first photodetector and second photodetector sequentially pass through respectively corresponding trsanscondutance amplifier, friendship
Stream bonder and synchronous rectification wave filter connect to the corresponding acquisition channel of high-precision AD harvester, the high-precision AD harvester
It is connected with the single-chip microcomputer.
2. the dual-beam wide-range turbidity meter of modulated light source is based on as claimed in claim 1, it is characterised in that described
LED light source is the light source for a length of 860nm of light wave.
3. the dual-beam wide-range turbidity meter of modulated light source is based on as claimed in claim 1, it is characterised in that also wrapped
Power module is included, the power module is powered for each electronic component.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621192813.6U CN206114509U (en) | 2016-10-28 | 2016-10-28 | Turbid measuring device of dualbeam wide -range based on modulated light source |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201621192813.6U CN206114509U (en) | 2016-10-28 | 2016-10-28 | Turbid measuring device of dualbeam wide -range based on modulated light source |
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| CN206114509U true CN206114509U (en) | 2017-04-19 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110887793A (en) * | 2018-09-10 | 2020-03-17 | 中国石油化工股份有限公司 | Modulation wave driving type precision photoelectric detector |
| CN115046939A (en) * | 2022-05-30 | 2022-09-13 | 武汉新烽光电股份有限公司 | Throw-in type turbidity sensor and detection method thereof |
| CN115808389A (en) * | 2022-12-23 | 2023-03-17 | 山东仁科测控技术有限公司 | Anti-interference suspended matter detection method and detection device |
-
2016
- 2016-10-28 CN CN201621192813.6U patent/CN206114509U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110887793A (en) * | 2018-09-10 | 2020-03-17 | 中国石油化工股份有限公司 | Modulation wave driving type precision photoelectric detector |
| CN115046939A (en) * | 2022-05-30 | 2022-09-13 | 武汉新烽光电股份有限公司 | Throw-in type turbidity sensor and detection method thereof |
| CN115808389A (en) * | 2022-12-23 | 2023-03-17 | 山东仁科测控技术有限公司 | Anti-interference suspended matter detection method and detection device |
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