CN112985585B

CN112985585B - Calibration method and calibration system for standard light source and photometer

Info

Publication number: CN112985585B
Application number: CN202110143375.3A
Authority: CN
Inventors: 喻骏; 南永涛
Original assignee: Shanghai Yilexi Technology Co ltd
Current assignee: Shanghai Yilexi Technology Co ltd
Priority date: 2021-02-02
Filing date: 2021-02-02
Publication date: 2023-02-03
Anticipated expiration: 2041-02-02
Also published as: CN112985585A

Abstract

The embodiment of the invention provides a calibration method and a calibration system for a standard light source and a photometer, and relates to the technical field of testing. A standard light source, comprising: the light-emitting circuit and the control circuit are connected with each other; the light-emitting circuit comprises two light-emitting light sources; the control circuit is used for controlling each light-emitting light source in the light-emitting circuit to emit light with set light intensity according to the received control signal. According to the invention, a standard light source comprising two light-emitting light sources can be used for carrying out calibration test on the photometer to be calibrated, even if the light intensity exceeds a certain pulse rate, the photometer can still be accurately calibrated, and the accuracy of calibration is ensured to a certain extent; in addition, the photometers with different electrical characteristics can be calibrated in a targeted manner, so that the photometers with different electrical characteristics can be guaranteed to have better calibration accuracy.

Description

Calibration method and calibration system for standard light source and photometer

Technical Field

The invention relates to the technical field of testing, in particular to a calibration method and a calibration system for a standard light source and a photometer.

Background

Photons are the fundamental particles that transmit electromagnetic interactions, a canonical boson. Photons are carriers of electromagnetic radiation, whereas in quantum-field theory photons are considered as mediators of electromagnetic interactions. The stationary mass of a photon is zero compared to most elementary particles, which means that its propagation speed in vacuum is the speed of light. Like other quanta, photons have a wave-particle duality that can exhibit properties such as refraction, interference, diffraction, etc. of classical waves, while the particle nature of photons exhibits interactions with matter, and photons can only transmit quantized energy. For visible light, the energy carried by a single photon is about 4 × 10 ^-19 Joule, an amount of energy sufficient to excite a molecule of a photoreceptor cell on the eye, thereby causing vision. In addition to energy, a photon also has momentum and polarization state, but a single photon does not have a defined momentum or polarization state.

At present, a commonly used photon detection method is to detect a light signal by a photometer, because the photometer has the highest linear pulse rate, an electronic overlapping phenomenon in the photometer occurs after the photon flow exceeds the highest linear pulse rate, so that the linear pulse rate is bent and changed, the pulse rate of the real corresponding light intensity cannot be detected at the moment, the test value of the pulse rate is smaller than the real value of the pulse rate, and the real value can be obtained by calibrating the test value by adopting a linearity regression calibration algorithm at the moment.

However, when the linearity regression calibration is used to calibrate the test value, if the pulse rate corresponding to the light intensity exceeds 20M/s, the calibration accuracy cannot be guaranteed, and the electrical characteristics of each type of photometer are different, so that the photometers of different types cannot be calibrated in a targeted manner.

Disclosure of Invention

The invention aims to provide a standard light source, a calibration method of a photometer and a calibration system, which can be used for calibrating and testing the photometer to be calibrated by using the standard light source comprising two light-emitting light sources, can still accurately calibrate the photometer even if the light intensity exceeds a certain pulse rate, and can ensure the accuracy of calibration to a certain extent; in addition, the photometers with different electrical characteristics can be calibrated in a targeted manner, so that the photometers with different electrical characteristics can be guaranteed to have better calibration accuracy.

To achieve the above object, the present invention provides a standard light source, comprising: the light-emitting circuit and the control circuit are connected with each other; the light-emitting circuit comprises two light-emitting light sources; the control circuit is used for controlling each light-emitting light source in the light-emitting circuit to emit light with set light intensity according to the received control signal.

The invention also provides a method for calibrating the photometer, which comprises the following steps: independently controlling each of two light-emitting light sources in the standard light source to emit light rays with corresponding reference intensity towards a photometer to be calibrated, so that the count value of the photometer is a preset reference value; performing multiple calibration tests on the photometer based on the reference intensity corresponding to each light-emitting source to obtain the corresponding relation between the theoretical value and the test value of the pulse rate of the photometer; the process of calibrating the test includes: controlling one of the two light-emitting sources to emit light with current test intensity towards the photometer and controlling the other light-emitting source to emit light with corresponding reference intensity towards the photometer so as to obtain a current test value of the photometer; and controlling a light emitting source to emit light towards the photometer, so that the luminosity counting value is the current test value, reading the target intensity of the light emitted by the light emitting source, and performing the next round of calibration test on the photometer by taking the target intensity as the current test intensity.

The present invention also provides a system for calibrating a photometer, comprising: the standard light source and the calibration device; the calibration equipment is respectively connected with the standard light source and the photometer to be calibrated; the calibration device is used for executing the calibration method of the photometer, and the photometer is calibrated by using the standard light source.

Compared with the prior art, the invention provides a standard light source for calibrating a photometer, which comprises a light-emitting circuit and a control circuit which are connected with each other, wherein the light-emitting circuit comprises two light-emitting light sources, and when the photometer is calibrated, the control circuit can control each light-emitting light source in the light-emitting circuit to emit light with set light intensity according to a received control signal, so that photometers with different electrical characteristics can be calibrated respectively in a targeted manner by using the standard light source, and the corresponding relation between the theoretical value and the test value of the pulse rate of each photometer is obtained, thereby ensuring that the photometers with different electrical characteristics all have better calibration accuracy; and even if the light intensity exceeds a certain pulse rate, the photometer can still be accurately calibrated.

In one embodiment, the standard light source further comprises a power supply circuit connected to the light emitting circuit and the control circuit, respectively; the power supply circuit is used for supplying power to the light-emitting light source and the control circuit in the light-emitting circuit.

In one embodiment, the light emitting circuit includes a first light source, a first triode, a first current limiting resistor, a second light source, a second triode, a second current limiting resistor, and a signal conversion module; the first end of the first light source is connected to a power supply, the second end of the first light source is connected to a collector of the first triode, the first end of the second light source is connected to the power supply, the second end of the second light source is connected to a collector of the second triode, the input end of the signal conversion module is connected to the control circuit, the first output end of the signal conversion module is connected to a base of the first triode, the second output end of the signal conversion module is connected to a base of the second triode, an emitter of the first triode is connected to a reference potential end through a first current-limiting resistor, and an emitter of the second triode is connected to the reference potential end through a second current-limiting resistor; the control circuit is used for sending a corresponding light source adjusting signal to the signal conversion module according to the received control signal; the signal conversion module is used for outputting a first voltage signal to the first light source and outputting a second voltage signal to the second light source according to the received light source adjusting signal.

In one embodiment, the signal conversion module includes: an operational amplifier and an analog-to-digital converter; the input end of the analog-to-digital converter is connected with the control circuit; the first output end of the analog-to-digital converter is connected to the first positive input end of the operational amplifier, the second output end of the analog-to-digital converter is connected to the second positive input end of the operational amplifier, the first negative input end of the operational amplifier is connected to the emitter of the first triode, the second negative input end of the operational amplifier is connected to the emitter of the second triode, the first output end of the operational amplifier is connected to the base of the first triode, and the second output end of the operational amplifier is connected to the base of the second triode; the control circuit is used for sending a corresponding light source adjusting signal to the analog-to-digital converter according to the received control signal; the analog-to-digital converter is used for respectively outputting corresponding analog voltage signals to a first positive input end and a second positive input end of the operational amplifier after receiving the light source adjusting signal; the operational amplifier is used for outputting a first voltage signal to the first light source according to the analog voltage signal received by the first positive input end; the operational amplifier is used for outputting a second voltage signal to the second light source according to the analog voltage signal received by the second positive input end.

In one embodiment, the light emitting circuit further comprises: the double-path digital potentiometer comprises a first adjustable resistor and a second adjustable resistor; the input end of the two-way digital potentiometer is connected with the control circuit, the first adjustable resistor is connected with the first current-limiting resistor in parallel, and the second adjustable resistor is connected with the second current-limiting resistor in parallel; the two-way digital potentiometer is used for respectively adjusting the resistance value of the first adjustable resistor and the resistance value of the second adjustable resistor according to the resistance value adjusting signal when receiving the resistance value adjusting signal sent by the control circuit.

In one embodiment, the light emitting circuit further comprises: a first analog switch and a second analog switch; the first end of the first light source is connected to a power supply through a first analog switch, and the first end of the second light source is connected to the power supply through a second analog switch; the control circuit is respectively connected with the control end of the first analog switch and the control end of the second analog switch; the control circuit is used for respectively controlling the on and off of the first analog switch and the second analog switch.

In one embodiment, a power supply circuit includes: the power supply comprises a battery pack, a booster circuit, a first voltage stabilizing circuit and a second voltage stabilizing circuit; the battery pack is connected to the input end of the booster circuit, the output end of the booster circuit is respectively connected to the input ends of the first voltage stabilizing circuit and the second voltage stabilizing circuit, and the output end of the first voltage stabilizing circuit and the output end of the second voltage stabilizing circuit are respectively connected to the light-emitting circuit and the control circuit; the boosting circuit is used for boosting a voltage signal output by the battery pack to a first preset voltage; the first voltage stabilizing circuit is used for stabilizing the voltage signal of the first preset voltage to a second preset voltage; the first voltage stabilizing circuit is used for stabilizing the voltage signal of the first preset voltage to a third preset voltage.

In one embodiment, the control circuit is further connected to the output terminal of the boost circuit; the control circuit is used for controlling each light-emitting light source in the light-emitting circuit to stop emitting light when the voltage of the voltage signal output by the booster circuit is lower than a fourth preset voltage.

In one embodiment, the power supply circuit further comprises a power supply female socket and a selection switch; the battery pack is connected with a first input end of the selector switch, the power supply female socket is connected with a second input end of the selector switch, an output end of the selector switch is connected with the booster circuit, and the control circuit is connected with a control end of the selector switch; the control circuit is also used for controlling the output end of the selection switch to be conducted with the first input end or the second input end of the selection switch.

In one embodiment, after performing multiple calibration tests on the photometer with the reference intensity as the initial test intensity to obtain the corresponding relationship between the theoretical value and the test value of the pulse rate of the photometer, the method further includes: establishing a calibration formula of a target test value between adjacent test values based on the corresponding relation between the theoretical value and the test value, wherein the calibration formula is as follows: y = (a-B) × (B ' -C ')/(B-C) + C '; wherein Y represents a calibrated theoretical value, A represents a target test value to be calibrated, B represents one test value of adjacent test values, C represents the other test value of the adjacent test values, C is more than A and less than B, B 'represents a theoretical value corresponding to the test value B, and C' represents a theoretical value corresponding to the test value C.

In one embodiment, the theoretical values of the photometer during each round of calibration test are: and (N + 1) K, where K is a preset reference value and N is the current number of calibration tests.

In one embodiment, the standard light source faces the photometer, and the light receiving diameter of the photometer is equal to 2 times the distance between the two light emitting sources.

In one embodiment, the distance between the standard light source and the photometer is (D1/2) × ot (θ/2), wherein D1 represents the distance between the two luminescent light sources and θ represents the effective luminescent angle of the luminescent light source.

Drawings

FIG. 1 is a block schematic diagram of a standard light source in a first embodiment according to the present invention;

FIG. 2 is a schematic diagram of the connection of a standard light source to a photometer and calibration device according to a first embodiment of the present invention;

FIGS. 3 and 4 are block schematic diagrams of a standard light source according to a second embodiment of the present invention;

FIG. 5 is a circuit configuration diagram of a power supply circuit of a standard light source according to a second embodiment of the present invention;

FIG. 6 is a schematic diagram of a light emitting circuit in a third embodiment in accordance with the invention;

fig. 7 is a circuit configuration diagram of a light emitting circuit according to a third embodiment of the present invention;

fig. 8 is a circuit configuration diagram of a control circuit according to a third embodiment of the present invention;

FIG. 9 is a detailed flow chart of a method of calibrating a photometer according to a fourth embodiment of the present invention;

FIG. 10 is a schematic view of the position of a photometer and a standard light source in a method of calibrating a photometer according to a fourth embodiment of the present invention;

FIG. 11 is a schematic diagram of a multi-round calibration test of a photometer according to a fourth embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The objects, features and advantages of the present invention will be more clearly understood from the following detailed description of various embodiments of the present invention taken in conjunction with the accompanying drawings. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are merely intended to illustrate the spirit of the technical solution of the present invention.

In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. One skilled in the relevant art will recognize, however, that an embodiment can be practiced without one or more of the specific details. In other instances, well-known devices, structures and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Throughout the specification and claims, the word "comprise" and variations thereof, such as "comprises" and "comprising," are to be understood as an open, inclusive meaning, i.e., as being interpreted to mean "including, but not limited to," unless the context requires otherwise.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and/or" unless the context clearly dictates otherwise.

In the following description, for the purposes of clearly illustrating the structure and operation of the present invention, directional terms will be used, but terms such as "front", "rear", "left", "right", "outer", "inner", "outer", "inward", "upper", "lower", etc. should be construed as words of convenience and should not be construed as limiting terms.

A first embodiment of the present invention relates to a standard light source for calibrating a photon measuring instrument such as a photometer (spectrophotometer), for example, a photometer using a Photomultiplier Tube (PMT). Referring to fig. 1 and fig. 2, a standard light source 10 in the present embodiment includes: the present embodiment and the following embodiments are described by taking two light emitting sources including a first light source a and a second light source B as an example, where the light emitting circuit 1 and the control circuit 2 are connected to each other, and the light emitting circuit 1 includes two light emitting sources (for example, LED light sources).

The control circuit 2 is used for controlling each light-emitting light source in the light-emitting circuit 1 to emit light with set light intensity according to the received control signal. Specifically, when the photometer 20 is calibrated, the control circuit 2 may be connected to an external calibration device 30 (e.g., a laptop, a mobile phone, a tablet pc, etc.) through a wired (e.g., a USB connection line) or wireless (bluetooth, WIFI) connection manner, the calibration device may send a control signal to the control circuit 2, the control circuit 2 obtains the light intensities of the first light source a and the second light source B based on the control signal, and controls the first light source a and the second light source B in the light emitting circuit 1 to emit light of a set light intensity toward the photometer 20, the photometer 20 may receive the light emitted by the first light source a and the second light source B, the calibration device 30 may obtain a pulse rate detected by the photometer 20, and calibrate the pulse rate detected by the photometer 20, so as to obtain a corresponding relationship between a theoretical value and a test value of the pulse rate of the photometer 20.

In fig. 2, two light-emitting sources may be arranged in a circular area, the two light-emitting sources are symmetrical about the center of a circle, and a circuit portion (including a light-emitting circuit and a control circuit) is arranged in a square area, so that it is possible to prevent a driving current input to the light-emitting sources from being interfered by a self circuit, and a black solder resist layer is adopted in a PCB design of the circuit portion, reducing stray light reflection on an ineffective light path. It should be noted that, the shape of the standard light source 10 is only schematically shown in fig. 2, and the shape of the standard light source 10 may be set according to actual requirements.

Compared with the prior art, the embodiment provides a standard light source for calibrating a photometer, the standard light source comprises a light emitting circuit and a control circuit which are connected with each other, the light emitting circuit comprises two light emitting sources, and when the photometer is calibrated, the control circuit can control each light emitting source in the light emitting circuit to emit light with set light intensity according to a received control signal, so that photometers with different electrical characteristics can be calibrated respectively in a targeted manner by using the standard light source, and the corresponding relation between the theoretical value and the test value of the pulse rate of each photometer is obtained, so that the photometers with different electrical characteristics can be guaranteed to have better calibration accuracy; and even if the light intensity exceeds a certain pulse rate, the photometer can still be accurately calibrated.

The second embodiment of the present invention designs a standard light source, and compared with the first embodiment, the present embodiment mainly differs in that: referring to fig. 3, the standard light source 10 further includes: and the power supply circuit 3 is connected with the light-emitting circuit 1 and the control circuit 2 respectively.

The power supply circuit 3 is used for supplying power to the light-emitting light source in the light-emitting circuit 1 and the control circuit 2.

Referring to fig. 4 and 5, the power supply circuit 3 includes: the battery pack 31, the booster circuit 32, and the first and second

constant voltage circuits

33 and 34. The battery pack 31 may be composed of serially connected lithium batteries, and a battery base is disposed in the power supply circuit 3 for installation and replacement of the lithium batteries.

The battery pack 31 is connected to an input terminal of the voltage boost circuit 32, an output terminal of the voltage boost circuit 32 is connected to input terminals of the first voltage stabilizing circuit 33 and the second voltage stabilizing circuit 34, respectively, and an output terminal of the first voltage stabilizing circuit 33 and an output terminal of the second voltage stabilizing circuit 34 are connected to the light emitting circuit 1 and the control circuit 2, respectively.

The boosting circuit 32 is used for boosting the voltage signal output by the battery pack 31 to a first preset voltage.

The first voltage regulator circuit 33 is configured to regulate a voltage signal of the first preset voltage to a second preset voltage.

The first voltage regulating circuit 34 is used for regulating the voltage signal of the first preset voltage to a third preset voltage.

In one example, the power supply circuit 3 further includes: the power supply female socket 35 may be a power supply interface (for example, a USB interface, a TYPE-C interface, etc.), and the power supply interface may be connected to an external high-capacity mobile power supply through a power supply data line to provide long-term power supply for the standard light source; the selection switch 36 may be a slide switch model SS-12D02-VG 4.

The battery pack 31 is connected to a first input terminal of the selection switch 36, the power supply female socket 35 is connected to a second input terminal of the selection switch 36, an output terminal of the selection switch 36 is connected to the voltage boost circuit 32, and the control circuit 2 is connected to a control terminal of the selection switch 36.

The control circuit 2 is further configured to control the output terminal of the selection switch 36 to be conductive with the first input terminal or the second input terminal of the selection switch 36.

In this embodiment, two power supply modes are provided for the standard light source: respectively supplying power to a battery pack 31 inside the standard light source or a mobile power supply outside the standard light source. Specifically, the battery pack 31 and the power supply base 35 are respectively connected to the selection switch 36, the control circuit 2 can control the power supply of the mobile power supply connected to the battery pack 31 or the power supply base 35 through on control of the selection switch 36, either one of the mobile power supply connected to the battery pack 31 and the power supply base 35 supplies power to the standard light source, and the standard light source cannot be powered on at the same time, so that the control circuit 2 can also control the standard light source to stop working by using the selection switch 36, that is, the input end and the output end of the selection switch 36 are controlled to be disconnected, and the light-emitting power supply in the light-emitting circuit 1 is in a power-off state at this time. In this embodiment, a mechanical switch of the selection switch 36 may be further disposed on the standard light source, so that the user can manually select to turn on or off the standard light source and switch the power supply mode of the standard light source.

Referring to fig. 5, in the present embodiment, the battery pack 31 includes two lithium batteries, and the boost circuit 32 includes: the boost chip 321, the inductor L1, the diode D1, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, and the TVS diode D2, and the first voltage Regulator circuit 33 and the second voltage Regulator circuit 34 are all Low Dropout regulators (LDOs) for achieving the purpose of voltage reduction and voltage regulation. Wherein, the TVS diode D2 is used to provide ESD protection.

A first terminal of the battery pack 31 is connected to a reference potential terminal GND, a second terminal of the battery pack 31 is connected to a first input terminal of the selection switch 36, a first terminal (VBUS port) of the power supply female socket 35 is connected to a second input terminal of the selection switch 36, a second terminal of the power supply female socket 35 is connected to the reference potential terminal GND, an output terminal of the selection switch 36 is connected to an input terminal IN of the boost chip 321 through an inductor L1, the input terminal IN of the boost chip 321 is connected to a first terminal of the TVS diode D2, and a second terminal of the TVS diode D2 is connected to the reference potential terminal GND; an enable terminal EN of the boost chip 321 for output voltage switch control is connected to an output terminal of the selection switch 36 through a first resistor R1, an output terminal of the selection switch 36 is connected to a reference potential terminal GND through a filter capacitor C1 (for example, a 1uF/25V capacitor), an output terminal of the selection switch 36 is further connected to a first terminal of a diode D1 through an inductor L1, an output terminal SW of the boost chip 321 is connected to a first terminal of the diode D1, a second terminal of the diode D2 is connected to a first terminal of a second resistor R2, a negative input terminal FB of the boost chip 321 for setting an output voltage is connected to a second terminal of the second resistor R2, the negative input terminal FB of the boost chip 321 is connected to the reference potential terminal GND through a third resistor R3 and a fourth resistor R4 connected IN series, and a second terminal of the diode D1 is further connected to an input terminal IN of the first voltage regulator circuit 33 and an input terminal IN of the second voltage regulator circuit 34, respectively; in addition, the pin NC of the boost chip 321 is suspended, and the ground pin GND of the boost chip 321, the ground pin GND of the first voltage stabilizing circuit 33, and the ground pin GND of the second voltage stabilizing circuit 34 are all connected to the reference potential end GND; the output terminal OUT of the first regulation circuit 33 and the output terminal OUT of the second regulation circuit 34 are both referenced to the potential terminal GND (for example, a 1uF/25V capacitor) through the filter capacitor C1.

In this embodiment, the resistance values of the second resistor R2, the third resistor R3, and the fourth resistor R4 are related to the magnitude of the input voltage and the magnitude of the output voltage of the boost chip 321, specifically, taking the battery pack 31 as an example of supplying power to a standard light source, the output voltage of a single lithium battery in the battery pack 31 is 3V, the output voltage of the first preset voltage set by the boost chip 321 is 6V, the maximum output voltage after two lithium batteries with output voltages of 3V are connected in series is 6V, and as the current of the lithium batteries is consumed, the output voltage of the battery pack 31 will be continuously reduced, the inductor L1 selects an inductor of 2.2uH/1.55A, the voltage of the negative input terminal FB of the boost chip 321 reaches stability when being 0.6V, at this time, the second resistor R2 is set to be a resistor of 220K ohm, the third resistor R3 is a resistor of 22.1K ohm, and the fourth resistor R4 is a resistor of 100 ohm; when the voltage at the negative input terminal FB of the boost chip 321 is 0.6V, the voltage VDD1= 0.6/(22.1 + 0.1) = 200+22.1+ 0.1) =6V output by the output terminal SW of the boost chip 321, that is, the boost circuit 32 stabilizes the voltage output by the battery pack 1 at 6V.

The voltages output by the first voltage stabilizing circuit 33 and the second voltage stabilizing circuit 34 can be set according to the requirement, and taking the power supply voltages required by the light emitting circuit 1 and the control circuit 2 include 5V and 3.3V as an example, the first voltage stabilizing circuit 33 is used for reducing and stabilizing the voltage signal of 6V into the voltage signal VDD2 of 5V, and the second voltage stabilizing circuit 33 is used for reducing and stabilizing the voltage signal of 6V into the voltage signal VDD3 of 3.3V.

In an example, taking the output voltage provided by the battery pack 1 as 4V, and the power supply voltages required by the light-emitting circuit 1 and the control circuit 2 include 5V and 3.3V, at this time, only one voltage-reducing and voltage-stabilizing circuit may be provided, the voltage-increasing circuit 32 increases the voltage signal of 4V output by the battery pack to 5V, the voltage of 5V output by the voltage-increasing circuit may be used to supply power to the light-emitting circuit 1 and/or the control circuit 2, and then the voltage-reducing and voltage-stabilizing circuit reduces the voltage signal of 5V to a voltage signal of 3.3V, and the voltage signal of 3.3V may also be used to supply power to the light-emitting circuit 1 and/or the control circuit 2.

Compared with the first embodiment, the power supply circuit is added in the standard light source, can supply power for the light-emitting circuit and the control circuit, and provides a specific circuit structure of the power supply circuit.

The third embodiment of the present invention relates to a standard light source, and compared with the second embodiment, the present embodiment mainly differs from the second embodiment in that: the embodiment provides a specific circuit structure of the light-emitting circuit in the standard light source.

Referring to fig. 6, the light emitting circuit 1 includes a first light source a (LEDA), a first transistor NPN1, a first current limiting resistor RA, a second light source B (LEDB), a second transistor NPN2, a second current limiting resistor RB, and a signal conversion module 11.

The first end of the first light source A is connected to a power supply, the second end of the first light source A is connected to a collector of a first triode NPN1, the first end of the second light source B is connected to the power supply, the second end B of the second light source is connected to a collector of a second triode NPN2, the input end of the signal conversion module 11 is connected to the control circuit 2, the first output end of the signal conversion module 11 is connected to a base of the first triode NPN1, the second output end of the signal conversion module 11 is connected to a base of the second triode NPN2, an emitter of the first triode NPN1 is connected to a reference potential end GND through a first current limiting resistor RA, and an emitter of the second triode NPN2 is connected to the reference potential end GND through a second current limiting resistor RB. In the present embodiment and the following embodiments, the power supply is taken as the power supply circuit 3 in the second embodiment as an example, and the standard light source includes the power supply circuit 3 in the second embodiment.

In one example, the light emitting circuit 1 further includes: the first end of the first light source a is connected to a power supply through the first analog switch 12, the first end of the second light source B is connected to the power supply through the second analog switch 13, that is, the power supply circuit 3 is connected to the first end of the first light source a through the first analog switch 12, and the power supply circuit 3 is connected to the first end of the second light source B through the second analog switch 13; the control circuit 2 is connected to the control terminal of the first analog switch 12 and the control terminal of the second analog switch 13, respectively.

The control circuit 2 is used for controlling the on and off of the first analog switch 12 and the second analog switch 13, respectively.

In one example, the light emitting circuit 1 further includes: the two-way digital potentiometer 14, wherein the two-way digital potentiometer 14 comprises a first adjustable resistor and a second adjustable resistor; the input end of the two-way digital potentiometer 14 is connected to the control circuit 2, the first adjustable resistor is connected in parallel with the first current limiting resistor RA, and the second adjustable resistor is connected in parallel with the second current limiting resistor RB.

The two-way digital potentiometer 14 is configured to adjust the resistance value of the first adjustable resistor and the resistance value of the second adjustable resistor according to the resistance value adjustment signal when receiving the resistance value adjustment signal sent by the control circuit 2.

In this embodiment, the signal conversion module 11 includes: an operational amplifier 111 and an analog-to-digital converter 112. The input end of the analog-to-digital converter 112 is connected to the control circuit 2; a first output end of the analog-to-digital converter 112 is connected to a first positive input end of the operational amplifier 111, a second output end of the analog-to-digital converter 112 is connected to a second positive input end of the operational amplifier 111, a first negative input end of the operational amplifier 111 is connected to an emitter of the first triode NPN1, a second negative input end of the operational amplifier 111 is connected to an emitter of the second triode NPN2, a first output end of the operational amplifier 111 is connected to a base of the first triode NPN1, and a second output end of the operational amplifier 111 is connected to a base of the second triode NPN 2.

The control circuit 2 is configured to send a corresponding light source adjustment signal to the analog-to-digital converter 112 according to the received control signal;

the analog-to-digital converter 112 is configured to output corresponding analog voltage signals to a first positive input end and a second positive input end of the operational amplifier 111 respectively after receiving the light source adjusting signal.

The operational amplifier 111 is configured to output a first voltage signal to the first light source a according to the analog voltage signal received by the first positive input terminal.

The operational amplifier 111 is configured to output a second voltage signal to the second light source B according to the analog voltage signal received by the second positive input terminal.

The following describes the light-emitting circuit 1 of fig. 7 in detail as an example.

The first analog switch 12 and the second analog switch 13 are analog switches of a BL1551 model, a power supply voltage of the analog switch of the BL1551 model is 5V, an enable end ENB (i.e., a control end) of the first analog switch 12 and the second analog switch 13 is connected to the control circuit 2, the enable end ENB is used for receiving an enable signal LEDA _ EN sent by the control circuit 2 and used for controlling on/off of the first light source a, an input end A1 and a power supply end VCC of the first analog switch 12 are connected to a voltage signal VDD2 output by a first voltage stabilizing circuit 33 in the power supply circuit 3, the input end A2 of the first analog switch 12 is suspended, an output end B of the first analog switch 12 is connected to a first end (i.e., an anode of the LEDA) of the first light source a, a cathode of the LEDA is connected to a collector of a first triode NPN1, and a ground end of the first analog switch 12 is connected to a GND reference potential end; the connection mode of each pin of the second analog switch 13 is similar to that of the first analog switch 12, and is not described herein again, and the main differences are as follows: an output terminal B of the second analog switch 13 is connected to a first terminal of the second light source B (i.e., an anode of the led B), a cathode of the led B is connected to a collector of the second triode NPN2, and an enable terminal ENB of the second analog switch 13 is configured to receive an enable signal LEDB _ EN sent by the control circuit 2 for controlling on/off of the second light source B. In addition, the output terminals of the first analog switch 12 and the second analog switch 13 are each connected to the reference potential terminal GND through the filter capacitor C1.

The digital-to-analog converter 112 adopts a 5V power supply voltage, the power supply pin VDD and the reference voltage pin VREF are both connected to the voltage signal VDD2 output by the first voltage stabilizing circuit 33 in the power supply circuit 3, the first output port OUTA of the digital-to-analog converter 112 is connected to the first non-inverting input terminal INA of the operational amplifier 111, the second output port OUTB of the digital-to-analog converter 112 is connected to the second non-inverting input terminal INB of the operational amplifier 111, the clock signal input terminal SCLK of the digital-to-analog converter 112 is connected to the control circuit 2, the clock signal DAC _ SCLK for receiving the input of the control circuit 2, the input signal input DIN of the digital-to-analog converter 112 is connected to the control circuit 2 for receiving the data input signal DAC _ DIN input by the control circuit 2, the frame synchronization input SYNC of the digital-to-analog converter 112 is connected to the control circuit 2 for receiving the frame synchronization signal DAC _ SYNC input by the control circuit 2, that is, the light source adjusting signal input by the control circuit 2 to the digital-to-analog converter 112 includes: the clock signal DAC _ SCLK, the data input signal DAC _ DIN, and the frame synchronization signal DAC _ SYNC, the data input signal DAC _ DIN may be a control command for controlling the brightness of the light source, and the control circuit 2 inputs the control command to the digital-to-analog converter 112 under the control of the clock signal DAC _ SCLK and the frame synchronization signal DAC _ SYNC, so that the digital-to-analog converter 112 may output the converted analog voltage signals from the first output terminal OUTA and the second output terminal OUTB, respectively. In addition, the ground terminal GND of the digital-to-analog converter 112 is connected to the reference potential terminal GND.

The operational amplifier 111 is powered by 5V, a positive voltage input end V + of the operational amplifier is connected to the voltage signal VDD2 output by the first voltage stabilizing circuit 33, a negative voltage input end V-is connected to the reference potential end GND, a first positive phase input end INA + of the operational amplifier 111 is connected to the first output port OUTA of the digital-to-analog converter 112, a first negative phase input end INA-of the operational amplifier 111 is connected between a first end of the first current limiting resistor RA and an emitter of the first triode NPN1, and a first output end OUTA of the operational amplifier is connected to a base of the first triode NPN 1; a second positive phase input end INB + of the operational amplifier 111 is connected to the second output port OUTB of the digital-to-analog converter 112, a second negative phase input end INB-of the operational amplifier 111 is connected between the first end of the second current-limiting resistor RB and the emitter of the second triode NPN2, and a second output end OUTB of the operational amplifier 111 is connected to the base of the second triode NPN 2. In addition, the first negative input terminal INA-, the first output terminal OUTA, the second negative input terminal INB-and the second output terminal OUTB of the operational amplifier 111 are connected with a protection resistor Rx, which is used for protecting the circuit when the output of the operational amplifier 111 is short-circuited, thereby ensuring the stability of the circuit.

The two-way digital potentiometer 14 is powered by 3.3V, a power supply end VDD of the two-way digital potentiometer is connected to a voltage signal VDD3 output by the second voltage stabilizing circuit 34, a grounding port VSS is connected to a reference potential end GND, the two-way digital potentiometer 14 comprises two potentiometers which respectively form a first adjustable resistor and a second adjustable resistor, a port PA0 and a port PB0 are two ends of the first adjustable resistor, a port PW0 is a tap joint of the first adjustable resistor, a port PA1 and a port PB1 are two ends of the second adjustable resistor, and a port PW1 is a tap joint of the second adjustable resistor, the port PW0 and the port PA0 are respectively connected to two ends of the first current limiting resistor RA, the port PW1 and the port PA1 are respectively connected to two ends of the second current limiting resistor RB, and the port PB0 and the port PB1 are respectively suspended; the first end of the first current limiting resistor RA is connected with an emitter of the first triode NPN1, the second end of the first current limiting resistor RA is connected with a reference potential end GND, the first end of the second current limiting resistor RB is connected with an emitter of the second triode NPN2, and the second end of the second current limiting resistor RB is connected with the reference potential end GND; port RS connects in control circuit 2, a SPI _ RS reset signal for receiving control circuit 2 input, port SHDN connects in control circuit 2, a SPI _ SHDN turn-off signal for receiving control circuit 2 input, port CS connects in control circuit 2, a SPI _ CS chip selection signal for receiving control circuit 2 input, port SCK connects in control circuit 2, a SPI _ CLK clock signal for receiving control circuit 2 input, port SO connects in control circuit 2, a SPI _ MISO daisy chain data for output to control circuit 2, port SI connects in control circuit 2, a SPI _ MOSI serial data signal for receiving control circuit 2 input, resistance adjustment signal that control circuit 2 outputs to double-circuit digital circuit 14 includes SPI _ RS reset signal, SPI _ SHDN turn-off signal, SPI _ CS chip selection signal, serial data signal.

Taking the first light source LEDA as an example, when a voltage signal output by the output terminal OUTA of the operational amplifier 111 passes through the first triode NPN1, the base stage and the emitter stage are conducted, so that the current of the collector electrode is also conducted and flows through the first current-limiting resistor RA, and the voltage signal passing through the first current-limiting resistor RA is input to the first negative-phase input terminal INA of the operational amplifier 111, thereby forming a loop. The constant current control of the current flowing through the second light source LEDB is similar to the first light source LEDA and is not described in detail herein.

The present embodiment enables digital control of the two levels of low light and high light of the first light source LEDA and the second light source LEDB. Taking the first light source LEDA as an example for detailed description, the first light source LEDA is respectively subjected to low-light emission control by using the first current-limiting resistor RA, and the first current-limiting resistor RA is connected in parallel to the first adjustable resistor of the two-way digital circuit device 14, so that the resistors after being connected in parallel can be adjusted by adjusting the resistance value of the first adjustable resistor, the size of the current-limiting resistor in the first light source LEDA is reduced, the driving current flowing through the first light source LEDA is provided, and the high-light emission control of the first light source LEDA is realized; the resistance value adjusting range of the potentiometer corresponding to the first adjustable resistor of the two-way digital circuit device 14 is 100K, the number of taps is 256, the resistance adjusting interval of the first adjustable resistor is 390.625 ohms at the moment, and the high-precision control of the driving current of the first light source LEDA emitting high light can be realized by matching with the 16-bit output analog voltage adjusting precision of the digital-to-analog converter. In addition, the control circuit 2 controls the SHDN pin of the two-way digital circuit device 14 to realize parallel control of the first current limiting resistor RA and the first adjustable resistor and parallel control of the second current limiting resistor RB and the second adjustable resistor, and when the input received by the SHDN pin of the two-way digital circuit device 14 is valid, the first current limiting resistor RA is connected in parallel with the first adjustable resistor and the second current limiting resistor RB is connected in parallel with the second adjustable resistor; conversely, when the input received by the SHDN pin of the two-way digital circuit device 14 is invalid, the first current limiting resistor RA is disconnected from the first adjustable resistor in parallel, only the first current limiting resistor RA is valid, the second current limiting resistor RB is disconnected from the second adjustable resistor in parallel, only the second current limiting resistor RB is valid. Wherein the control circuit 2 can reset the two-way digital circuit device 14 each time power is supplied.

Referring to fig. 8, the control circuit 2 in this embodiment may adopt a low power consumption processor chip, for example, a processor chip of STM32L031K6T6 model, in which an 8MHz crystal oscillator is integrated, which can meet timing requirements during control, and may adopt a 1KB EEPROM integrated therein, which can store data when power is off, so that an external EEPROM chip is not required.

The processor chip is powered by 3.3V, a power supply terminal VDD thereof is connected to the voltage signal VDD3 output by the second voltage stabilizing circuit 34, and the ground port VSS is connected to the reference potential terminal GND, wherein the power supply terminal VDD may also be connected to the reference potential terminal GND through a filter capacitor. Both a BOOT0 pin and a BOOT1 pin of the processor chip are connected to a reference potential end GND through a pull-down resistor Ry, so that a program can be selected from an internal FLASH after the processor chip is powered on; the program download interface of the processor chip includes signal lines SWCLK and SWDIO connected to a 4-pin XH-type socket, and the other two pins of the XH-type socket are connected to the voltage signal VDD3 output from the second voltage stabilizing circuit 34 and the reference potential terminal GND, respectively. The processor chip controls the digital-to-analog converter 112 to have three pins, namely, an FT type pin (withstand voltage can be set to 5V), a pin PB6, a pin PB5, and a pin PB4, which respectively output the clock signal DAC _ SCLK, the data input signal DAC _ DIN, and the frame synchronization signal DAC _ SYNC, and further, the three pins are pulled up to 5V through a pull-up resistor Rs, that is, connected to the voltage signal VDD2 output by the first voltage stabilizing circuit 33, and are configured to be open-drain, so as to serve as a communication interface with the digital-to-analog converter 112 powered by 5V. Wherein the processor chip can simulate the timing by software to control the analog voltage output by the digital-to-analog converter 112.

The processor chip is used for controlling an SPI communication bus part of the two-way digital circuit device 14, a pin PA4 is used for outputting an SPI _ CS chip selection signal to a port CS of the two-way digital circuit device 14, a pin PA5 is used for outputting an SPI _ CLK clock signal to a port SCK of the two-way digital circuit device 14, a pin PA6 is used for receiving SPI _ MISO daisy chain data output by a port SO of the two-way digital circuit device 14, a pin PA7 is used for outputting an SPI _ MOSI serial data signal to a port SI of the two-way digital circuit device 14, a pin PA11 is used for outputting an SPI _ SHDN shutdown signal to a port SHDN of the two-way digital circuit device 14, and a pin PA12 is used for outputting an SPI _ RS reset signal to a port RS of the two-way digital circuit device 14; pin PA15 is for outputting an LEDA _ EN enable signal to an enable terminal ENB of the first analog switch 12 to control power-on or power-off of the first light source LEDA, and pin PA8 is for outputting an LEDB _ EN enable signal to an enable terminal ENB of the second analog switch 13 to control power-on or power-off of the second light source LEDB. In addition, a plurality of unused pins on the processor chip are suspended, and the method comprises the following steps: pin OSC _ IN, pin OSC _ OUT, pin NRST pin PB6, pin PB7, pin PB0, pin P10, and pin PA9.

The low-power-consumption serial interface pin PA2 and the low-power-consumption serial interface pin PA3 of the processor chip can be respectively connected to an XH model socket with 4 pins through a resistor Rz, the other two pins of the XH model socket are respectively connected to a voltage signal VDD3 output by the second voltage stabilizing circuit 34 and a reference potential end GND, the XH model socket is connected to the VDD3 through a fuse S, and the XH model socket can provide 3.3V power supply with no more than 0.5A current for the outside. A pin PA1 of the processor chip is connected with a working indicator lamp LEDC, the working indicator lamp LEDC is connected with a reference potential end through a resistor Ro, the anode of the working indicator lamp LEDC is connected with the pin PA1, the LEDC emits light when 3.3V voltage is output on the pin PA1 of the processor chip, and the LEDC is turned off and does not emit light when 0V voltage is output on the pin PA1 of the processor chip; the processor chip can be arranged after being powered on, the LEDC is lightened for five seconds to serve as a normal work instruction, and the LEDC is turned off and does not emit light after five seconds.

In one example, the control circuit 2 is further connected to the output end of the voltage boosting circuit 32, so that the control circuit 2 controls each light emitting source in the light emitting circuit 1 to stop emitting light when the voltage of the voltage signal output by the voltage boosting circuit 32 is lower than a fourth preset voltage.

Specifically, an analog-to-digital conversion pin PA0 of the processor chip in fig. 8 is connected to an output end of the voltage boost circuit 32 through a voltage-dividing resistor network, taking the resistor network including two resistors Rp as an example in fig. 8, a voltage output by the voltage boost circuit 32 is input to the pin PA0 of the processor chip through a voltage-dividing resistor, the processor chip may detect the voltage output by the voltage boost circuit 32 through the pin PA0, taking the voltage output by the voltage boost circuit 32 as an example, a fourth preset voltage may be set to 5.2V, when the processor chip detects that the voltage output by the voltage boost circuit 32 is reduced to 5.2, it indicates that the power supply voltage of the standard light source is insufficient, the two light-emitting light sources are turned off, and an alarm signal is output through a serial port, so as to avoid that the calibration result of the photometer is affected by insufficient light-emitting intensities of the two light-emitting light sources.

A fourth embodiment of the present invention relates to a calibration method of a photometer, which is applied to a calibration device (e.g., a laptop, a mobile phone, a tablet pc, etc.), referring to fig. 2, when calibrating the photometer 20, the calibration device 30 may be connected to the standard light source 10 in a wired (e.g., a USB connection line) or wireless (e.g., bluetooth, WIFI) connection manner, and the calibration device 30 is connected to the photometer 20 to be calibrated, and the calibration device 30 may calibrate the photometer 20 by using the calibration method of the photometer of this embodiment. The standard light source 10 may be any one of the standard light sources of the first to third embodiments.

The specific flow of the method for calibrating the photometer of the present embodiment is shown in fig. 9.

Step 101, each of two light sources in the standard light sources is independently controlled to emit light rays with corresponding reference intensity toward a photometer to be calibrated, so that a count value of the photometer is a preset reference value.

And 102, performing multiple rounds of calibration tests on the photometer based on the reference intensity corresponding to each light-emitting source to obtain the corresponding relation between the theoretical value and the test value of the pulse rate of the photometer.

And 103, controlling one of the two light-emitting sources to emit light with current test intensity towards the photometer, and controlling the other light-emitting source to emit light with corresponding reference intensity towards the photometer, so as to obtain a current test value of the photometer.

And 104, controlling a light emitting source to emit light towards the photometer, enabling the luminosity counting value to be the current test value, reading the target intensity of the light emitted by the light emitting source, and performing the next round of calibration test on the photometer by taking the target intensity as the current test intensity.

In one example, after step 105, the method further includes:

step 105, establishing a calibration formula of the target test value between the adjacent test values based on the corresponding relation between the theoretical value and the test value, wherein the calibration formula is as follows: y = (a-B) × (B ' -C ')/(B-C) + C '; wherein Y represents a calibrated theoretical value, A represents a target test value to be calibrated, B represents one test value of adjacent test values, C represents the other test value of the adjacent test values, C is more than A and less than B, B 'represents a theoretical value corresponding to the test value B, and C' represents a theoretical value corresponding to the test value C.

Referring to fig. 10, in order to position the standard light source 10 and the photometer 20 at a certain position during the test, the first light source a (LEDA) and the second light source B (LEDB) of the standard light source 10 face the photometer 20, and the light receiving diameter D3 of the photometer 20 is equal to 2 times of the distance D1 between the two light emitting sources, i.e., the perpendicular bisector of the line segment between the first light source a and the second light source B passes through the midpoint of the light receiving diameter D3 of the photometer 20, wherein the light receiving diameter of the photometer 20 may be the diameter of the photocathode of the photometer 20 or the diameter of the lens disposed in front of the photocathode of the photometer 20. In this embodiment, the effective light emission angle of the light-emitting light source (i.e., the first light source a and the second light source B) is represented by θ, and the distance D2= (D1/2) × cot (θ/2) between the standard light source 10 and the photometer 20. For example, if the effective light emission angle θ of the light emission source is 30 degrees and the light receiving diameter D3 of the photometer 20 is 22mm, D1=11mm, D2=20.5mm; the light-receiving diameter D3 of the photometer 20 is 8mm, D1=4mm, and D2=7.5mm. Two light-emitting light sources in the standard light source 10 can adopt through-hole direct-insertion type LED light sources, and are welded to pins of the light-emitting circuit 1 through floating heights, so that the distance D2 is convenient to adjust.

The calibration process of the photometer 20 will be described in detail with reference to fig. 10 and 11.

In the present embodiment, the photometer 20 is basically calibrated in advance to maintain linearity at a pulse rate of 1M/s, and then a reference value is set, which may be any pulse rate within 1M/s, for example, 1M/s, 500K/s, 200K/s, 100K/s, etc., and the present embodiment will be described with reference to the reference value of 1M/s as an example.

The calibration device 30 controls the LEDA emitted light in the standard light source 10 independently and adjusts the intensity of the LEDA emitted light until the count value of the photometer 20 is a preset reference value 1M/s, and the intensity of the LEDA emitted light at this time is the reference intensity A1 of the LEDA; similarly, calibration device 30 controls LEDB emission individually until the count value of photometer 20 is a preset reference value of 1M/s, at which time the intensity of LEDA emission light is the reference intensity B1 of LEDB.

Starting the calibration test, wherein the theoretical value of the photometer in the process of each round of calibration test is as follows: and (N + 1) K, where K is a preset reference value and N is the current number of calibration tests.

In the first round of calibration test, the calibration device 30 controls the LEDA to emit light of the current test intensity (the initial test intensity is the reference intensity A1 of the LEDA) and controls the LEDB to emit light of the intensity B1, when the theoretical value of the pulse rate of the photometer 20 is 2M/s, but due to the non-linearity problem caused by the photon overlapping phenomenon, the test value X2 of the pulse rate of the photometer 20 is < 2M/s, whereby the theoretical value 2M/s of the pulse rate of the photometer corresponds to the test value X2; calibration device 30 then controls the led a to emit light toward the photometer and adjusts the intensity of the light emitted by the led a until the count of the pulse rate of photometer 20 is X2, and reads the luminous intensity A2 of the led a at that time, sets the luminous intensity A2 to the test intensity of the second round of testing, and performs the second round of calibration testing on photometer 20 with luminous intensity A2 as the current test intensity.

In a second round of calibration testing, calibration apparatus 30 controls the LEDA to emit light at a test intensity A2 and the LEDB to emit light at an intensity B1, with the theoretical value of the pulse rate of photometer 20 being 3M/s and the test value of the pulse rate of photometer 20 being X3, whereby the theoretical value of the pulse rate of photometer 3M/s corresponds to the test value X3; calibration device 30 then controls the LEDA to emit light toward the photometer and adjusts the intensity of the LEDA emitted light until the count of the pulse rate of photometer 20 is X3, and reads the luminous intensity A3 of the LEDA at that time, sets the luminous intensity A3 as the test intensity of the third round of test, and performs the third round of calibration test on photometer 20 with luminous intensity A3 as the current test intensity.

The above process is repeated to perform a plurality of rounds of calibration tests, and in the nth round of calibration test, the LEDA is controlled to emit light of the test intensity AN at the calibration device 30, and the LEDB is controlled to emit light of the intensity B1, at which time the theoretical value of the pulse rate of the photometer 20 is (N + 1) M/s, and the test value of the pulse rate of the photometer 20 is X (N + 1), and thus the theoretical value of the pulse rate of the photometer (N + 1) M/s corresponds to the test value of X (N + 1), and then the calibration device 30 controls the LEDA to emit light toward the photometer and adjusts the intensity of the light emitted from the LEDA until the counted value of the pulse rate of the photometer 20 is X (N + 1), and reads the luminous intensity a (N + 1) of the LEDA at this time, sets the luminous intensity a (N + 1) as the test intensity of the third round of test, and performs the (N + 1) th round of calibration test on the photometer 20 with the luminous intensity a (N + 1) as the current test intensity.

Based on this, the corresponding relationship between the theoretical value of the pulse rate of the photometer 20 and the test value in each round of test can be obtained, specifically, see table 1 below, which is a table of the corresponding relationship between the theoretical value of the pulse rate of the photometer 20 and the test value.

Luminous intensity of LEDA	LEDB luminous intensity	True value	Test value
				A1
	0	1M/s	1M/s
				0	B1	1M/s	1M/s
A1	B1	2M/s	X2
				A2
	0	2M/s	X2
				A2	B1	3M/s	X3
A3
		0	3M/s	X3
A3					B1	4M/s	X4
	……	……		……
A19					0	19	X19
	A19	B1	20M/s	X20
……					……	……	……
	AN	B1	(N+1)M/s	X(N+1)
……					……	……	……

Based on the above table, a theoretical value corresponding to each test value of photometer 20 can be obtained, when the test value a of photometer 20 is not in the above table, the test value a is a target test value to be calibrated, two test values adjacent to the test value a are obtained, B represents one of the adjacent test values, C represents the other of the adjacent test values, C < a < B, B ' represents a theoretical value corresponding to the test value B, C ' represents a theoretical value corresponding to the test value C, and then the theoretical value Y = (a-B) × (B ' -C ')/(B-C) + C ' corresponding to the test value a. Therefore, in the use process of the subsequent photometer 20, after reading the count value L of the pulse rate of the photometer 20, the table 1 above can be searched first, and whether the count value L is in the table or not is judged, if the count value L is in the table, the theoretical value corresponding to the count value can be directly read from the table 1; if the counting value L is not in the above table, two adjacent test values of the counting value L are obtained in the above table 1, and the theoretical value Y corresponding to the counting value L is calculated based on the formula Y = (L-B) × (B ' -C ')/(B-C) + C ' described above.

Compared with the prior art, the embodiment provides a method for performing calibration test on a photometer, each of two light emitting sources in a standard light source is independently controlled to emit light rays with corresponding reference intensity towards the photometer to be calibrated, so that the count value of the photometer is a preset reference value, then the photometer is subjected to multiple rounds of calibration test based on the reference intensity corresponding to each light emitting source, in the calibration test process, firstly, one light emitting source in the two light emitting sources is controlled to emit light rays with current test intensity towards the photometer, and the other light emitting source is controlled to emit light rays with corresponding reference intensity towards the photometer, so that the current test value of the photometer is obtained; and then controlling a light emitting source to emit light towards the photometer, so that the luminosity counting value is the current test value, reading the target intensity of the light emitted by the light emitting source, performing the next round of calibration test on the photometer by taking the target intensity as the current test intensity, and repeating the process to complete multiple rounds of calibration tests to obtain the corresponding relation between the theoretical value and the test value of the pulse rate of the photometer. The standard light source comprising two light-emitting light sources can be used for calibrating and testing the photometer to be calibrated, even if the light intensity exceeds a certain pulse rate, the photometer can still be accurately calibrated, and the calibration accuracy is ensured to a certain extent; in addition, the photometers with different electrical characteristics can be calibrated in a targeted manner, so that the photometers with different electrical characteristics can be guaranteed to have better calibration accuracy.

Referring to fig. 2, a calibration system of a photometer according to a fifth embodiment of the present invention includes a standard light source 10 and a calibration device 30 (e.g., a laptop, a mobile phone, a tablet, etc.) according to any one of the first to third embodiments, when calibrating the photometer 20, the calibration device 30 may be connected to the standard light source 10 by a wired (e.g., USB connection) or wireless (bluetooth, WIFI) connection), and the calibration device 30 is connected to the photometer 20 to be calibrated, and the calibration device 30 may calibrate the photometer 20 by using the calibration method of the photometer according to the fourth embodiment.

While the preferred embodiments of the present invention have been described in detail above, it should be understood that aspects of the embodiments can be modified, if necessary, to employ aspects, features and concepts of the various patents, applications and publications to provide yet further embodiments.

These and other changes can be made to the embodiments in light of the above detailed description. In general, in the claims, the terms used should not be construed to be limited to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.

Claims

1. A standard light source, comprising: the light-emitting circuit and the control circuit are connected with each other; the light emitting circuit comprises two light emitting sources;

the control circuit is used for controlling each light-emitting light source in the light-emitting circuit to emit light rays with set light intensity according to the received control signal;

the standard light source is used for calibrating the photometer, and the calibration process of the photometer is as follows:

independently controlling each of two light-emitting light sources in the standard light source to emit light rays with corresponding reference intensity towards a photometer to be calibrated, so that the count value of the photometer is a preset reference value;

performing multiple calibration tests on the photometer based on the reference intensity corresponding to each light-emitting source to obtain the corresponding relation between the theoretical value and the test value of the pulse rate of the photometer; the process of the calibration test comprises:

controlling one of the two light-emitting sources to emit light rays with current test intensity towards the photometer, and controlling the other light-emitting source to emit light rays with corresponding reference intensity towards the photometer, so as to obtain a current test value of the photometer;

controlling the one light-emitting source to emit light towards the photometer, so that the luminosity counting value is the current test value, reading the target intensity of the light emitted by the one light-emitting source, and performing the next round of calibration test on the photometer by taking the target intensity as the current test intensity; the theoretical values of the photometer during each round of calibration test are as follows: (N + 1) × K, K being the preset reference value, N being the current number of rounds of the calibration test.

2. The standard light source of claim 1, further comprising a power supply circuit connected to the light emitting circuit and the control circuit, respectively;

the power supply circuit is used for supplying power to the light-emitting light source in the light-emitting circuit and the control circuit.

3. The standard light source of claim 1 or 2, wherein the light emitting circuit comprises a first light source, a first triode, a first current limiting resistor, a second light source, a second triode, a second current limiting resistor, a first analog switch, a second analog switch, and a signal conversion module;

the first end of the first light source is connected to a power supply through the first analog switch, the second end of the first light source is connected to a collector of the first triode, the first end of the second light source is connected to the power supply through the second analog switch, the second end of the second light source is connected to a collector of the second triode, the input end of the signal conversion module is connected to the control circuit, the first output end of the signal conversion module is connected to the base of the first triode, the second output end of the signal conversion module is connected to the base of the second triode, the emitter of the first triode is connected to a reference potential end through the first current limiting resistor, the emitter of the second triode is connected to the reference potential end through the second current limiting resistor, and the control circuit is connected to the control end of the first analog switch and the control end of the second analog switch respectively;

the control circuit is used for respectively controlling the on and off of the first analog switch and the second analog switch;

the control circuit is used for sending a corresponding light source adjusting signal to the signal conversion module according to the received control signal;

the signal conversion module is used for outputting a first voltage signal to the first light source and outputting a second voltage signal to the second light source according to the received light source adjusting signal.

4. The standard light source of claim 3, wherein the signal conversion module comprises: an operational amplifier and an analog-to-digital converter; the input end of the analog-to-digital converter is connected to the control circuit; a first output end of the analog-to-digital converter is connected to a first positive input end of the operational amplifier, a second output end of the analog-to-digital converter is connected to a second positive input end of the operational amplifier, a first negative input end of the operational amplifier is connected to an emitter of the first triode, a second negative input end of the operational amplifier is connected to an emitter of the second triode, a first output end of the operational amplifier is connected to a base of the first triode, and a second output end of the operational amplifier is connected to a base of the second triode;

the control circuit is used for sending a corresponding light source adjusting signal to the analog-to-digital converter according to the received control signal;

the analog-to-digital converter is used for respectively outputting corresponding analog voltage signals to a first positive input end and a second positive input end of the operational amplifier after receiving the light source adjusting signal;

the operational amplifier is used for outputting a first voltage signal to the first light source according to the analog voltage signal received by the first positive input end;

the operational amplifier is configured to output a second voltage signal to the second light source according to the analog voltage signal received by the second positive input end.

5. The standard light source of claim 3, wherein the lighting circuit further comprises: the double-path digital potentiometer comprises a first adjustable resistor and a second adjustable resistor; the input end of the two-way digital potentiometer is connected to the control circuit, the first adjustable resistor is connected with a first current-limiting resistor in parallel, and the second adjustable resistor is connected with a second current-limiting resistor in parallel;

and the two-way digital potentiometer is used for respectively adjusting the resistance value of the first adjustable resistor and the resistance value of the second adjustable resistor according to the resistance value adjusting signal when receiving the resistance value adjusting signal sent by the control circuit.

6. The standard light source of claim 2, wherein the power supply circuit comprises: the battery pack, the booster circuit, the first voltage stabilizing circuit and the second voltage stabilizing circuit; the battery pack is connected to the input end of the booster circuit, the output end of the booster circuit is respectively connected to the input ends of the first voltage stabilizing circuit and the second voltage stabilizing circuit, the output end of the first voltage stabilizing circuit and the output end of the second voltage stabilizing circuit are respectively connected to the light-emitting circuit and the control circuit, and the control circuit is also connected to the output end of the booster circuit;

the boosting circuit is used for boosting a voltage signal output by the battery pack to a first preset voltage;

the first voltage stabilizing circuit is used for stabilizing the voltage signal of the first preset voltage to a second preset voltage;

the first voltage stabilizing circuit is used for stabilizing the voltage signal of the first preset voltage to a third preset voltage;

the control circuit is used for controlling each light-emitting light source in the light-emitting circuit to stop emitting light when the voltage of the voltage signal output by the booster circuit is lower than a fourth preset voltage.

7. The standard light source of claim 6, wherein the power supply circuit further comprises a power supply female socket and a selection switch; the battery pack is connected to a first input end of the selector switch, the power supply female socket is connected to a second input end of the selector switch, an output end of the selector switch is connected to the booster circuit, and the control circuit is connected to a control end of the selector switch;

the control circuit is further used for controlling the output end of the selection switch to be conducted with the first input end or the second input end of the selection switch.

8. A method of calibrating a photometer, comprising:

independently controlling each of two light-emitting light sources in a standard light source to emit light rays with corresponding reference intensity towards a photometer to be calibrated, so that the count value of the photometer is a preset reference value;

performing multiple rounds of calibration tests on the photometer based on the reference intensity corresponding to each light-emitting source to obtain the corresponding relation between the theoretical value and the test value of the pulse rate of the photometer; the process of the calibration test comprises:

9. The method for calibrating a photometer of claim 8, wherein after performing a plurality of calibration tests on the photometer using the reference intensity as an initial test intensity to obtain a relationship between a theoretical value and a test value of a pulse rate of the photometer, the method further comprises:

establishing a calibration formula of a target test value between adjacent test values based on the corresponding relation between the theoretical value and the test value, wherein the calibration formula is as follows: y = (a-B) (B ' -C ')/(B-C) + C ';

wherein Y represents a calibrated theoretical value, A represents a target test value to be calibrated, B represents one test value of adjacent test values, C represents the other test value of the adjacent test values, C is more than A and less than B, B 'represents a theoretical value corresponding to the test value B, and C' represents a theoretical value corresponding to the test value C.

10. The method of calibrating a photometer of claim 8, wherein the standard light source is directed toward the photometer, and a light receiving diameter of the photometer is equal to 2 times a distance between two of the light emitting light sources; and/or the presence of a gas in the gas,

the distance between the standard light source and the photometer is (D1/2) × cot (theta/2), wherein D1 represents the distance between the two luminous light sources, and theta represents the effective luminous angle of the luminous light sources.

11. A system for calibrating a photometer, comprising: the standard light source and calibration device of any one of claims 1 to 7; the calibration equipment is respectively connected with the standard light source and the photometer to be calibrated;

the calibration apparatus is for performing a calibration method for a photometer of any of claims 8 to 10, the photometer being calibrated with the standard light source.