CN206959989U - A kind of visible spectrophotometer based on STM32 - Google Patents

Abstract

The utility model discloses a kind of visible spectrophotometer based on STM32, including optical module, signal acquisition module, microprocessor module, human-computer interaction module, power module；The power module is powered to optical module, microprocessor module, and signal acquisition module, human-computer interaction module are connected to microprocessor module, carries out the transmission of data and signal.Signal acquisition module carries out opto-electronic conversion using silicon photocell, and electric signal by RC low pass filters, is finally delivered to main control chip STM32F103 analog-to-digital conversion passage by the amplification of ICL7650S operational amplifiers.Visible spectrophotometer provided by the utility model employs STM32 processors, and STM32 series processors have performance height, small volume, low in energy consumption, cost is low, supports several operation systems and the features such as development environment；Quantitative, qualitative analysis is carried out to sample in visible spectral range, can real-time display transmittance, absorbance, solution concentration, concentration factor, possess the advantages that high accuracy, good reproducibility and very fast response speed.

Description

A kind of visible spectrophotometer based on STM32

Technical field

A kind of visible spectrophotometer based on STM32 is the utility model is related to, belongs to instrumentation technical field.

Background technology

Spectrophotometer is the instrument for carrying out qualitative and quantitative analysis to material using spectrophotometric hair, because it has spirit Sensitivity is high, selectivity is good, the degree of accuracy is high and using solution concentration scope it is wide the advantages that, be commonly used for medicine, health and epidemic prevention, The fields such as chemurgy.

The spectrophotometer to come out in recent years is mostly using 8 single-chip microcomputers as processor, often there is that disposal ability is relatively low, does not have There is AD conversion in piece, so as to influence the response speed of equipment and the degree of accuracy.

The content of the invention

Purpose：In order to overcome the deficiencies in the prior art, the utility model provides a kind of visible point based on STM32 Light photometer.

Technical scheme：In order to solve the above technical problems, the technical solution adopted in the utility model is：

A kind of visible spectrophotometer based on STM32, by optical module, signal acquisition module, microprocessor module, people Machine interactive module, power module composition；Wherein power module is electrically connected with optical module, microprocessor module respectively, and signal is adopted Collection module, human-computer interaction module are connected with microprocessor module respectively；The signal acquisition module include silicon photocell, ICL7650S operational amplifiers, RC low pass filters connect the photoelectric switching circuit to be formed；The master control of the microprocessor module Chip uses STM32 family chips.

Further, the response wave length of the silicon photocell is 190nm to 1100nm.

Further, the optical module enters slit, condenser, collimating mirror, color provided with illuminator, speculum, monochromator Dissipate original paper grating and exit slit；The monochromator enters slit and is located on the focal plane of condenser and collimating mirror；The outgoing Slit is arranged on the focal plane of collimating mirror.

Further, the illuminator is tungsten halogen lamp.

Further, the human-computer interaction module is made up of four buttons and a LCD display.

Further, four buttons are acknowledgement key, up-regulation key, down key and function key respectively.

Further, the power supply of the power module is Switching Power Supply.

Further, the spectrophotometer possesses two radiator fans, is separately positioned on the both sides of optical module.

Further, the main control chip, tungsten halogen lamp and radiator fan electrically connect with Switching Power Supply respectively, by switch electricity Source powers.

Beneficial effect：A kind of visible spectrophotometer based on STM32 provided by the utility model, its remarkable advantage exist In：

（1）STM32 processors have performance height, small volume, low in energy consumption, cost is low, 16/32 double instruction set, support more The features such as kind operating system and development environment；12 AD conversion built in the STM32F103 series processors that the utility model uses, It can overcome the shortcomings of low side single-chip microcomputer on chip functions.

（2）Photoelectric signal transformation is carried out using the silicon photocell with ultralow dark current so that the utility model has very The high linearity；Photoelectric conversion section uses ICL7650S precision amplifiers, and is positive and negative 5V power works, is changed by I-V Voltage signal it is highly stable, ensure that high measurement accuracy of the present utility model.

（3）Due to the setting of radiator fan, the instrument response time of the present utility model is far smaller than without using actively scattered The spectrophotometer of heat.

Brief description of the drawings

Fig. 1 is structural representation of the present utility model；

Fig. 2 is the light path schematic diagram of the utility model optical module；

Fig. 3 is the opto-electronic conversion schematic diagram of signal acquisition module of the present utility model；

Fig. 4 is chip pin schematic diagram used by the utility model；

Fig. 5 is user interface schematic diagram of the present utility model.

In figure：1. tungsten halogen lamp；2. speculum；3. colour filter；4. enter slit；5. collimating mirror；6. grating；7. go out slit； 8. condenser；9. cuvette；10. silicon photocell；11.LCD display screens；12. function key；13. raise key；14. down key；15. Acknowledgement key.

Embodiment

The utility model is further described below in conjunction with the accompanying drawings.

As shown in figure 1, the visible spectrophotometer based on STM32, by optical module, signal acquisition module, microprocessor mould Block, human-computer interaction module, power module are formed.Wherein power module electrically connects with optical module, microprocessor module respectively, electricity Source module is powered to optical module, microprocessor module；Signal acquisition module, human-computer interaction module respectively with microprocessor module Connection, carry out the transmission of data and signal.

The optical module uses grating CT dispersion systems and monochromatic light speed structure light path, and arrangement is as shown in Figure 2.

The continuous radiation light that tungsten halogen lamp 1 is sent, which is reflected by speculum 2 and monochromator is invested after colour filter 3, enters slit 4, this enters slit 4 and is placed exactly in condenser and monochromator on the focal plane of collimating mirror 5, therefore the complex light for entering monochromator is led to Cross speculum 2 and collimating mirror 5 becomes directional light directive dispersion original paper grating 6, the complex light of incidence is passed through diffraction by grating 6 Formed and be reflected according to certain tactic continuous monochromatic spectrum, this monochromatic spectrum on collimating mirror 5, because instrument outgoing is narrow Seam 7 is arranged on the focal plane of collimating mirror 5, so, after the collimated mirror of spectrum come out from grating dispersion using concentrating light principles into As on exit slit 7, the monochromatic light that exit slit selects specified broadband is fallen by condenser 8 sample is housed in sample chamber The center of cuvette 9, the light that projects is through condenser directive silicon photocell 10 after sample absorbs.

Signal acquisition module mainly has photoelectric switching circuit composition, and circuit diagram is as shown in figure 3, the silicon photocell that design uses The spectral region of application is wide, can be operated between 190nm to 1100nm, while dark current is very small, only 10pA or so.Should Silicon photocell is operated under guided optical mode, that is, connects reverse bias voltage, transmitted light is converted to electric signal, then pass through Signal is amplified by ICL7650S operational amplifiers, then by RC low pass filters, is finally delivered to the 12 of STM32F103 Position analog-to-digital conversion passage.

Microprocessor module is Cortex-M3 as main control chip, its kernel using STM32F103, and advantage is low work( Consumption, low cost, high-performance, such chip are commercially available.The chip model used in the present embodiment for STM32F103RBT6, the chip package form are LQFP (thin quad flat package, i.e., the thin flat envelope in plastic packaging corner Dress), number of pins 64, flash memory capacity is 128K bytes, and Fig. 4 is chip pin schematic diagram.In the both sides of optical module One radiator fan is respectively installed.

Human-computer interaction module is made up of four buttons and LCD display, as shown in Figure 5.LCD display 11 is used for showing inspection Survey result, including transmittance, absorbance, concentration and concentration factor；Four buttons are function key 12, up-regulation key 13 respectively, lowered Key 14 and acknowledgement key 15, wherein function key 12, which are used for switching LCD display, shows transmittance, absorbance, concentration, concentration factor Value, acknowledgement key 15 have confirmation function, and up-regulation key 13 has calibration function and sets the function of concentration factor, and down key 14 has zeroing Function and the function that concentration factor is set.

Power module is using Switching Power Supply, the power supply and tungsten halogen lamp, microprocessor master control borad and two radiatings Fan electrically connects, there is provided electric energy.The tungsten halogen lamp that the utility model uses is 12V 20W specifications, the work(of two radiator fans Rate selects general supply of a 12V 40W Switching Power Supply as system in 5W or so, both can guarantee that the normal work of each module Make, because of Switching Power Supply oepration at full load caloric value will not be caused excessive again, influence the reliability of system.The utility model selects For Switching Power Supply in normal work, power consumption is 60% of rated power or so, and after working long hours, power shell is only There is the sensation of low-grade fever.

Basic functional principle of the present utility model is as follows：

When the material in solution is in the case where the irradiation of light excites, the sink effect to light, absorption tool of the material to light are generated It is selective.A variety of materials all have its respective absorption spectrum, therefore when certain monochromatic light passes through solution, its energy It will be weakened by absorption, the degree and the concentration of material that light energy weakens have certain proportionate relationship, namely meet colorimetric Principle-law of Beer：

A = log1/τ = KCL (1)

Formula（1）In：A is absorbance；τ is transmittance（τ=I_out/I_in, I_outFor transmitted intensity, I_inTo enter transmitted light Intensity）；K is absorption coefficient；L is the optical path length of solution；C is the concentration of solution.

Continuous radiant light is sent by tungsten halogen lamp, is changed into monochromatic light by monochromatic light device, is irradiated on cuvette, part Energy is absorbed by solution, and portion of energy is irradiated on photocell through solution and is converted to faint photoelectric current.The amplification of photoelectric current process, Filtering is sent to STM32 processors and carries out analyzing A/D processing, and result is transported to human-computer interaction module, passes through LCD display Show result.

The transmittance Computing Principle of the something of solution to be measured is as follows：Returned to zero using black matrix, now main control chip is remembered Opto-electronic conversion current value Ia corresponding to black matrix is recorded, then adjusts 100% transmittance using standard sample, now main control chip record ginseng Than the opto-electronic conversion current value Ib of sample；Solution to be measured is finally measured, main control chip can record the opto-electronic conversion electricity of solution to be measured Flow valuve Ic；The transmittance τ c of solution so to be measured just use formula（2）Calculated：

τc = [( Ic– Ia ) / ( Ib- Ia )] *100% (2)

It is of the present utility model as follows using process：

When carrying out detection work using the utility model, power supply is first turned on, preheats some minutes.Then wavelength rotation is rotated The position of button wavelength needed for, opens sample room box, black matrix is put into sample cell, transmittance is switched to by function key, this When transmittance should be 0%, calibrate to 0 by down key；Black matrix is taken away, directly using air as test object of reference, now transmittance It should be 100%, press up-regulation key and calibrate to 100.Now initial work is completed, and cuvette then is put into sample cell, now The transmittance shown on LCD display is sample transmission ratio, can switch display transmittance, absorbance, concentration by function key And concentration factor.The concentration factor of acquiescence is 1000, can be according to being actually adjusted.

In the case of Same Wavelength, by the repeated detection to same solution, the measuring result error of transmittance fluctuates Only 0.2% or so.After start, the numerical value of transmittance is recorded, discovery passes through active heat removal, can as early as possible establish and is Thermal balance inside system, so that measurement data tends towards stability, measurement data of the present utility model is stable only to need 70 seconds Warm-up times.Test result shows that the measurement result of the system is very accurate, and with preferable repeated and faster sound Answer speed.

Described above is only preferred embodiment of the present utility model, it should be pointed out that：For the common skill of the art For art personnel, on the premise of the utility model principle is not departed from, some improvements and modifications can also be made, these improve and Retouching also should be regarded as the scope of protection of the utility model.

Claims (9)

1. A kind of 1. visible spectrophotometer based on STM32, it is characterised in that：The visible spectrophotometer based on STM32 It is made up of optical module, signal acquisition module, microprocessor module, human-computer interaction module, power module, wherein power module point Do not electrically connected with optical module, microprocessor module, signal acquisition module, human-computer interaction module connect with microprocessor module respectively Connect；The signal acquisition module includes silicon photocell, ICL7650S operational amplifiers, RC low pass filters and connects the photoelectricity to be formed Change-over circuit；The main control chip of the microprocessor module uses STM32 family chips.
2. A kind of 2. visible spectrophotometer based on STM32 according to claim 1, it is characterised in that：The silicon photoelectricity The response wave length in pond is 190nm to 1100nm.
3. A kind of 3. visible spectrophotometer based on STM32 according to claim 1, it is characterised in that：The optical mode Block is provided with illuminator, speculum, monochromator and enters slit, condenser, collimating mirror, dispersion original paper grating and exit slit；It is described Monochromator enters slit and is located on the focal plane of condenser and collimating mirror；The exit slit is arranged on the focal plane of collimating mirror.
4. A kind of 4. visible spectrophotometer based on STM32 according to claim 3, it is characterised in that：The illuminator For tungsten halogen lamp.
5. A kind of 5. visible spectrophotometer based on STM32 according to claim 1, it is characterised in that：The man-machine friendship Mutual module includes four buttons and a LCD display.
6. A kind of 6. visible spectrophotometer based on STM32 according to claim 5, it is characterised in that：Described four are pressed Key is acknowledgement key, up-regulation key, down key and function key respectively.
7. A kind of 7. visible spectrophotometer based on STM32 according to claim 1, it is characterised in that：The power supply mould The power supply of block is Switching Power Supply.
8. A kind of 8. visible spectrophotometer based on STM32 according to claim 1, it is characterised in that：The light splitting light Degree meter possesses two radiator fans, is separately positioned on the both sides of optical module.
9. A kind of 9. visible spectrophotometer based on STM32 according to any one of claim 1 to 8, it is characterised in that：Institute State main control chip, tungsten halogen lamp and radiator fan to electrically connect with Switching Power Supply respectively, powered by Switching Power Supply.