Simple device additionally provided with wavelength scanning function for common spectrophotometer

Abstract

The utility model discloses a simple device additionally provided with a wavelength scanning function for a common spectrophotometer, which uses an optical fiber sensor to detect wavelength so as to realize wavelength positioning, and comprises the optical fiber sensor, an optical fiber amplifier, a sampling circuit and an STM32 lower computer, the optical fiber sensor is connected with the optical fiber amplifier, the optical fiber amplifier is connected with the STM32 lower computer, and the sampling circuit is connected with the spectrophotometer and the STM32 lower computer. When the wavelength dial is rotated, scale lines with different wavelengths sequentially pass through light rays emitted by the optical fiber sensor, the optical fiber amplifier can sequentially generate on-off signals, the on-off signals and detection signals, collected by the sampling circuit at the same time, of the spectrophotometer are sent to the STM32 lower computer together to be processed, and finally the wavelength scanning function is achieved. The installation scheme is simple in technology and low in cost, and the function of a common spectrophotometer can be greatly expanded.

Description

Technical Field

[0001] The utility model relates to a simple device for adding a wavelength scanning function to a common spectrophotometer, hereinafter referred to as a wavelength scanning device. Background Art

[0002] Spectrophotometer is a general-purpose detection instrument widely used in many industries. When using a spectrophotometer to detect samples, it is often necessary to draw the absorption spectrum or transmission spectrum of the sample to obtain information such as the maximum absorption wavelength of the sample. Therefore, wavelength scanning is required to obtain the absorbance or transmittance of the sample at different wavelengths. High-end spectrophotometers can directly perform wavelength scanning, but the price is relatively expensive at present; ordinary spectrophotometers such as 721 / 722 have mature technology, stable performance, and low price. They are currently widely used in many domestic industries and have huge stock; but they generally do not have a wavelength scanning function. If you want to draw the absorption spectrum of the sample, you can only manually detect it at each wavelength and finally summarize it to draw a picture. The method is cumbersome, time-consuming and labor-intensive. This device can use the wavelength indication component on the ordinary spectrophotometer to automatically perform wavelength detection and spectrum drawing, thereby realizing the wavelength scanning function. Summary of the invention

[0003] The utility model aims to provide a simple additional device for modifying a common spectrophotometer so as to enable it to have a wavelength scanning function and measure the absorption spectrum or transmission spectrum of a compound.

[0004] To achieve the above purpose, the utility model adopts the following technical scheme: a simple device for adding a wavelength scanning function to an ordinary spectrophotometer, including an optical fiber sensor, an optical fiber amplifier, a sampling circuit, an STM32 slave computer, and a serial port connection line. The optical fiber sensor adopts a reflective optical fiber sensor, and the STM32 slave computer adopts an STM32F103 minimum board.

[0005] In order to make the ordinary spectrophotometer realize the wavelength scanning function, it is necessary to find a way to accurately locate the wavelength during detection and synchronously send out the photoelectric signal detected at the wavelength. Most ordinary spectrophotometers are equipped with a wavelength scale dial, and many dark scale lines are engraved on the light-colored chassis to display the wavelength. Each scale line corresponds to the actual detection wavelength. The user manually rotates the wavelength scale dial and observes the corresponding reading on the dial to know the wavelength during detection. The utility model uses an emission-type optical fiber sensor to detect and identify the wavelength scale line to achieve wavelength positioning. On the wavelength scale dial, because the wavelength scale line is dark in color and weak in light reflection, while the chassis is light in color and strong in light reflection, when the wavelength scale dial rotates, the wavelength scale line passes through the emission light emitted by the optical fiber sensor in turn, and produces strong-weak alternating reflections on the emission light, and the optical fiber amplifier can alternately generate on-off signals; using this switch signal to control the sending of the photoelectric detection signal, the wavelength can be accurately located, and the detection signal of the wavelength can be synchronously sent at a certain wavelength.

[0006] The optical fiber sensor is fixed near the wavelength scale turntable, and its probe is located above the wavelength scale line, and its output end is connected to the optical fiber input end of the optical fiber amplifier; the output end of the optical fiber amplifier is connected to the control signal input port of the STM32 lower computer, and the STM32 lower computer is connected to the computer (host computer) via a serial port connection line. The input end of the sampling circuit is connected to the photoelectric voltage signal output point of the spectrophotometer, and the output end is connected to the sampling signal input port of the STM32 lower computer. The wavelength signal during the detection of the spectrophotometer is detected by the optical fiber sensor, sent to the optical fiber amplifier for amplification and converted into a switch signal, and this switch signal controls the STM32 lower computer to send detection data to the host computer; the photoelectric signal during the detection of the spectrophotometer is sent to the sampling circuit by its photoelectric voltage signal output point, enters the STM32 lower computer for AD conversion, filtering and other processing, and is sent to the computer (host computer) for processing. After the computer (host computer) processes the wavelength signal and the photoelectric signal, a wavelength scanning spectrum can be drawn.

[0007] The utility model can obtain the following beneficial effects: 1. The optical fiber sensor, optical fiber amplifier, STM32 minimum board, etc. used are all existing products in the market, with stable performance, low price and easy to obtain. The installation scheme of the utility model is low-cost, simple and easy to implement, and has a high success rate. A large number of common spectrophotometers currently in existence in China, as long as they have a wavelength scale, can use this patent to simply add a wavelength scanning function, and the original function will not be affected; 2. Make full use of the existing wavelength display components on the original spectrophotometer, use an external optical fiber probe to detect the wavelength scale line to achieve wavelength positioning, and the wavelength positioning is accurate without additional adjustment. 3. The internal circuit modification is simple. Only two lines need to be drawn from the circuit board of the original spectrophotometer, one line is connected to the photoelectric voltage signal output point of the photoelectric sensor or the photoelectric voltage amplifier, and the other line is connected to the ground wire of the front stage, so that the sample detection signal can be digitally processed, which greatly expands the function of the spectrophotometer without affecting the original structure and original function of the spectrophotometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Attached Figure 1 The utility model discloses a schematic block diagram of the principle of a simple device for adding a wavelength scanning function to an ordinary spectrophotometer.

[0009] Attached Figure 2 The utility model discloses a wavelength signal processing schematic diagram of a simple device for adding a wavelength scanning function to a common spectrophotometer.

[0010] Attached Figure 3 The utility model discloses a detection signal processing schematic diagram of a simple device for adding a wavelength scanning function to a common spectrophotometer.

[0011] The description of the accompanying drawings is as follows: 1. spectrophotometer; 2. optical fiber sensor; 3. optical fiber amplifier; 4. sampling circuit; 5. STM32 slave computer; 6. serial port connection line; 7. computer (host computer); 10. wavelength dial of spectrophotometer; 11. photoelectric sensor or photoelectric voltage amplifier of spectrophotometer. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solutions and advantages of the present invention more clear, the implementation methods of the present invention will be further described in detail below with reference to the accompanying drawings and specific examples.

[0013] As attached Figure 1As shown, a schematic diagram of the principle of a simple device for adding a wavelength scanning function to an ordinary spectrophotometer proposed by the utility model is shown, which mainly includes: 2-optical fiber sensor, 3-optical fiber amplifier, 4-sampling circuit, 5-STM32 lower computer, 6-serial port connection line, 7-computer (upper computer), wherein the output end of the optical fiber sensor 2 is connected to the optical fiber amplifier 3, and the probe of the optical fiber sensor 2 is placed above the wavelength dial 10 of the spectrophotometer 1, and the light emitted by the probe is irradiated on the wavelength dial 10 and reflected, and the emitted light is reflected by the probe After receiving, it is sent to the optical fiber amplifier 3, and the optical fiber amplifier 3 immediately generates a switch signal and sends it to the STM32 slave computer 5. The STM32 slave computer 5 sends data to the computer (host computer) 7 under the control of the switch signal; the photoelectric voltage signal of the spectrophotometer 1 is sent to the STM32 slave computer 5 by the sampling circuit 4, and the STM32 slave computer 5 performs AD conversion on the detection signal. Under the control of the switch signal, it is sent to the computer (host computer) 7 by the serial port connection line 6. The computer (host computer) 7 processes the wavelength signal and the detection signal and draws a wavelength scanning spectrum.

[0014] As attached Figure 2 As shown, a wavelength signal processing schematic diagram of a simple device with a wavelength scanning function added to an ordinary spectrophotometer proposed by the utility model is shown. The probe of the optical fiber sensor 2 is placed above the wavelength dial 10 of the spectrophotometer 1. The light emitted by the probe is irradiated on the wavelength dial 10 and reflected. The reflected light is received by the probe and sent to the optical fiber amplifier 3. The probe of the optical fiber sensor 2 is a stainless steel hollow needle, which is equipped with two optical fibers. One of the two optical fibers is used as a transmitter and the other is used as a receiver. The photoelectric detection principle is that the transmitter emits a red laser, and the light reflected by the detection object is received by the receiver and sent to the optical fiber amplifier 3 for amplification, so as to generate a switch current to control the load. When the emitted light is irradiated on the white bottom plate part of the wavelength dial 10, the reflected light is strong, which is equivalent to the light-incoming state; when the emitted light is irradiated on the black scale line of the wavelength dial 10, the reflected light is weakened, which is equivalent to the light-shielding state. By rotating the wavelength scale 10 and letting the wavelength scale line pass through the light beam emitted by the probe in sequence, the optical fiber amplifier 3 can be made to enter the alternating state of "light input-light shielding-light input-light shielding..." in sequence, and generate the switch signal of "on-off-on-off..." in sequence. Therefore, a switch signal can be generated once for each wavelength scale line passed. This switch signal is sent to the STM32 slave computer 5 to control the STM32 slave computer 5 to send a detection signal to the computer (host computer) 7, so as to realize the synchronization of the wavelength signal and the detection signal.

[0015] As attached Figure 3As shown, a detection signal processing schematic diagram of a simple device for adding a wavelength scanning function to an ordinary spectrophotometer proposed by the utility model is shown, which mainly includes: a sampling circuit 4 and an STM32 lower computer 5. Inside the ordinary spectrophotometer, whenever a sample is detected, the photoelectric sensor or photoelectric voltage amplifier 11 on the internal circuit board can generate a corresponding photoelectric voltage signal; the sampling circuit 4 adopts a simple resistor voltage divider circuit, and its input end is connected to the photoelectric sensor or photoelectric voltage amplifier 11 of the spectrophotometer, and the front-stage ground wire of the spectrophotometer is connected to the ground wire of the sampling circuit 4; the photoelectric voltage signal is sent to the sampling input port of the STM32 lower computer 5 as a detection signal after the resistor voltage divider of the sampling circuit 4, and the STM32 lower computer 5 performs AD conversion and filtering on the detection signal. When the switch signal arrives, the processed detection signal data is sent to the computer (host computer) 7.

[0016] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A simple device for adding wavelength scanning function to an ordinary spectrophotometer, comprising an optical fiber sensor (2), an optical fiber amplifier (3), a sampling circuit (4), an STM32 slave computer (5), and a serial port connection line (6), characterized in that: An optical fiber sensor (2) is fixed above a wavelength scale disk (10) of an ordinary spectrophotometer (1); a probe of the optical fiber sensor (2) is located above a wavelength scale line of the wavelength scale disk (10); an output end of the optical fiber sensor (2) is connected to an input end of an optical fiber amplifier (3); an output end of the optical fiber amplifier (3) is connected to an STM32 lower computer (5); a sampling circuit (4) is connected to the spectrophotometer (1) and the STM32 lower computer (5); the STM32 lower computer (5) is connected to a serial port connection line (6); the serial port connection line (6) is connected to a computer (7); the optical fiber sensor (2) is used to detect a detection wavelength of the spectrophotometer to realize wavelength positioning; and the STM32 lower computer (5) is used to process a photoelectric voltage signal of the spectrophotometer.

Images