Description

 

Introduction:
- This product is a third-generation DIY spectrometer, with an ordinary appearance but not simple functions! The observable wavelength range is 340-1050nm (visible light wavelength is 400-780nm, because the Bayer array filter is removed, in addition to visible light, ultraviolet wavelengths of 340-400nm and near-infrared wavelengths of 780-1050nm can also be observed), with a spectral resolution of 1nm, making it easy to distinguish between 1-2nm light sources. The two spectral lines of mercury lamp at 577nm and 579nm can be absolutely separated, sometimes with an accuracy error of 1-2nm.

Specification:
- Host size: 100 x 68 x 50mm
- Measuring wavelength range: 340 - 1050nm
- Shell material: ABS
- Spectrum resolution: 1nm
- Spectrum accuracy (repeatability): 1 - 2nm
- Interface: USB2.0
- Interface protocol: UVC (USB Video Class)
- Pairing software: Theremino Spectrometer
- Computer system: for Windows
- Spectral element: diffraction grating
- Grating parameter: 1350 lines
- Photosensitive element: OV2710 (2MP)
- Photosensitive type: focal plane array CMOS (1/2.7”)
- Lens material: glass coating
- Calibration fluorescent lamps: equipped
- Spiral lamp holder: equipped

Improvements:
- The third generation product has undergone significant changes in the core component camera. A batch of camera sensors without cover slips were customized, and with the assistance of some chemical reagents, the original color filter (Bayer array) was peeled off. The camera changed from color to black and white while obtaining higher sensitivity and sharpness. Under exposure parameters of -8 or -7, the main peak at 611nm can reach 80% to 90% peak. If there is no good sharpness, even if the sensitivity is good, the peak will be passivated. In addition, after removing the filter, the sensitivity wavelength range of the camera is also expanded, because before the filter is removed, infrared and ultraviolet also need to pass through the filter to be perceived by the photodiode pixels. Except for the Bayer array, light from various wavelengths can directly reach the photodiode. The main control chip program of the third generation camera is the same as that of the first generation, both using "USB-ZH", and the camera sensor chip model is also OV2710, but the process is different.

Introduction to Optical Path: Light Enters in Sequence
1. Incident slit; 2. Line grating; 3. Lens; 4. CMOS array (OV2710)
- Comparison of optical paths: It can be seen that compared to commercial spectrometers, DIY optical paths are very simple. Omitting the fiber optic entrance interface/collimator/reflector, using a transmissive grating instead of a reflective grating. Using a CMOS array (OV2710 camera) instead of a CCD linear array reduces costs significantly, makes debugging easier, and has better repeatability. (Slight errors in the incident angle do not affect the results), high resolution, easily achieving a resolution of 1nm. The only drawback is the low utilization rate of light energy, which makes it impossible to detect weak light.

Key Process Introduction: Bayer Matrix Stripping Technology
- The removal process of the camera Bayer array is crucial, as it not only improves the sensitivity and sharpness, but also has the ability to detect infrared and ultraviolet light.

Other Details Introduction: Selection of Diffraction Grating
- Use a 1350 line DVD grating instead of a 625 line CD grating. The 1350 line grating has a larger deflection angle, allowing for more complete dispersion of light of different wavelengths, which is also one of the reasons why it is easy to achieve a resolution of 1nm. Note that the principle of the upper left structure is that the deflection angle is not large, and it is a CD grating (625 lines/mm)

Other Details Introduction: Narrow Slit Process
- Adopting a 0.26mm stainless steel slit, the dimensional accuracy is very good, controlled within +/0.01mm. Excessive slit affects resolution accuracy, while insufficient slit affects brightness. Users can replace or customize the slit according to their needs. Note: Changing the slit by yourself may void the warranty.

Other Details Introduction: Lens Focusing Process
- We have developed a specialized program to assist in focusing assembly. This program can collect camera images in real time, adopting for OpenCV to detect whether the image is out of focus or blurry, and continuously calculate evaluation values (standard deviation calculated by Laplacian operator) when the lens is in different positions to find the clearest optical lens position, avoiding the inability of employees to make intuitive judgments and achieve the same accuracy for every camera.

Applications:
- Measure the spectrum of LED lights to determine whether the LED is a full spectrum lamp or an eye protection desk lamp, helping users to have a detailed understanding of the desk lamp they have purchased.
- Detect computer monitors, mobile phone monitors, blue light wavelength intensity, and whether they are eye friendly.
- Measure the photon beauty device, nourishing light device, various plant growth lamps, spectral wavelength distribution, and whether they are consistent with the promotion.
- Measure laser wavelength and distinguish small differences in wavelength.
- Conduct optical experiments and teaching demonstrations to explain knowledge of light source spectra.
- Conduct experiments relying on spectrometers, such as flame reaction, absorbance detection, and fluorescence detection.
- Measure the passband of various filters used on the camera (halogen lamps are recommended as light sources, xenon lamps can also be used), and also measure the passband of laser protective goggles.
- Spectrometer combination: full spectrum lamp + colorimetric dish + filter, to achieve absorption detection, such as chlorophyll absorption experiment, only halogen lamp is recommended here.
- Spectrometer cooperation: various excitation light sources (such as lasers, ultraviolet lamps) are used to achieve fluorescence detection, determine substance elements or materials or concentrations, such as alcohol concentration testing.
- Reverse engineering the light source of certain detection equipment to determine the type of light source through characteristic spectra.

Package Included:
- 1 x Spectrometer
- 1 x Calibration Light Source