Portable Differential Raman Spectrometer

Testing Instrument
Portable Differential Raman Spectrometer
LATR3020 can reject the fluorescence by shifted excitation Raman difference spectroscopy (SERDS), In the shifted excitation, the Raman signal is very sensitive to the excitation wavelength difference, but the fluorescence signal is not sensitive. The differential technology can be used to suppress the fluorescence. It can directly measure high fluorescent substances, anti-interference, anti-noise, greatly improve the detection sensitivity and signal-to-noise ratio (SNR) of the whole system, filter out interference peaks (such as ambient light peak, fluorescence peak, etc.), retain only pure Raman peaks, and capture tiny signal difference.
DESCRIPTION
Because it can remove all kinds of interferences such as fluorescence, LATR3020 portable Raman spectrometer can not only ensure the accuracy, but also reduce the requirement of light source power, improve the reliability of the whole instrument and the ability of spectrum fault tolerance and error correction. Combined with SERS technology, ppb level detection capability can be achieved, which is suitable for field operation. LATR3020 also has significant reliability, which makes the test results accurate and reliable.

The excellent low stray light condition makes the spectrometer widely used, especially in biochemical analyzer, food safety, pharmaceutical engineering and so on. The multifunctional software promotes the spectral analysis process in application. The remote experiment through Internet access makes the test project easier.




Model
Wavelength Range（cm-1）
Resolution（cm-1）
LATR3020-27
250-2700
6
LATR3020-35
200-3500
8
LATR3020-43
200-4300
10
Test according to ASTM e2529-06;

Application:

Bioscience;

Pharmaceutical Engineering;

Forensic analysis;

Agriculture and food safety;

Gem identification.

Environmental Science
FEATURES
1. Differential Raman spectroscopy technology, effectively suppress fluorescence;

2. Dual-band Laser coupling technology;

3. High sensitivity and TE-Cooled CCD.

4. Ultra low noise circuit;

5. Powerful embedded software.

6. Can eliminate fluorescent background;

7. Search and display peak easy;

8. Android operating system;
9. The 11.6-inch capacitive touch screen supports multi-touch control;

10. USB 2.0；

11. User-Friendly Interface;

12. Battery > 4h;

13. Support LAN remote control;

14. IP67 dustproof and waterproof industry protection.




Differential Raman spectroscopy, also called frequency shift excitation, uses two lasers with slightly different wavelengths to irradiate the sample to obtain two original Raman spectra. The fluorescence background does not move with the slight change of the laser wavelength, but However, the position of the Raman peak will change significantly. The two spectra are subtracted to obtain a differential spectrum. In the differential spectrum, the fluorescence background cancels each other out, and there is no fluorescence interference.
Under ideal circumstances, it is easier to recover the normal Raman spectrum from the difference spectrum by using the accumulation method and the convolution method. However, the actual measured spectrum signal has more or less noise, such as the dark current noise of the photodetector, the thermal noise of the circuit, the ambient background light noise, the stray light inside the spectrometer, and so on. The presence of noise not only affects the signal-to-noise ratio of the measurement, but also reduces the performance of the restoration algorithm. Compared with the laboratory Raman system, the portable Raman spectrometer has worse signal-to-noise ratio and more serious noise interference. In addition to noise interference, in the actual differential spectrum, there may be inconsistencies and asymmetry in the intensities of the positive and negative peaks, which will also reduce the performance of the differential spectrum restoration algorithm. The intensity of the Raman signal is inversely proportional to the fourth power of the wavelength. Although the two excitation wavelengths of the SERDS system are only slightly different, this small difference will still cause the Raman peak asymmetry. The superimposition of noise interference on the spectrum peak can also cause the spectrum peak to be asymmetry. In addition, during the two measurements, the temperature difference after the sample is irradiated and the slight change in the fluorescence characteristics (photobleaching effect) will also cause the spectral peaks to be asymmetry.
SPECIFICATIONS
Model
LATR3020
Interface
USB 2.0 and WIFI
Operating system
Android
Screen
11.6-inch capacitive touch screen, Multi-touch
Battery life
>4 hours
Integration time
4ms - 120s
Power voltage
DC 19V(+/-5%)
Operating Temperature
-10~40 ℃
Operating humidity
< 95%
Dimension(L*W*H)
40×30×18 cm3
Weight
7.8 Kg
Reliability
Spectral stability
σ/μ < 0.5% (COT 8 hours)
Temperature stability
Spectral shift ≤ 1 cm-1 (10-40 ℃)
Variation of intensity(in 5 ~ 40 ℃)
<±5%
Optical Parameters
Spectral range (cm-1)
250-2700
200-3500
200-4300
Resolution (cm-1)
6
8
10
SNR
>3000:1 (918 cm-1 of Acetonitrile,10s accumulation, 200mW)
Entrance slit
50 μm
Focusing
98 mm for incidence and output
Detector
If customized, the resolution performance can be improved.