Abstract: This paper mainly introduces the construction principle of 752 spectrophotometer, and then introduces the use method of 752 spectrophotometer in detail. Finally, it points out the matters needing attention in 752 spectrophotometer.
752 spectrophotometer construction principleThe 752 spectrophotometer consists of a light source chamber, a monochromator, a sample chamber, a photocell cassette, an electronic system, and a digital display. The instrument's internal optical path system. The continuous radiation from the tungsten lamp or the hydrogen lamp is concentrated by the color filter concentrating lens and then sent to the monochromator into the slit. The slit is located directly on the focal plane of the collimating mirror in the condensing mirror and the monochromator, so the monochrome is entered. The composite light of the device is reflected by the plane mirror and the collimating mirror becomes parallel light directed toward the dispersion grating. The grating converts the incident composite light into a continuous monochromatic spectrum uniformly arranged in a certain order by diffraction, at which time the monochromatic spectrum is returned to the collimating mirror and then imaged on the exit slit by the principle of collecting light. The exit slit selects the monochromatic light of the specified bandwidth and falls through the condensing mirror to the center of the sample to be tested in the sample chamber. The light transmitted by the sample is absorbed by the light gate to the cathode surface of the phototube. According to the principle of photoelectric effect, a weak photocurrent is generated.
1) Set the sensitivity knob to “1†(minimum magnification).
2) Turn on the power switch, the tungsten lamp lights up, and it can be measured by preheating for 30 minutes. If you need to use ultraviolet light, turn on the "hydrogen lamp" switch, then press the hydrogen lamp trigger button, the hydrogen lamp will light up, and use it after preheating for 30 minutes.
3) Set the selector switch to “Tâ€.
4) Open the sample chamber cover and adjust the 0% knob so that the number is displayed as “0.000â€.
5) Adjust the wavelength knob to select the desired wavelength.
6) Place the cuvette containing the reference solution and the solution to be tested in the cuvette holder.
7) Cover the sample chamber cover, pass the light path through the reference solution cuvette, and adjust the transmittance knob so that the digital display is 100.0% (T). If the display is less than 100.0% (T), increase the sensitivity of the number of files. Then, the solution to be tested is placed in the optical path, and the digital display value is the transmittance of the solution to be tested.
8) If the light transmittance is not required, after the instrument displays 100.0% (T), adjust the selector switch to “A†and adjust the absorbance knob so that the digital display is “000.0â€. After the solution to be tested is placed on the optical path, the digital display value is the absorbance of the solution.
9) If the selector switch is set to “Câ€, the solution with the known calibration concentration is placed in the optical path, the concentration knob is adjusted to display the digital display value, and the measured solution is placed in the optical path, the corresponding concentration value can be displayed. .
752 spectrophotometer panel
1. Digital display; 2. Absorbance zero adjustment knob; 3. Select switch; 4. Concentration knob; 5. Light source room; 6. Power supply room; 7. Hydrogen lamp power switch; 8. Hydrogen lamp trigger button; Wheel; 10. Wavelength scale window; 11. Sample holder handle; 2. 100% T knob; 13. 0% T knob; 14. Sensitivity knob; 15. Dryer.
752 spectrophotometer precautions1) When the measurement wavelength is above 360 ​​nm, a glass cuvette can be used; when the wavelength is below 360 nm, a quartz cuvette is used. The outside of the cuvette should be blotted with absorbent paper and the surface of the glossy surface should not be touched by hand.
2) The cuvettes supplied with the instrument cannot be exchanged individually with the cuvettes of other instruments. If it needs to be added, it should be corrected before use.
3) When switching the sample chamber cover, be careful to prevent damage to the light door switch.
4) When not measuring, the sample chamber cover should be opened, otherwise the photocell will be fatigued and the digital display will be unstable.
5) When the light wavelength adjustment is large, it takes a few minutes to work. Since the photocell receives light, it needs a response time.
6) Keep the instrument dry and clean.
Nanning Ousibang Information Technology Co., Ltd. , https://www.ousibangvape.com