Precautions for visible spectrophotometers

1. The instrument should be placed in a dry room and on a sturdy and stable workbench during use. The indoor lighting should not be too strong. On hot days, do not use an electric fan to blow air directly into the instrument to prevent unstable lighting of the bulb filament.

2. Before using this instrument, users should first understand the structure and working principle of the instrument, as well as the functions of each control knob. Before turning on the power, the safety performance of the instrument should be checked, the power wiring should be firm, and the power should be well connected. The starting position of each adjustment knob should be correct, and then the power switch should be turned on.

Visible spectrophotometer

The 721 visible spectrophotometer has a wavelength range of 360-800nm and a triangular prism dispersion element

1. Check if the starting positions of each adjustment knob on the instrument are correct, turn on the power switch, open the dark box cover of the sample room, keep the meter pointer in the "0" position, preheat for 20 minutes, then select the desired monochromatic light wavelength and corresponding amplification sensitivity level, and adjust the meter to T=0% using the "0" potentiometer.

2. Cover the sample chamber cover to expose the photocell to light, push the handle of the sample holder, and place the reference solution cell (solution is loaded at a height of 4/5 and placed in the first cell) on the light path using a visible spectrophotometer. Adjust the 100% transmittance regulator to make the pointer of the meter T=100%.

3. Repeat the operation of opening the sample chamber cover, adjusting to 0, covering the sample chamber cover, and adjusting the transmittance to 100% until the instrument is stable.

4. Cover the sample chamber cover, push the handle of the sample holder, place the sample solution cell on the optical path, and read the absorbance value. After reading, the sample chamber cover should be opened immediately.

5. After the measurement is completed, take out the colorimetric dish, wash it and invert it on filter paper to dry. Place each knob in its original position, turn the power switch to "off", and unplug the power plug.

The sensitivity of each level of the visible spectrophotometer amplifier is: "l" × 1 times; "2" × 10 times; "3" × 20 times, the sensitivity increases sequentially. Due to the different wavelengths and energies of monochromatic light, different sensitivity levels need to be selected. The selection principle is to use a lower sensitivity range as much as possible when the reference solution can be adjusted to T=100%, in order to improve the stability of the instrument. After changing the sensitivity level, "0" and "100" should be readjusted.