Using Tips of Spectrophotometer

Today, we will introduce tips about the precautions and troubleshooting of the spectrophotometer. We hope that after reading this article, you can use the spectrophotometer more rationally, protect your spectrophotometer, and prolong the service life of the spectrometer.

Precautions for use of spectrophotometer

At first, let’s pay attention to precautions when using a spectrophotometer.

• The spectrophotometer should be placed in a dry room. Use the spectrophotometer on a sturdy and stable work surface. Indoor lighting should not be too strong. In hot weather, do not use a fan to blow air directly to the instrument to prevent the bulb filament from shining and unstable.
• Before using the spectrophotometer, the user should first understand the structure and working principle of the instrument, as well as the function of each control knob. The safety performance of the instrument should be checked before the power is turned on. The power wiring should be firm and the power should be good. The starting position of each adjustment knob should be correct, and then press the power switch.
• When the spectrophotometer is not connected to the power supply, the meter pointer must be on the "0" scale line. If this is not the case, it can be adjusted with the correction screw on the meter.
• If the test wavelength is greatly changed, wait for a while. After waiting for thermal equilibrium, recalibrate the "0" and "100%" points. Then measure again.
• When the pointer instrument is not powered on, the pointer of the meter must be on the zero scale. If this is not the case, a mechanical zero adjustment is required.
• After using the cuvette, please rinse it with distilled water immediately. And wipe off the water with a clean and soft gauze to prevent the surface finish from being damaged and affect the light transmittance of the cuvette.
• The operator should not move the light bulb and reflector light easily, so as not to affect the light efficiency.
• The photoelectric receiving device of the spectrophotometer is a photomultiplier tube. Its own characteristic is that the magnification is large, so it can be used to detect weak photoelectric signals, but cannot be used to detect strong light. Otherwise, it is easy to produce signal drift and reduce the sensitivity. In view of the above characteristics, care should be taken not to expose the photomultiplier tube to light for a long time during maintenance and use of such instruments. Therefore, during preheating, the cover of the cuvette should be opened or a light-blocking rod should be used to avoid unstable performance due to long-term exposure.
• After the amplifier sensitivity is shifted, it must be reset to zero.
• The matching problem of the cuvette. The cuvettes must be used together, otherwise the test results will be meaningless. Comparisons should be made before each test is performed.

Troubles and solutions

Several typical faults that are prone to occur in the operation of spectrophotometry and their troubleshooting:

• The instrument cannot be zeroed. There are several possible reasons for this failure. Let's list them one by one and propose solutions.
  The light door cannot be fully closed. At this point it is necessary to repair the light door part so that it is fully closed.
  The transmittance "100%" is screwed to the bottom. At this point, the "100%" knob needs to be readjusted.
  The instrument is severely damp. At this point, you can open the photocell cassette, blow it with a hair dryer for a while to dry it, and replace the desiccant.
  Circuit failure. At this point, you can send it to the repair department to overhaul the circuit.
• The instrument cannot be adjusted to "100%". There are two specific reasons for this failure, and we have listed solutions.
  The light energy is not enough. At this time, it is necessary to increase the sensitivity magnification gear, or replace the light source lamp (although the lamp is still on).
  The cuvette holder is not in place. If this is the case, the cuvette holder will need to be adjusted to seat.

The above is a brief introduction to the precautions and troubleshooting of the spectrophotometer. We hope you have learned something after reading this article.