How to Verify a Colorimeter?

Influence of interference filter on verification optical path

Since the wavelength peak of the interference filter changes with the incident angle, it must be ensured that the detection is completed at the angle of normal incidence of parallel light. At the same time, the interference filter must be properly used and maintained, and it must be placed in a ventilated and clean environment to ensure that the appearance of the interference filter is neat and bright, and the coating layer does not wrinkle and peel. When using interference filters for inspection, the inspector should use special tools to ensure that the inspection environment, temperature and humidity meet the requirements of the inspection standard.

Digital colorimeter

Effect of stray light on verification results

The stray light is also important data in colorimeter detection. Most of the factors that generate stray light originate from external noises on optical components, such as foreign objects in light source lamps, lenses, prisms, and reflectors; individual optical components are damaged, or light leaks in the optical path and prisms have cracks. Therefore, the reasons that affect the detection of stray light should be analyzed, and feasible measures should be taken to stabilize the data of stray light from the source.

When the colorimeter is relatively sensitive, it is easy to cause the stray light detection number to be undetermined, thereby increasing the current, and even the phenomenon of zero-position drift, resulting in serious detection errors and ultimately affecting the accuracy of the colorimeter verification results. sex.

Effect of zero drift on test results

The main reasons for the zero-point drift of the colorimeter are as follows:

First, moisture in the photocell cassette of the Caliber 4mm handheld color meter may change the function of components such as photocells or FETs. Secondly, when there is dust on the light source or the surface of the reflector, the airflow and temperature will promote the movement of the dust on the surface of the reflector, which will change the light energy of the photoelectric converter. In addition, poor contact of the rough zero potential will also make the dark current compensation of the colorimeter photocell unstable. Finally, if there is a problem with the shielding of the power transformer, the device will experience high-frequency chatter when changing the sensitivity range. In addition, the aging and quality change of the light source lamp will also cause the instability of the instrument data, and then the phenomenon of zero-point drift will appear.

Color Spectrophotometer

The influence of environment on the detection results

If the verification cycle is more complicated and the dust in the air is relatively large, the filter will be easily contaminated with dust. When the detected ambient temperature is relatively low and the humidity is relatively high, a thin layer of water dew will appear on the surface of the filter. These factors will affect and increase the error of the measurement results. Therefore, before starting work, you must have a detailed understanding of the surrounding environment. The colorimeter must be measured in a suitable environment in order to reduce unnecessary errors and ensure the accuracy of the test results.

In addition, attention should also be paid to some seemingly insignificant details in the verification process. How to fully warm up the colorimeter before the verification, so that the various systems inside the instrument are in a stable state, in order to reduce the verification error and improve the colorimeter verification level, so as to ensure the accuracy and reliability of the verification results.

Leave a Comment

Your email address will not be published. Required fields are marked *