What are the usage and precautions of reflectance meter?

Reflectivity meter use: 1, connect the probe with the electronic control box, while connected to the power supply, boot warm-up 1520 minutes. At this time, the probe should be placed on the black standard plate is good. 2, the school zero: the probe is placed on the black standard plate, adjust the host of the calibration knob, so that the host digital display is 00.0, allowing a change of ± 0.1. 3, the calibration of the standard value: the probe is placed on the white standard plate, adjust the host of the calibration knob, so that the host of the value displayed on the white standard plate and the same value of the calibration, allowing a change of ± 0.1. Repeatedly 2-3 several times, so that the host of the displayed value of the calibration value of the white standard plate, allowing a change of ± 0.1. Repeat 2-3 several times, so that the value displayed by the host to meet the requirements of calibration zero, calibration. (Note: The value of the standard board for two decimal places, calibration, please round up the user to retain a decimal.) 4、Measurement of RB value: move the probe to the black working ceramic plate with a specimen, the value shown on the display is the RB value (or refer to the relevant national standards). 5、Measurement of Rw value: move the probe to the white working ceramic plate with a specimen, the value shown on the display is the Rw value (or refer to the relevant national standards). 6、Calculation to obtain the relative ratio of RB/Rw value. 7、Calculation to obtain the relative ratio of RB/Rw value. 8、Calculation to obtain the relative ratio of RB/Rw value. 9、Calculation to determine the value of RB/Rw value. Reflectance tester notes: 1, to ensure the accuracy of measurement, the instrument should be frequently calibrated, the allowable deviation of ± 0.1. 2, in order to overcome the phenomenon of light fatigue of the photoelectric cell, in the testing of the intermittent time should be placed on the probe above the black standard plate. 3, the preparation of the specimen should be in strict accordance with the relevant national standards.