Whiteness meter adjustment and common fault treatment

The adjustment of the Whiteness Meter and the common troubleshooting methods are introduced as follows

2.5 Measuring repeatability is poor (when measuring the same sample, large and small). First, check the ±SV power supply voltage with a digital multimeter to see if the voltage is stable. If it is unstable, check the regulator tubes 78L05 and 79L50, and the capacitor lc. ~C: `Wait to see if it is damaged. If the voltage is normal, use a digital multimeter to check the voltage of pin 2 and pin 3 of the chip 14433 to see if the voltage is stable. If the voltage of pin 2 is unstable, it means that the reference circuit is faulty, and the reference optical circuit and its power amplifier circuit should be checked in detail. ; If the voltage of pin 3 is unstable, it indicates that the measurement circuit is faulty, and the measurement optical circuit and its power amplifier circuit should be checked in detail. If the voltage of pin 2 and pin 3 is not stable, it is likely that the power supply circuit of the bulb is faulty. You can use a digital multimeter to check the voltage at both ends of the bulb to see if the voltage is stable. If it is unstable, check the lamp power supply circuit in detail; if the voltage is stable, it means that the quality of the bulb is not good, and you can try another bulb. 26 During the adjustment process of fluorescent whiteness, when measuring the "4 standard paper sample (or "3 standard plate), the whiteness value is low, and the whiteness value cannot be improved by turning the adjusting screw. The main faults are two aspects. : (1) The measured voltage signal is larger than the reference voltage signal, which causes "overflow" when input to the microprocessor. Use a multimeter to measure the voltage of pin 2 and pin 3 of the chip 14433. The normal voltage of pin 2 should be greater than the voltage of pin 3. If the voltage of pin 2 is less than that of pin 3, adjust the rheostat W,, W: to make the voltage of pin 2 greater than that of pin 3. Voltage. These two voltages are preferably adjusted to the maximum value, but neither can exceed Zv. ()2 The bulb has been used for a long time, and the ultraviolet radiation of the bulb is not enough, so a new bulb should be replaced.