R9533

This is the maximum momentary current that can be handled if its full width at half maximum is less than 10 s.
If the tube is operated near this or higher, the service life is noticeably reduced. Use the tube within the  ecommended current values.

The UV TRON R9533 and R9454 are UV sensors that utilize the photoelectric effect from metal and gas multiplication. These devices are sensitive only to UV light in a spectral range of 185 nm to 260 nm. This makes them easy to use since they do not require optical visible-cut filters. Their electrodes are optimized for ruggedness to resist mechanical shocks up to 10 times (10000 m/s²) greater than the conventional UV TRONs.

The R9533 is a head-on type (UV light enters through the top of the bulb) that easily installs into equipment. The R9454 is a side-on type (UV light enters through the side of the bulb) whose outer appearance resembles the conventional flame sensor R2868. Both these types utilize a plate cathode and feature high sensitivity and a wide field of view (directivity).