The R9533 high temperature UV tube is extremely reliable for long term operation in harsh environments, even up to military specifications of +125Â°C. Early warning fire and flame detectors are required in many industrial installations. There is range of high sensitivity UV tron sensors for this market. The R2868 miniature UV tron is mass produced for this application where the operating temperature remains below around 60Â°C. In addition to early warning fire, flame and spark detectors the solar blind tube is also used as a flame monitor, combustion sensor, in industrial boilers and similar applications.