Fired heater tube skin temperature measurement by contact thermocouple pyrometers, though provide temperature of the tube at that particular spot, will not help to assess the condition nearer the flame or at any location where spots due to overheating are visually observed.

Infrared imaging with a field portable IR camera, with a facility to capture the images in-situ on a floppy disk and subsequent analysis at laboratory on a PC with dedicated software for data analysis and interpretation facilities provides an accurate and effective test for measuring, monitoring and condition assessment.

Presented here are condition monitoring of heater tubes of three heaters in Heavy Crude Unit, High Vacuum Unit and Feed Preparation Unit at BPCL Refinery, illustrating the cases with colour thermographs.