High Temperature Measurement in the Reheat Furnace Furnace Thermometer System A radiation thermometer system, using two sensors, provides a continuous true temperature of the reheat furnace load and with it the possibility of big savings in operation costs. The Measurement The first sensor, a radiation thermometer operating at a wavelength of 3.9μm, measures the apparent temperature of the furnace load. The output from this thermometer contains a component which is due to radiation from the hot background being reflected from the load. A second sensor measures the background temperature. The outputs from the two sensors are applied to a thermometers signal processor which continuously computes the true load temperature corrected for the background radiation. The System The primary channel input to the signal processor is from a Furnace Thermometer System (FTS) which is designed specifically for this measurement. The secondary (background) channel input to the signal processor is obtained either from a second FTS thermometer or from a type R or type S thermocouple, via a transmitter. Copyright © 2001-2012 Land Instruments International The processor corrects for background reflection and load emissivity. It provides a current output, linear with the true load temperature, or a simulated thermocouple type R or S output. A digital display of the true load temperature is provided on the processor front panel. The standard Serial Communications facility gives digital RS232C or RS485 outputs and allows access for system parameters adjustments from a remote computer. The Application High system measurement accuracy (typically better than +20°C/+36°F at 1000°C/1830°F) is obtained in gas-fired (natural/blast furnace/coke oven) steel reheat furnaces - even in the first heating zone. Similarily, high accuracy measurements can be achieved in many furnaces fired on light or heavy oil. Close consultation with Land Infrared is advisable for best results on oil-fired furnaces. The system is also suitable for use on a wide variety of other furnace applications where background reflections are affecting single sensor system measurements. Continuous product development may make it necessary to change these details without notice.

Specifications System Specification Primary Sensor Secondary sensor: Measurement range Primary input: Secondary input a) thermometer: b) thermocouple: Update time: Emissivity range: Outputs: Out of range warning: FTS 500/2000C FTS 900/3600C (permits background compensated (permits background compensated measurements to 2000°C) measurements to 3600°F) Type R or Type S zone themocouples (permits background compensated (permits background compensated measurements to 1500°C) measurements to 2732°F) 500 to 2000°C 500 to 2000°C Type R or S, 0 to 1500°C, via 4-20mA linear transmitter 900 to 3600°F Type...