Remote measurement of temperature using laser-induced luminescence

A technique is required to measure the temperature of rotating compressor wheels at speeds of up to 80000 rpm and within the range 100°C to 250°C. Present available methods such as emissivity cannot be used due to the substantial interference from surrounding objects, nor can thermocouples due to their effect on the airflow within the compressor. Laser induced fluorescence (LIF) has been used successfully on rotating objects, but at speeds much less than the speeds which are required for implementation on a running compressor. Previous work with LIF has related the decay time of the fluorescence with temperature, this cannot be accurately implemented at high speeds due to the short amount of time that fluorescence is available to the detector, and as such as short amount of the decay curve is collected. The fluorescent peak positions and intensities are to be used for temperature measurement in this project. [Continues.]