Experimental Multi-wavelength Imaging Pyrometer (M-WIP) is presented for remote sensing of temperature profiles of targets with unknown spectrally varying emissivity. A software package was developed for calibration and real-time M-WIP measurements. An experimental 7-filter line-sensing M- WIP system was implemented with a 320 × 122-element PtSi IR-CCD imager and an assembly of narrow-band striped IR filters in the spectral range from 1797 nm through 4512 nm. The M-WIP system was calibrated against a commercial blackbody source over temperature range from 450°C to 950°C. The signal processing included background subtraction, compensation for variation of dark current with detected signal and correction for non-linearities of IR imager response. Initial M-WIP measurements demonstrated real-time temperature resolution ΔT of ±1°C for blackbody target over temperature range from 600°C to 900°C. Temperature resolution of ±4°C was demonstrated for the blackbody source viewed through the double polished silicon wafer with unknown spectral transmissivity in the temperature range from 500°C to 950°C.