2008 JINST 3 P11004 PUBLISHED BY IOP PUBLISHING AND SISSA RECEIVED: September 16, 2008 ACCEPTED: October 26, 2008 PUBLISHED: November 14, 2008 The calibration of a Meson Spectrometer with a Least Squares Minimization technique M.H. Shah Bukhari ab a Medium-Energy Physics Group, Department of Physics, University of Houston, Houston, Texas 77204, U.S.A. b Department of Physics, Faculty of Marine Sciences, Lasbela University, Uthal, Lasbela 90150, Balochistan, Pakistan * E-mail: mhshah786@gmail.com ABSTRACT: The task of calibration and analysis of the Neutral Meson Spectrometer (NMS) was undertaken with the help of negative kaon (κ - ) data from the Brookhaven laboratory E931 ex- periment. A useful least squares minimization technique, using Chi-Squared Minimization, was developed and implemented to determine the coefficients for 120 Cesium-Iodide crystals in NMS. This short paper reports the details of this technique which finds application in a number of areas, especially electromagnetic and meson spectrometry/calorimetry, where a least squares estimation method is required for calibration of multi-channel instruments. KEYWORDS: Spectrometers; Analysis and statistical methods; Photon detectors for UV, visible and IR photons (solid-state); Detector alignment and calibration methods (lasers, sources, particle-beams). * Present Address c  2008 IOP Publishing Ltd and SISSA http://www.iop.org/EJ/jinst/