In this work, plasma spectroscopy was used to measure the plasma parameters of a negative spark discharge in a cylindrical electrostatic precipitator (ESP) from spectral data (electron density ne, electron temperature T_e, plasma frequency, and Debye length). The characteristics of the spark-type plasma discharge were characterized using photoemission spectroscopy (PES), and the effect of varying the voltage on the discharge characteristics was investigated using voltages of 15, 20, and 25 kV and a pressure of 252 Torr. The Stark dilation method was used to calculate the electron number density, while Boltzmann diagrams were used to calculate the electron temperature. The results show that increasing the voltage increases the electron number density and plasma frequency but decreases the electron temperature and Debye length. These results indicate that higher voltage promotes more intense ionization, reduces electrostatic shielding, and thus improves the charge-particle dynamics in Electrostatic Precipitator systems. Identifying voltage ranges that yield favorable plasma conditions can improve particle charging and maintain stable discharge.