  The negative ion density and temperature are the two fundamental parameters
that are necessary to quantify the properties of electronegative discharges.
However, determining these parameters by means of electrostatic probes can be
quite challenging because of the inherent inaccuracies involved in determining
the electron/ion saturation currents, electron temperatures and plasma
potential, which relies on charge particle collection by the probe surface; as
well as on the sheath models that are originally developed for an ideal
collision-less plasma. This paper briefly reviews the various limitations
associated with these underlying methods and suggests useful means to correct
the anomaly associated in determining the negative ion parameters based on
electrostatic probes.
