Hey. I am working on a Metrohm instrument, 797 VA Computrace 1.3, using HMDE as working electrode (Polarography). I am measuring between -1.2 V and +0.2 V. Recently the measured current keeps falling to 0 A at about -0.6 V or I am not measuring any current at all, although my mercury drop hasn't fallen off. Can anyone help me with this problem? I can't figure out what is the problem.