A dissociation field effect relaxation method apparatus for measuring rates of very rapid chemical reactions in aqueous and nonaqueous solutions is described. Chemical relaxation times between 0.3 and approximately 5.0 &mgr;sec are measurable on an asymmetric, high voltage Wheatstone bridge, two arms of which are electrolyte cells. The relaxation in weak electrolyte conductance (second Wien or dissociation field effect) caused by a square wave high voltage pulse from a coaxial delay line is detected with an oscilloscope as a changing difference in voltage between opposite points on the bridge. The construction of the bridge and triggering device and the mechanics of balancing the bridge previous to the actual measurement are described in detail.