Abstract: Improvement in free point indicators disclosed in U.S. Pat. No. 3,690,163. Discloses new strain sensing system having all electrical/electronic components, other than coil and diode components, located at earth's surface remote from high temperatures and shock loading. Includes a toroidal armature within the downhole tool having coils or windings to generate a pulsating magnetic flux field developed by an alternating current. A U-shaped permanent magnet is disposed such that a portion of its constant magnetic flux field occupies physical space common with a portion of the pulsating magnetic flux field for mutual influence. A diode provided in series with each winding limits electrical current passing through each winding to pulsating DC. The constant flux of the magnet and the pulsating flux of the coils are relatively positioned in opposing sense whereby the current passing through each winding is of designated magnitude.