Method for the detection of leaks in underground pipelines, especially in water pipelines
DE521573C
Procedure for seismic soil research
DE509630C
Method and circuit arrangement for eliminating interfering alternating currents, the frequency of which deviates from that of the measuring current, in electromagnetic soil exploration by means of quantitative measurement of the electromagnetic field of the soil currents
DE509284C
Method and device for electromagnetic soil research through complete measurement of the electromagnetic elliptically polarized field artificially in the subsurface of excited alternating currents by comparing the amplitudes and phase constants of the field vectors with normal current or voltage values in an alternating current compensator
DE510230C
Procedure for the calibration and control of alternating current compensation devices in electrical soil research work according to the method of the complete measurement of the elliptically polarized electromagnetic field of the soil currents
DE509181C
Method for electrical soil exploration by measuring the elliptically polarized electromagnetic field in the soil
DE504657C
Method for measuring rapid periodic mechanical vibrations
DE498912C
Methods for electrical soil research
DE509629C
Process for finding and limiting masses with deviating electrical or magnetic properties in the subsurface for the purpose of geophysical soil investigation using alternating current by comparing the true, measured electromagnetic field and the normal fields to be expected under otherwise identical conditions over completely homogeneous subsoil
DE471636C
Process for electrical soil exploration through complete measurement of the electrical and magnetic elements of the alternating currents generated by the subsurface, elliptically polarized electromagnetic field
DE529843C
Process for measuring and recording the temporal course of rapid changes in length or torsional vibrations
DE495577C
Procedure for seismic soil research
DE509420C
Method for electromagnetic soil exploration using alternating currents in a transmission loop
DE494831C
Process for electrical soil exploration by means of alternating currents fed inductively into the subsurface and measurement of the elliptically polarized magnetic field using search coils
DE530166C
Horizontal variometer
DE481602C
Procedure for determining the vibration frequencies of mechanical systems (harmonic analysis)
DE469445C
Method for soil exploration by electromagnetic means by exciting alternating electrical currents in the subsoil and recording the elliptical oscillations of the soil current or the magnetic vector
DE495750C
Method for earth exploration using periodic elastic waves
DE468978C
Device for measuring the size and the exact times when very small acceleration vibrations occur
DE438794C
Procedure for the collection of air with a high emanation content
