Geophysical Instrumentation at CSIR-National Geophysical Research Institute.

At times when there was hardly any commercial equipment available for important field investigations and no other Institute in India was engaged in the development activity of Geophysical instruments, CSIR-NGRI has taken an important and challenging initiative of design and development of Geophysical instruments in early 1960's. A wide variety of geophysical instruments was designed and manufactured for field use and successfully demonstrated their usage in different field investigations across different parts of the country. After the successful demonstration of these instruments, they were produced on batch scale at the Institute, to meet the immediate requirements of research, teaching and survey organizations and subsequently the know-how for few instruments were transferred to commercial firms. This paper is a review of few of the important development activities of Geophysical instruments carried at CSIR- National Geophysical Research Institute (CSIR-NGRI) such as Resistivity meter, Seismic refraction timer, Proton Precession Magnetometer (PPM), Time domain Electro Magnetic System (GS-100), Flux Gate Magnetometer, Magnetic susceptibility meter, Metal detector, Pulsed Transient Airborne E.M System, Rubidium Vapour Magnetometer, Magneto telluric sounding System, EM Enslin unit, Salinity meter, Automatic water level and quality meter, Borehole logger etc. Another important work is the development of technique and a device for measurement of spectral induced polarization response using Pseudo Random Binary Sequence (PRBS) current source, Multi electrode SP Measurement System. [ABSTRACT FROM AUTHOR]