Seismographic systems - the most widely used method in exploring for oil and gas and detecting earthquakes and tsunamis - utilize a surface shock energy source such as explosives, weight dropping, or gas guns to introduce a wave front into the earth. The effect is similar to creating a small, controlled earthquake.

 The digital seismic equipment that amplifies and records reflected seismic signals on a wideband receiver and tape drive in the field utilizes matched and discrete surface-mount foil resistors. MPR series, NMS4527, NMS2818 and MVR2321-4C  are surface mount foil resistor for seismic equipment application.
 
For these applications, high-precision foil resistors assure virtually noise-free operation. They offer predictable responses and very precise tracking of amplifiers within an individual seismic system or among several interrelated systems- whether operating in the high-humidity heat of the jungle or in the dry cold of the Arctic. When signals are later reconstructed during analysis, the precision-built amplifiers guarantee that the geologist can base their predications on precise, accurate data.

 
A seismic system requires the attenuating resistors to have fast-response precision to prevent missed pulses. They must not be sensitive to temperature changes and must track each other exactly so that the gain settings and ratios are predictable and reproducible over time. The resistors must also exhibit very low current noise to avoid "masking" the reflected signals. Seismic equipment manufactures can find precision metal foil resistors from Microhm Electronics.