PRINCIPLES OF OPERATION

The GMA205 Seismophone was originally developed to cater for the needs of cable fault location technicians where simplicity of use and high accuracy is of utmost importance in noisy environments.

The instrument is equipped with a sharp cutoff noise cancelling filter, which greatly simplifies the acoustic pinpoint location of faults. It is also equipped with a number of other user-friendly features to simplify the procedure.

Display of information is done in analog meter fashion.

The instrument embodies the very latest Analog Electronic techniques. The acoustic amplifier employs high class analog filters to filter as much noise as possible before the signal is amplified. The magnetic amplifier is gain adjustable which allows the operator to attenuate the magnetic signal and then pinpoint exactly where the cable is

Adret
GMA205
GROUND MICROPHONE

Ground Microphone Systems are available in a basic analogue and a high end digital range. In the higher end systems selectable filters and time of flight measurements are standard features.

SPECIFICATION

Filters : 150 – 700Hz
Display : Two 100uA FSD Analogue meters
Acoustic amplifier : Gain: Better than 120 dB
Acoustic indication : Low Impedance Head-phones (4 Ohms)
Dimensions : 200 x 110 x 90mm
Weight : 1.1 kg. (Incl. Batteries)
Power Supply : 2 x Duracell Plus C 9V. Accessible from the side panel.
Battery life : approximately 20 hours

ACCESSORIES

Lid : Aluminium with canvas bag for test cables
Test Cables : 5m HT lead with high current clamps
Earth Lead : 5m yellow/green
Mains Lead : 2m 3 core