Materiały konferencyjne SEP 1992

Szkoła Eksploatacji Podziemnej * 92 461 and has 1 ess we i ght. The who 1 e i nt r i ns i cal 1y safe apparat us 1 s easy to be carried Cdimensions 11.5 x 27.0 x 23.0 cm» weight 7.3 kp), and normally only the battery and storage part Cdimen- sions 11.5 X 27.0 X 7 cm, weight 2.8 kp) has to be carried to t he surface and vice versa. The bat tery and storage capac i ty allow 6 - 8 hours of measurements with some 5000 event data and additional data to be stored. The new eąuipment also contains inputs for three technical dri11ing parameters (rotational speed, torąue, axial force), A/D-converters and a special microprocessor-system. Thus arbitra- ry characteristical parameters (e.g. mean-, maximal-vołues, integrals) can be evaluated and stored for each dri11ing-meter. Some results of bas i c i nvestłgat i ons about techni cal dr i i ling parameters related to test drillings are described in the following chapter. 5. Seismoacoustical Investigations During Longwall-Hining For the registration of seismoacoustic events during mining operations several technical demands have to be taken into acco- unt. For example all electric eąuipment used in coal mines under- ground and a surface part (see figurę 9). L^derground up to 16 channels chosen out of 32 geophones are multiplexed and digiti- zed, and then send through several amplifiers sind galvanic sepa- rations to the surface (total distance about 4.6 km). There a Computer (Nova 3D) with the necessary hardware conf igurat ion (printer, plotter, video terminals, tape-recorder etc.) is used to recorder the incoming data streajn on magtapes and to make some on-1 ine evaluations. Additionally al 1 relevaLnt mine data 1 ike the amount of test-dri11-cuttings and others are stored. All stored data can be used for further investigations. The sample rate of the signal registration was 3900 sajnples per second for each channe 1. The reso 1 ut i on and dynami c rangę was 66 dB (12 Bit). Thus the data transfer rate for all 16 chan- nels from underground to the surface was about 820 kBit/s. The overall freąuency response of the system Is linear up to 1000 Hz. All underground parts of the system are fully intrinsically save. The possible geophone probe distribution is limited by