Abstract: In the analysis of rock ahead of a working face a probe is pushed along a borehole formed in any desired direction in the rock and data produced by the probe is logged for later analysis, or for in-situ analysis. The probe may produce multiple logs. The data logged includes lithological information on the rock and the angular direction of the borehole. The presence of fluids, such as noxious gases, in the borehole can simultaneously be detected.

Abstract: A tire pressure monitor which includes a signal generating section and a signal processing section. The signal generating section has a transducer which produces a first signal which is dependent on the tire pressure, and a transistor the collector current of which is controlled by the first signal. The signal generating section is supplied with power from a battery source and the current so supplied includes the collector current and is therefore dependent on the tire pressure. The signal processing section includes a monitor which monitors the supply current to the signal generating section and a display for providing an indication of the tire pressure.