Abstract: Sensing methods and a compact, sample holding pin base sensor are provided for detecting if a sample pin is, for example, properly mounted on a goniometer used for automated, high throughput macromolecular crystallography. A first magnet is used for holding a magnetic base; a second magnet is disposed spaced apart from the first magnet. The first magnet and the second magnet have opposite orientation. A Hall-effect switch is located generally centrally between the first magnet and the second magnet. A state of the Hall-effect switch indicates if a sample pin is properly mounted on a mounting member, such as a goniometer.

Abstract: Sensing methods and a compact, sample holding pin base sensor are provided for detecting if a sample pin is, for example, properly mounted on a goniometer used for automated, high throughput macromolecular crystallography. A first magnet is used for holding a magnetic base; a second magnet is disposed spaced apart from the first magnet. The first magnet and the second magnet have opposite orientation. A Hall-effect switch is located generally centrally between the first magnet and the second magnet. A state of the Hall-effect switch indicates if a sample pin is properly mounted on a mounting member, such as a goniometer.

Abstract: A device for automatic balancing of a grinding wheel (2) mounted on a spindle (3) comprises an unbalance correction mechanism made as a housing (5) having chambers (7.sub.1, 7.sub.2, 7.sub.3) connected to a source of fluid (19) through a distributor unit (9) made as hydraulic valves (10) provided with electromagnetic drives (12.sub.1, 12.sub.2, 12.sub.3), pickups (17.sub.1, 17.sub.2, 17.sub.3) of position of the chambers, said pickups being mounted on a machine base (4), an unbalance transducer (1) connected to an amplifier-shaper (13). The output of the amplifier-shaper (13) is connected to a common input of a coincidence gate (16) the other inputs of which and the output are connected respectively to the outputs of the pickups (17.sub.1, 17.sub.2, 17.sub.3) of position of the chambers (7.sub.1, 7.sub.2, 7.sub.3) and to the input of the distributor unit (9), while the unbalance correction mechanism is provided with at least one marker (21).