Abstract: The invention concerns a method of etching an etch material consisting at least partly of metal and an arrangement for implementing that method.According to the invention, the etchant is applied through jet assemblies arranged perpendicularly to each other on the top and the bottom side of the etch material. During the passage of the etch material, the spray pressure at the jet assemblies or the jets may be set to constant values and/or be individually controlled as a function of the quantity of metal to be etched off the top and the bottom side. The invention is particularly suitable for etching circuit boards, whose conductors on the top and the bottom side are arranged perpendicularly to each other.

Abstract: The invention concerns a method of etching an etch material consisting at least partly of metal and an arrangement for implementing that method. According to the invention, the etchant is applied through jet assemblies arranged perpendicularly to each other on the top and the bottom side of the etch material. During the passage of the etch material, the spray pressure at the jet assemblies or the jets may be set to constant values and/or by individually controlled as a function of the quantity of metal to be etched off the top and the bottom side. The invention is particularly suitable for etching circuit boards, whose conductors on the top and the bottom side are arranged perpendicularly to each other.

Abstract: A method for measuring the difference between two voltages with a time-controlled measuring cycle includes feeding two voltages with opposite polarity to one integrator, initially integrating up one of the voltages and subsequently integrating down the other of the voltages with the integrator in an integration cycle, and delivering a voltage corresponding to the mean valve of the difference between the voltage at an output at the conclusion of the integration cycle.

Abstract: A method and apparatus for fixing an instantaneous measured value performs the steps of creating measured values as a mean value of a set number of individual measurements, recording sequential measured values after initialization in a cycle determined by a flow control, checking with a control device if a new measured value exceeds a base value and if the difference between the two latest measured values lies within a given limit range, before fixing the respective new measured value, and checking with the control device if the difference between the individual values resulting from the latest two individual measurements lies within the given limit range and if a fixing of the last measured value and/or individual value takes place when the differences between the mean values and the differences between the individual values lie in the respective given limit range.

Abstract: A guard grille for a window, door, or the like, has a retainer member which is fixedly attached thereto and which is adapted to releasably engage a latching mechanism which is retained on the wall adjacent to a window frame. The latching mechanism includes an inner latching member which is attached to a slidably mounted rod and an outer retainer collet which in the latched position retains the latching member within the retainer member. A spring is placed between the inner latching member and the retainer member, this spring being compressed when the mechanism is in the latched condition. The mechanism is unlatched by means of a knob located adjacent to the inner wall surrounding the window frame, this knob being attached to the rod connected to the inner latching member. Inward actuation of the knob moves the inner latching member away from the retainer collet against the spring, thereby releasing the latching mechanism, the spring and actuation by the operator driving the grille away from the window.