Abstract: Apparatus and method for monitoring stress in a coating of material. The apparatus has a fluid-filled chamber and a deformable diaphragm on which the coating is applied forming a wall of the chamber, the fluid, which is generally incompressible, having a pressure due to pressing of the diaphragm against the fluid which is indicative of stress in the coating. The apparatus also includes a pressure transducer in communication with the fluid for sensing the fluid pressure and converting the fluid pressure to electrical signals whereby the electrical signals are indicative of the stress in the coating of material.

Abstract: Internal stress on an object being electroplated is monitored continuously with a gauge. The gauge includes a metal receptor which is employed as a second cathode in the electrodeposition process. A separate plating current is supplied between the anode and second cathode, distinct from the separately controllable current between the anode and object being plates or electroformed. The stress on the second cathode is measured with a strain gauge, and a stress deviation from a desired plating stress is determined. The currents between the anode and first and second cathodes are adjusted in accordance with the measured internal stress on the metal receptor to achieve a desired stress condition.The internal stress is advantageously monitored with a foil resistance strain gauge. The strain gauge is connected to a carrier disposed in parallel with the metal receptor. The carrier is rigidly connected at opposite ends to the metal receptor.

Abstract: Internal stress on an object being electroplated is monitored continuously with a gauge. The gauge includes a metal receptor which is employed as a second cathode in the electrodeposition process. A separate plating current is supplied between the anode and second cathode, distinct from the separately controllable current between the anode and object being plated or electroformed. The stress on the second cathode is measured with a strain gauge, and a stress deviation from a desired plating stress is determined. The currents between the anode and first and second cathodes are adjusted in accordance with the measured internal stress on the metal receptor to achieve a desired stress condition.The internal stress is advantageously monitored with a foil resistance strain gauge. The strain gauge is connected to a carrier disposed in parallel with the metal receptor. The carrier is rigidly connected at opposite ends to the metal receptor.