Metal coating thickness gauge

Fig, 12.22 Coulometric gauge for the measurement of metal coating thickness, (a) The Coulotest instrument, together with the measurement probe and typical applications, (b) A section of the probe. (Photograph, courtesy Twin City International Inc.)... 

The range of ultrasonic, eddy-current and magnetic defectoscopes, structuroscopes and thickness gauges for metals and coatings are continuously modernized. 

There are many specific examples of electrochemical devices which do not fit readily into the major areas considered above. An important example is the coulometric thickness gauge (Fig. 12.22) which is used routinely to measure the thickness of metal coatings, particularly in the case of electroplating. A well-defined and precleaned area of the sample is exposed to a chosen electrolyte and under well-agitated conditions (provided by jet flow, or a stirrer) the coating is... 

Wire-wound rod A metal rod wound with a fine wire around its axis to that an ink or coating can be drawn down evenly and at a given thickness across a substrate. The thickness or gauge of the wire controls the depth of wet fihn applied by the rod. Syn equalizer rod, meyer bar, wire-bar applicator. 

Bremond Porosimeter. Apparatus for the evaluation of pore size distribution by the expulsion of water from a saturated testpiece. (P. Bremond, Bull. Soc. Franc. Ceram. (37), 23,1957). Brenner Gauge. An instrument for the non-destructive determination of the thickness of a coating of vitreous enamel it depends on the measurement of the force needed to pull a pin from contact with the enamel surface against a known magnetic force acting behind the base metal. 

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