Service electronic devices

A reed sensor is mounted either above or underneath the spray-arm, outside of the washing area, while a magnet is placed on the spray-arm. The reed sensor counts the revolutions of the spray-arm. If for any reason the spray-arm is not working (Dishes inside the dishwasher could block the movement, or the spray-arm is faulty, etc.), the sensor will indicate on a small outside light or display that service is needed. An additional electronic device could also be activated with this reed sensor to stop the machine, so that the dishes or the machine itself will not be damaged. 

Finding a Method Various organizations publish volumes of methods for chemical analysis. One of the most well known is the American Society for Testing and Materials, or ASTM. The ASTM is a not-for-profit organization that provides a forum for producers, users, and consumers, to write standards for materials, products, systems, and services. The ASTM (Figure 5.19) publishes standard test methods encompassing metals, paints, plastics, textiles, petroleum, construction, energy, the environment, consumer products, medical services and devices, computerized systems, electronics, and many other areas. More than 10,000 ASTM standards are published each year in the 72 volumes of the Annual Book of ASTM Standards. Individual standards are also available. 

The Y tube transmits pressure equally to the reference device and the device to be tested. Using the bulb connected to the Y pressure is increased to 300 mmHg and then lowered by 10 mmHg. Recording the pressure on each device validates the accuracy of the aneroid or electronic device, Any device that differs by more than 3 mmHg from the mercury or reference standard is considered to be out of calibration and should be removed from service. 

Development activity Production/service Mechanical/electronic devices Materials and human failures Lightning strikes Human error Quality control Design deficiencies Defective material Warranty claims... 

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