Adam Equipment CBC 16, Руководство по обслуживанию

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© Adam Equipment Company 2007
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5.0 CBC DESCRIPTION
The CBC scales have an enclosure with all components mounted within it. To gain access
to the components remove the 5 screws securing the cover to the base.
The basic unit consists of:
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Base
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Load Cell frame
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Power switch
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Main PCB assembly
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Battery
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Display PCB assembly
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Keypad
All models of CBC are similar except the selection of load cells and the program.
Normally if a problem is found with a circuit board the most cost effective method of
solving the problem is to replace the circuit board.
The main PCB assembly includes:
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A/D converter (AU1),
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Microprocessor (DU1) and
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Power supply/battery charger circuits (DU5, T2).
6.0 LOAD CELL DAMAGE
The most common reason a scale fails is that the load cell has been damaged. The
damage can be from 2 primary causes. The first is physical damage due to an overload or
an impact from the side and the second is damage due to the environment, such as
moisture, extreme heat or a cut cable if the cables are exposed.
PRINCIPLE OF OPERATION
The stain gauge load cell is a method of measuring the amount of stress put onto a metal
structure due to a weight being supported by the structure. The stress is measured using
4 strain gage sensors mounted in a particular way on the metal structure.
These 4 strain gauges are connected in such a way that they form a wheatstone bridge.
See figure below. In the simplest load cells there are only the 4 resistances of the strain