Block Diagram; Installation; 1-4.1. Grounding Techniques; Figure 1 Typical Block Diagram - PCB Piezotronics ICP 483C30 Installation And Operating Manual

Signal conditioner

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MODELS 483C30, 483C50, 482M179 AND 483M217 GENERAL OPERATION MANUAL

1-3.

Block Diagram

1-4.

These signal conditioner models comes in a standard 19-inch rack mount enclosure with a 1U (1.75") height. The

enclosure should be located in such a way as to allow convenient access to the power outlet for disconnect purposes.

Since these models have low power consumption, they can be located in confined environments.

Integrating these models into an application that links the outputs to other test equipment powered by line voltages may

lead to errors or loss of signal-to-noise ratio due to ground loops. The evidence of ground loops is easily seen whenever

the fundamental frequency (50 or 60 Hz) or a multiple of the fundamental frequency is present in the system when the

sensors are "at rest." In order to maintain the operating specification of noise and reduce the effects of line interference,

proper grounding techniques should be used. The following procedure may be helpful:

1. Make sure the signal ground lines of all equipment are tied together. The signal grounds of the channels are typically

tied together via the case of the input and output BNC connectors. The individual channels of these models, except for

the 483C30, 482M179 and 483M217 when in isolated mode, have their signal ground line tied together internally at the

power supply.

2. Insure that the sensor does not pick up line noise from the body under test. The case of the sensor should be isolated

from the body under (ground) using an isolation pad. The isolation pad breaks the loop formed by the signal path of the

sensor to the signal conditioner and the return (ground) from the signal conditioner back to the sensor.

3. Make sure that all equipment signal grounds of the test system are tied to the Earth ground at a single point and the

connections linking the equipment ground are made using a wire that can provide a very low impedance connection.

The models 483C30, 482M179 and 483M217 have the additional key feature of input ground isolation. This is

available in ICP® and charge input modes and is available on a per channel basis. For any channel showing potential

ground loop noise, that channel can be changed to an isolated mode, which isolates that channels input ground from all

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