P R E L I M I N A R Y
D
FR091521, R
IRECTION
Section 7-5
Noise Troubleshooting
7-5-1
Purpose of this Section
In this section you will find Noise troubleshooting procedures and hints.
7-5-2
Contents in this Section
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Overview of Types of Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Different Power Outlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Different System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Different Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Disconnect External Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
7-5-3
Introduction
Before you start troubleshooting the noise, you should read the following subsections:
•
EMI Limitations on page 2 - 4
•
EMI Prevention/Abatement on page 2 - 5
•
Overview of Types of Noise
When talking to the customer, try to gather as much information as possible about the conditions when
the noise appear:
Is the noise present...
... all the time?
... after some time of use? (After how long time?)
... at special times of the day (or night)? When?
... at all locations in the hospital, or only in one room/area?
... from time to time, no special pattern of time is observed?
7-5-4
Overview of Types of Noise
There are different types of noise. Use the information next to classify the noise and possible cause.
7-5-4-1
Noise Picked Up from the Air
Electromagnetic Interference (EMI) from radio frequencies, magnetic fields, and transients in the air.
If picked up by a probe cable, the noise will be coherent -"penlight noise" pointing down in the picture -
due to the fact that the noise is received on all channels.
•
Is it a problem on one probe only?
Try another probe.
•
Is it a problem on one of the probe connectors only?
Move the scanner to another location and verify any changes.
7-6
1
EVISION
Section 7-2 - Service Safety Considerations
V
- see below
S60N/V
S70N
B
IVID
IVID
S
M
ASIC
ERVICE
ANUAL