i3070series6_Site_Preparation+11-12.3.pdf.pdf - 第23页
Keysight i3070 Series 6 In -Circuit Test System Site Preparation RF Attenuation Requirements Intr oduction 4-2 Calculating Sit e Attenuation 4-4
3-6 Site Preparation
3 Structural Requirements
Storage Space Requirements
Setting up your system requires planning for storage. Obviously, you will need a
handling and staging area for the boards you will be testing. Not so obviously, there
are other things that you will need to store, such as the test fixtures.
Backup media storage
The i3070 system is reliable, but no system is safe against data loss due to system
disk or computer failure. Run system backups at regular intervals. Before the
system is installed, plan for backup media storage in the system area. To be safer
still, always place a recent backup in a different area or building.
Fixture storage
You will have a significant investment in your system fixtures. They are precision
machines and must be kept clean and undamaged. Plan safe and dust-free storage
near the testhead for your fixtures.
You will receive a Pin Verification Fixture with the first testhead at your site to use
to test the MINT pins of your systems. Be sure to keep the Pin Verification Fixture in
your fixture storage area.
Note the following with respect to fixture storage:
• Don’t store fixtures on painted shelves. The bottom of the fixture will scrape
small particles of paint off the shelf which will fall into and contaminate the
testhead’s interface pins.
• If possible, cover your fixtures when not in use, especially when the air contains
a high level of particulates.
• Don’t store fixtures on paper-, cardboard-, or carpet-covered surfaces. These
materials could contain corrosive substances that would react with the fixture’s
gold-plated personality pins.
• Don’t store fixtures on wooden shelves. Wood splinters can be carried on the
bottom of the fixture to the testhead, thereby contaminating testhead interface
pins.
• Don’t stack fixtures on top of one another.
4-2 Site Preparation
4 RF Attenuation Requirements
Introduction
This chapter describes the installation requirements and possible solutions where
additional RF attenuation measures are required as part of the installation. The
limits for the radiated RF emissions are set by various standards such as CISPR 11,
an international standard, ICES-001 for Canada, EN 61326 for the EU and the Radio
communications (Electromagnetic Compatibility) Standard 2001 for Australia.
The Target Site Attenuation, meaning the required attenuation to be provided by
the site for the installation, is 15 dB for i3070 test systems. Some sites are
permitted radiated RF emissions higher than allowed for individual products. For
example, in the EU a local PTT agency may provide for a Site Allowance. If a Site
Allowance is permitted, subtract the Site Allowance from the Target Site
Attenuation and this becomes the Required Site Attenuation.
The Available Site Attenuation of a specific installation can be calculated as shown
in Calculating Site Attenuation. Consider the location of existing walls as well as
installing additional walls when considering the possible locations for the
installation. After choosing the installation location and determining any additional
needed site preparations, compute the Available Site Attenuation for this
installation.
In the event that the Available Site Attenuation for this installation is not greater
than or equal to the Required Site Attenuation, consider the use of a Shielded Cabin
with specified shielding performance. Other shielding methods such as conductive
wallpaper, metallized walls, etc. may be used. These methods may require an
approval test. This test, called in situ testing, may need to be performed by an
authorized agency or an organization designated by an authorized agency.
Table 4-1 shows the results of using calculating the required site attenuation with
no site allowance.
D = 30log
-1
((R - 10 * n) / 20);
where R = (10 * n), else D = 30 m
When the i3070 system is testing a device under test (DUT)
the RF emission levels may increase because the DUT will
also be radiating RF energy.
The Available Site Attenuation for this installation must be
greater than or equal to the Required Site Attenuation.