Elekta Neuromag NM21283A, Руководство пользователя

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NM21283A-A 1
Introduction
This manual has two functions. It is at the same time the user’s manual of
the sensor tuning program and also a manual describing the operation
principles of Vectorview™ sensor hardware. Detailed descriptions about
the SQUID sensor system, electronics, and tuning principles, are given in
addition to the description of the tuning program.
The SQUID tuner program tune_vv, is a versatile tool that can be used in
maintenance of Vectorview™ measurement system. It facilitates the tun-
ing and monitoring of the performance of the sensor electronics.
The key features provided by the program are:
• Measuring white noise level.
• Automatic fine tuning of the noise level.
• Adjusting sensor operating point manually.
• Measuring several characteristic curves of the sensors.
• Manual heating of single or all sensors.
The functionality of the program depends on the expert level being used.
The lowest level 0 allows noise measurements and automatic fine tuning
of the system. The expert level 1 allows more complicated measurements
and setting of various parameters affecting the program. Using the fea-
tures in level 1 requires understanding of the operation of the sensor sys-
tem, and is intended to be used by service personnel.
This manual is divided in three parts. The first one describes how to tune
the system automatically using the SQUID tuning program. This is a
everyday operation, and reading of this part is recommended for all users.
All expert level 0 operations are explained.
The second part explains the operating principles of a SQUID sensor and
electronics. It also contains a detailed description how the sensors are
tuned manually. This information is essential for the maintenance person-
nel and for understanding advanced features of the tuning program.
The third part describes advanced features of the tuning program. These
are available when the expert level is set to 1, and are normally used only
by the maintenance personnel.