| SC11 Sensor
Interface Product Description The
performance of the Spicer Consulting SC11 Analysis System is now
enhanced using the SC11 Sensor Interface so that it can make all the
measurements required for the next generation TEMs.
Based on a laptop computer and operating under
Windows 95/98/Me/NT/2000/XP, the SC11/SI is purposed-designed for
precision site surveys. It is a portable tool for measurement and
analysis of ambient magnetic fields, vibrations and acoustic levels
in one compact system.
The sensor interface powers and supports a three
axis wideband DC magnetic field sensor, up to 3 accelerometers and a
precision microphone. An auxilliary BNC input allows other sensors
to be used if desired.
The software suite consists of three virtual
instruments, an oscilloscope, a spectrum analyser and a chart
recorder. Results are displayed graphically on the laptop screen.
The data can be printed directly or exported for further processing
in spreadsheet programs.
The SC11 fits neatly into a carrying case which
is supplied. The complete system is accurate, easy to operate with a
minimum of training and produces user friendly results.
SC11 Applications
Surveys
Designed with electron microscope and E-beam vendors and consultants
in mind the SC11 provides all the features needed for site surveys
in one simple, easy to use package.
The SC11 is ideal for making accurate surveys of
magnetic fields, vibrations and acoustic levels. Before installing
equipment such as a scanning electron microscope (SEM) it is
advisable to survey the location first. In an environment where
there are many pieces of equipment, power cables and air handling
units it is difficult to judge in advance whether there could be
problems. You can use the SC11 system to survey the magnetic field,
vibration and sound levels to make sure that they are within
specification at the proposed site for the SEM. With the latest
software, you can load the SEM specifications into the spectrum
analyser for quick comparison with your measurements. The industry
standard 1/3 octave analysis feature is useful in this application.
Trouble shooting and Analysis
The sensors all have the sensitivity and frequency ranges needed to
detect and trace the types of interference that affect electron
microscopes.
The three SC11 programs provide different
troubleshooting clues. A quick look at the waveforms with
oscilloscope can help in finding interference sources by observing
changes of amplitude or phase with position. The chart recorder
gives the best view of slow or intermittent sources. You can use it
to chart floor displacement or slowly varying magnetic fields. You
can chart the RMS value for the full frequency range or just for a
single known frequency. The datalogging feature lets you chart for
an indefinitely long time. You can use the spectrum analyser to
reveal the frequency components of the beam movement of an SEM in
spot mode by connecting its video output to the AUX input.
SC11 Hardware
Laptop computer
The laptop computer is optionally supplied by Spicer Consulting with
all the software pre-installed. Alternatively you may install the
software on your own laptop PC. If desired, Spicer Consulting can
install the system on your own computer. The minimum requirement for
the computer is a 266 MHz Pentium with 64 MB RAM, 100 MB free hard
disc, CD-ROM, 3½in floppy disc drive and PCMCIA slot.
Sensor Interface
The SC11 Sensor Interface has a universal AC power input. It powers
and supports an SC20 3-axis magnetic field sensor, up to 3
accelerometers and a precision microphone. It also has an auxiliary
voltage input with a range of ±10 V. The interface connects to a
National Instruments DAQCard-6024E -a PCMCIA card in the laptop
computer.
Magnetic Field Sensor
The SC20
wideband DC sensor can measure both AC and DC magnetic fields in
three axes. It enables quick surveys of low frequency fields and
3-axis capture of unrepeatable events such as passing trains or
trucks. It is convenient to be able to measure AC fields with the
same sensor. The sensor has a magnetic field measurement range of 40
mG (4 µT) pk-pk with a bandwidth of DC to 5 kHz and is also used in
Spicer Consulting field cancelling systems. Alternatively, if DC
fields are not of real interest, it is possible to use the SC20 AC
sensor in this system. This has the same dynamic range but does not
need to be reset after being moved.
Precision Microphone
The Brüel & Kjær 4190 microphone with 2669L preamplifier connects
directly to the sensor interface. It measures sound levels from 20dB
to 103dB and 1.5 Hz to 2 kHz in this system.
Accelerometer
The accelerometer is a Wilcoxon Research model 731A, with a
bandwidth of 0.1 Hz to 500 Hz in this system. It is suitable for the
measurement of extremely low level vibrations. Each accelerometer
measures vibration along its axis. Up to three can be connected to
measure the three orthogonal X, Y and Z axes at once, or one can be
rotated to measure them one at a time.
Sensor Calibration
The calibration of the magnetic field sensor is NAMAS traceable.
The accelerometer is supplied with a calibration certificate
traceable to the National Institute of Standards and Technology,
Gaithersburg, MD, USA. Spicer Consulting provides a re-calibration
service for the entire system.
CustomisationAll the virtual
instruments can load and save their control settings to named files
so that they can be quickly configured for standard measurements.
User-defined units may be entered for use with other sensors
connected to the auxiliary input. |
