SC11 Sensor Interface Analysis System

The SC11/SI is the latest version of our comprehensive site survey equipment. It features data acquisition and pre-processing by an embedded microcomputer in the Sensor Interface for enhanced performance. The separate data acquisition card (DaqCard) used by our earlier systems is not required. The data interface to the computer is through an industry standard USB connection, which enables the system to be used with most modern laptops running Microsoft Windows.

Manufacturer

Spicer Consulting

Spicer Consulting has built a world-wide reputation in magnetic field cancelling for electron microscopes and similar instruments. Today, working with equipment manufacturers and users alike, the company is recognised as an industry expert in maximising the performance of electron microscopes, electron beam lithography systems, CD-SEM and focused ion beam tools. Spicer Consulting magnetic field cancelling systems protect sensitive equipment in the world's leading laboratories, universities and semiconductor manufacturing plants, as well as in the test facilities of electron and ion beam equipment manufacturers. Its magnetic field, vibration and acoustic analysis systems have been adopted as standard equipment for the conduct of site surveys by leading equipment manufacturers.

Key Features

  • Windows laptop based measurement and analysis system
  • Universal AC power input (100 - 240 V~)
  • Interface with USB connection to laptop, supports multiple sensor types
  • Data acquired and pre-processed in Interface
  • Inputs for 2 x 3-axis magnetic field sensors, 3 x Wilcoxon 731A accelerometers, Brüel & Kjær precision microphone, analog signals via BNC
  • Measures environmental magnetic fields, vibrations and infrasound levels
  • Narrow-band and third octave spectrum analysis
  • Chart recorder with data logging for long term measurements
  • 20 kHz Bandwidth in Scope and Spectrum programs
  • Measures 9kHz magnetic fields from wafer transport robots
  • Measures DC fields from trams, trains and elevators

Overview

The SC11/SI is the latest version of our comprehensive site survey equipment. It features data acquisition and pre- processing by an embedded microcomputer in the Sensor Interface for enhanced performance. The separate data acquisition card (DaqCard) used by our earlier systems is not required. The data interface to the computer is through an industry standard USB connection, which enables the system to be used with most modern laptops running Microsoft Windows. The system is designed to be flexible and adaptable to suit customer requirements. The core system includes the Sensor Interface, Software and a custom carrying case. And a typical system also includes a DC-13 kHz three axis magnetic field sensor, an accelerometer and a precision microphone. The software suite includes three virtual instruments, an oscilloscope, a spectrum analyser and a chart recorder that display results graphically on the laptop screen. Also included are “SCplot”, a comprehensive results plotting program, “SC11 Wizard”, which aids in setting up a single measurement, and “SC11 Survey”, which automates a complete survey.

Sensor Interface

The Sensor Interface operates from universal AC power (100-240 V ~ 50/60 Hz) which is used to power all the sensors and its embedded Analog Devices Blackfin microcomputer. For long term monitoring applications, where loss of data would not be acceptable, the sensor interface can be powered from an un-interruptible power supply. Our tests with a fully charged 350W UPS from APT provided up to four hours of operation. There are inputs for two Spicer Consulting 3-axis magnetic field sensors. Sensor SC24/DC+AC and Sensor SC11/AC are compatible. If two sensors are used we recommend they are the same type to avoid confusion. There are inputs for three Wilcoxon 731A accelerometers. The inputs provide the constant current load and power supply for each Wilcoxon 731A and are suitable for most other types of piezo accelerometers when using the spectrum program. There is an input for a Brüel & Kjær 4190/2669L precision microphone. The Interface provides the special power supplies for the 2669L microphone pre-amplifier to enable the microphone to operate to its full specification. There is a general purpose DC coupled auxiliary input via a BNC connector at the back of the interface.

A multi-channel 13 bit ADC controlled by an embedded Analog Devices Blackfin Microcomputer acquires all the signals in digital format inside the Interface. The microcomputer performs extensive signal pre-processing before the signals are sent to the laptop computer through the USB connection.

Sensor SC24/DC+AC

This is the 3-axis magnetic field sensor most commonly used with the SC11/SI/USB system. It can measure DC and AC fields, e.g. changing DC fields from trams and elevators and AC power line fields. It has internal bias coils that are used to null the Earth’s field. The bias coil currents are reset by clicking an icon on the program screen, each time the sensor is moved. The measurement range is ± 20 mG. The sensor has low noise and when fully warmed up the DC drift is below 20μG/day. It is not recommended for measuring higher frequency fields (e.g. 9kHz from wafer transport robots). Sensor SC11/AC should be used for this purpose. (The MEDA uMAG-01N one-axis DC magnetometer is also supported).

Sensor SC11/AC

This is a 3-axis AC magnetic field sensor with a lower bandwidth of 1 Hz and a dynamic range of 80 mG (8 mT) Pk-Pk.

Wilcoxon Research model 731A accelerometer

The Wilcoxon Research model 731A has a measurement range of 200 mg's Pk-Pk and a bandwidth of 0.1 Hz to 500 Hz when used with SC11/SI/USB system. It is suitable for the measurement of extremely low level vibrations. Its noise limit is 0.03μg/√Hz at 2Hz. The system supports simultaneous measurements by three accelerometers. Each accelerometer measures along one independent axis. With three correctly oriented accelerometers, vibration can be measured in three orthogonal axes.

Brüel & Kjær 4190 microphone

The Brüel & Kjær 4190 microphone with 2669L preamplifier connects directly to the sensor interface. It provides acoustic measurements to acoustic laboratory reference standards. It measures sound levels from 20dB to 110dB and 1.5Hz to 20kHz. It measures infrasound levels (i.e. frequencies below 20Hz) which can limit the performance of transmission electron microscopes by vibrating the sample. (The Sound Level Meter supplied with the SC11/Compact is also supported).

Product range

SC11 Compact Analysis System
SC11 Sensor Interface Analysis System
SC11 Auto Survey System
SC28 Monitoring System

Software

Calibration

The magnetic field sensors are manufactured and calibrated by Spicer Consulting. Their calibration is NAMAS traceable. The Wilcoxon accelerometers are supplied by Wilcoxon Research Inc. Germantown MD, USA with a calibration certificate traceable to the National Institute of Standards and Technology, Gaithersburg, MD, USA. The Brüel & Kjær 4190 microphone is supplied with a calibration certificate traceable to the National Institute of Standards and Technology, Gaithersburg, MD, USA. We provide a re-calibration service for the entire system.

Oscilloscope

The oscilloscope program is useful for initial investigation of magnetic fields during trouble shooting of electron microscope imaging problems. The oscilloscope has a bandwidth of 20kHz on its shorter time ranges. The A input is DC coupled. There are common controls for the time base and the vertical axis ranges. There are independent controls for the auxiliary channel ranges and the vertical position of each channel. The RMS and Pk-Pk values of the waveforms are measured and displayed numerically. Icons on the top toolbar are used to control operation. These include “pause”, “one-shot”, “reset DC sensors” and “zero position”. The “lock position” icon activates AC coupling that varies with the time base. The effect is to stabilise the vertical position of the traces, which is useful with an AC sensor that is being moved frequently during searches for magnetic field sources. Files to set-up the controls may be imported and exported for future use. Results may be saved as an image using the windows alt-print-screen function or exported as a text file or Matlab level 5 file for processing by the SCplot program.

Analyser

Tracking cursors are provided to measure features of the spectrum as well as define bands for RMS measurement. Harmonic cursors can be used to recognise harmonics in the spectrum and enable more accurate measurement of the fundamental frequency. Successive spectra can be combined over a period of time, as an average to reduce noise, or to find the worst case peak values. Spectra can be data-logged to a file at a maximum rate of once every minute to trace sources that vary. The example below is a sound level measurement with comparison to the Electron Microscope manufacturer’s specification, in third octave format. The specification line changes colour from grey to magenta if the specification is exceeded, as shown.

Chart Recorder

The chart program is used to record events that change relatively slowly. It simulates plotting on a paper chart which is up to 20 screen pages wide. It displays in page mode (one screen width at a time) or as a continuous scroll. The most recent 20 pages of data are retained in memory (2 hours 46 minutes at slowest chart speed). Controls for vertical range, chart speed and bandwidth are provided. Pan and zoom controls enable any section of the plot to be examined. You can mark events that occur during measurement of any chart, such as the movement of trains. The markers are exported with the results. The example below, in 4 channel mode, is a chart of the total Pk-Pk AC magnetic field in the 1Hz to 2500Hz range. The program is calculating the Pk-Pk values in real time and charting the result. It shows that the X field was steady at 1.05mG Pk-Pk and the Z field varied from 0.1 to 0.3mG Pk-Pk during the 100 second period of the chart. By selecting the narrow band option the program can chart the field at a specified frequency, e.g. 50Hz or 60Hz.

SCplot

SCplot is a comprehensive results editing program that enables results exported as text files or Matlab level 5 files from the Oscilloscope, Spectrum and Chart recorder programs to be formatted for published reports. It is particularly useful for formatting the large text files that result from long term data logging. It supports all the units and formats that are used in the Oscilloscope, Spectrum and Chart recorder programs. It enables units conversion and can post-process results with user specified formulas. SCplot can show multiple results measured at different times on a 3D waterfall plot and it can append plots to a document in Microsoft Word. The acoustic measurement shown on page 5 is reproduced below as an image exported from SCplot after formatting.

SC11 Wizard

The SC11 Wizard quickly and easily starts pre- defined measurements using one of the three measurement programs. It guides you through the choice of sensors, the instrument for which the environment is to be checked, the type of analysis and the type of measurement. The Wizard helps new or occasional users to get started with making measurements as simply as possible, using setup files that have already been created by an expert user. It also helps experienced users to organise their setup files.

SC11 Survey

SC11 Survey automates a complete survey by calling the SC11 instruments using Active X technology. It is like the SC11 Wizard except that it uses a macro that can run several measurements and automatically save the results. Survey guides you through the choice of sensors, a self test to ensure all the sensors are working and then the survey itself. Survey enables first-time users to set up the equipment and run a standard survey using a macro and setup files that have already been created by an expert user.

Downloads

SC11 Sensor Interface Analysis System Brochure

SC11 Sensor Interface Analysis System Brochure

DC Magnetic Field Sensor Option Brochure

DC Magnetic Field Sensor Option Brochure

If you would like to learn more about Site Survey Systems, contact our experienced technical team today. We would be happy to help you find the right solution for your needs. Contact us today!