SC11 Basic System Product Description

The SC11/Basic/USB is the latest version of our popular site survey equipment. It features data acquisition and pre-processing by an embedded microcomputer in the magnetic field sensor, 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 Basic system includes a three axis AC magnetic field sensor, an accelerometer and a sound level meter. An optional flux gate magnetometer can be added to measure DC magnetic fields. The software suite consists of three virtual instruments, an oscilloscope, a spectrum analyser and a chart recorder plus a comprehensive results plotting program “SCplot”. During measurements, all results are displayed graphically on the laptop screen.

The system is powered from the laptop except for the sound level meter and magnetometer which have their own batteries. It is supplied in a rugged custom carrying case.

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.

Magnetic Field Sensor
The three axis magnetic field sensor is derived from sensors used in the Spicer Consulting range of magnetic field cancelling systems. It contains a three-axis inductive pick up coil (X, Y, & Z) connected to precision analog integrators, to measure AC magnetic fields. The measurement range is 80 mG pk-pk with a bandwidth of 1 Hz to 20 kHz and the total noise limit in the band is 3µG RMS. Post-processing in the laptop computer enables the low frequency limit to be extended to 0.1Hz with minor increase in the 1/f noise limit. The measurement accuracy is ± 1%.

The sensor has two inputs for connecting external signals. The first input is specifically for the Wilcoxon 731A accelerometer. It provides the constant current load & power supply for the 731A. The second “Aux” input has a BNC connector. It is used with the sound level meter and the Meda magnetometer and other sources such as the video output from an SEM in spot mode. These two inputs can only be used one at a time. The software selects which is used

Sound Level Meter
The sound level meter supplied is a Techcessories model 33-4050 for general purpose sound measurements. It can measure from 50 to 126 dBA or dBC on its internal meter.

Accelerometer
The accelerometer supplied is a Wilcoxon Research model 731A, with a measurement range of 200 mg's pk-pk and a bandwidth of 0.1 Hz to 500 Hz in this system. The accelerometer is suitable for the measurement of extremely low level vibrations. The accelerometer measures along one independent axis.

The accelerometer can be rotated to measure three orthogonal axes while standing on a horizontal plane.

Flux Gate Magnetometer
The optional flux gate magnetomer is a µMAG-01N from MEDA. It measures one axis magnetic fields from DC to 400 Hz, with a maximum range of ±2000 mG and a meter resolution of 0.01 mG on the most sensitive 20 mG range.