Guralp Systems CMG-5T User Manual

Page 14

CMG-5T

2. Select the calibration channel corresponding to the

instrument, make any other choices you require, and click
Inject now. A new data stream, ending Cn (n = 0 – 7) or MB,
should appear in Scream!'s main window containing the

returned calibration signal.

3. Open a Waveview window on the calibration signal and the

returned streams by selecting them and double-clicking. The

streams should display the calibration signal combined with
the sensors' own measurements. If you cannot see the

calibration signal, zoom into the Waveview using the scaling
icons at the top left of the window or the cursor keys.

4. If you need to scale one, but not another, of the traces, right-

click on the trace and select Scale.... You can then type in a

suitable scale factor for that trace.

5. Click on Ampl Cursors in the top right hand corner of the

window. A white square will appear inside the Waveview at
the top left. This is in fact two superimposed cursors.

6. Drag one cursor down to be level with the lowest point of the

signal trace.

7. Drag the other down to be level with the highest point. In the

following example, a step function of 1 minute duration has

been applied to the Z3 stream. Note that ground movements
continue to be observed, superimposed on the returning

calibration signal.

Issue E