Chapter 1. Introduction
The CMG-EDU is an ultra-compact single-axis broadband seismometer designed specifically for educational uses. It is available in either vertical or horizontal form.
The CMG-EDU is ready to record ground movements as soon as you provide it with power. It does not have to be unlocked or centred as long as its base is within 3 ° of horizontal. For the best results, however, you should install where possible on a hard, near-horizontal surface, preferably underground. See “Choosing a location” in Section 2.1 for recommendations. Also supplied is a Güralp Systems CD24E1 compact single-component digitizer, and a GPS unit.
Each package is delivered with a detailed calibration sheet showing its serial number, measured frequency response in both the long period and the short period sections of the seismic spectrum, sensor DC calibration levels, and the transfer function in poles/zeros notation.
1.1 Unpacking and handling
The CMG-EDU instrument is delivered in a single case, with specially designed packaging. You should reuse this case whenever you need to transport the sensor. Please note any damage to the packaging when you receive the equipment, and unpack on a safe, clean surface. The package should contain:
the seismometer with attached signal cable;
the GPS unit with attached data cable;
a blue power/data cable;
a calibration and installation sheet, and
You will need to provide your own 12–24 V DC power supply, and a Windows or Linux PC for recording the data.
1.1.1 Handling notes
Although the CMG-EDU is relatively rugged, it can be damaged if mishandled.
Do not bump, kick or drop the sensor.
Do not kink or walk on the data cable, nor allow it to bear the weight of the sensor.
Do not ground either of the signal lines from the instrument.
If any component is missing or appears damaged, contact Güralp Systems immediately (see Chapter 6, “Troubleshooting and help”.)