Calibrating A Gecko Sma-Hr - Gecko Compact Product User Manual

Calibrating a Gecko SMA-HR

The Gecko SMA-HR has an in-built calibration procedure whereby the processor sends a 5Hz
sine wave of 1V amplitude to excite the sensor components. By comparing the sensor
response over time you can check that your sensor is still within specification.
After running the calibration routine using the feature discussed earlier in this user manual,
open the files from your SD card's continuous data archive that correspond to the time you
performed the calibration to see how the sensor responded.
The original Gecko SMA-HR calibration response should look like this:
The 2020 Gecko SMA-HR Pro calibration response will have inverted signal on the horizontal
components due to the inverted orientation of the sensors in the casing – this is normal.
Remember that you can always rotate your signals in Waves during data analysis to correct
for stations that were installed at an orientation where the arrow was not pointing North.
The Gecko Prism contains a very robust but very sensitive velocity sensor. Once the
seismograph is powered on, be careful not to move the sensor. It should be bolted down to
avoid accidental movement. If you accidentally knock the sensor and the signal levels start
clipping, simply turn the unit off for a second and then on again to quickly settle the sensor.
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