For gravity tide monitoring applications, you can use the LaCoste and Romberg TIDEDAQ.EXE data acquisition system, or a data logging system of your choice.

The raw analog voltage output of the Feedback system is available on the Analog Output Connector ("Recorder Jack") on the side of the gravity meter. Digitizing with differential-input logging systems is advisable to avoid ground loop problems.

 

 

 

 

 

After some time, the gravity meter will drift towards the end of the range that can be balanced by the feedback system. At this time, the nulling dial must be reset. The drift of most meters is in a positive direction, and drift rates are typically less than one milligal per month after a meter has been on heat for some time. Drift rates may be higher for new meters, or if the meter has been off heat for some reason. Since the range of the feedback system is typically about 2 milligals (when operated at 10 volts), the nulling dial may need to be reset every month or two. If you are using the LaCoste and Romberg TIDEDAQ.EXE data acquisition system, AND if the optional Stepper Motor is installed, the software offers a feature to automatically reset the dial by 0.5 dial turns when necessary.