The following variables are continuously monitored at the Hydrograce project sites:
* Precipitation, using a Hydrological Services TB4 raingauge (with a resolution of 0.2mm).
* Soil moisture, using three Campbell Scientific CS-616 soil moisture probes (at 0-30cm, 30-60cm, and 60-90cm) and one Stevens Hydra-Probe (at 0-5.7cm).
* Soil temperature, using a Hydra-Probe thermistor sensor at 3cm and a T-107 thermistor at 15cm.
* Groundwater, using an Odyssey capacitance probe (of 2m length).

The following variables are periodically monitored at these sites (mostly for field calibration of the continuous instuments):
* Gravity, using a Scintrex CG-3M Autograv relative gravimeter.
* Soil moisture, using three connector TDR soil moisture probes (at 0-30cm, 0-60cm, and 0-90cm) and a Trase unit.
* Soil moisture, using a CPN 503DR Hydroprobe neutron moisture meter (measuring from the surface to groundwater or bottom of piezometer).
* Groundwater, using an electronic water level measuring tape.

The image to the right shows the instrumental array. Click on the image for further details of each instrument.