Frequently Asked Questions
How is rainfall most accurately measured?
The World Meteorological Society recommends that weather stations are placed at a distance away from any nearby obstacles that is at least six times the height of the obstacles as the most optimal way to ensure accurate readings, this can prove impossible on a lot of orchards and farms due to space requirements so some compromise may be required.
The rain gauge needs to be level to operates accurately. There is a bubble level built into the base of your rain gauge you can use this to help with leveling.
Also see info on rain gauge choice
Which rain gauge should I choose?
Davis - The Davis rain gauge is our entry level offering. The gauge uses a self-emptying tipping spoon type mechanism with a clip in filter to reduce blockages and provision for optional bird spikes
Harvest - The Harvest rain gauge has been designed with a larger 203mm diameter catchment funnel, has a sturdy stainless steel construction and a large stainless steel sieve type filter and is factory calibrated with extra calibration check at Harvest.
Hyquest TB series - The TB Series is designed for industrial/meteorological purposes where a very high accuracy of measurement is required.
How often should I clean my rain gauge?
Your rain gauge should be cleared of debris at least every 6 months and vegetation or other obstructing objects kept at a reasonable distance. Clean cobwebs and insects from inside the bucket, clean the tipping bucket and check that it tips freely with very little force i.e. you should be able to blow on it to make it tip.
We have found that placing a Harvest insect repellent inside of the rain gauge can help prevent insects living inside the rain gauge.
Why is my neighbours rain gauge reading different to mine?
Rain gauges a even few metres apart at a similar level can differ by 10 percent as the capture area of a rain gauge is not large enough to cope with the statistical variation of rainfall. To try and overcome this variation very accurate scientific rain gauges have been made that have a capture diameter of one metre which is impractical for normal use. It is also important to note that the higher the rain gauge is mounted off the ground the less rain it will read due to be affected by wind.
Soil Moisture Monitoring
Why should I have more than one soil moisture level?
We recommend installing soil moisture sensors at two levels (Pasture at 100mm & 300mm, Orchard and Vineyards at 300mm & 600mm ) at each location of soil moisture monitoring to give a good representation of the soil moisture throughout the root zone.
How many soil moisture monitoring sites should I have?
We don’t have a specific, sites per x-hectares, way of looking at this the amount of monitoring sites is purely determined by different soil types across your property or how many different irrigation zones you may have.
Where should I place my sensors?
Depending on property use, we recommend different positioning. On a farm we recommend placing sensors close to the fence line so the ground directly above them won’t be trampled by stock. In Vineyard and orchard applications we recommend placing the sensors as close to the plants root zone as possible inside the irrigated area.
What is TDR and is it accurate?
TDR stands for Time Domain Reflectometry which is a technology that measures the time it takes for a radio pulse to travel to the end of a wave guide and reflect back to the base of the wave guide, the soil moisture reading is produced based on this measurement. The Acclima TDR sensor which we supply is a research grade sensor which is not sensitive to conductivity, therefore does not require calibration.
The Accuracy figures are as follows:
Reading Range: 0 to 100%
VWC Reporting Resolution: 0.1%
VWC Repeatability (RMS deviation): 0.07%
Coarse and medium textured soils: ±1 percentage point
Fine textured soils: ±2.5 percentage points