The run-off measuring system consists of various components that can be used in a modular fashion. The measuring system is used to record and sample surface runoff and the erosion loads it contains. The basic equipment is the autosampler for surface run-off, consisting of an erosion vessel, tipping counter and data logger, among other things. Other components are the measuring plot limitation, the collecting gutter, the divider system, hoses and a bypass tipping counter. There are no bottlenecks in the entire system that could clog, cause backwater or slow down the flow rate. The erosion material can thus be unhindered transported  in the flowing water.

Measuring plot limitation, collecting gutter, and dividing system

The measuring plot limitation is a system for the medium and long-term demarcation of a 30 m² (3 m x 10 m) measurement area for collecting surface run-off. In combination with the collecting gutter and the dividing system, the surface run-off can be collected from the plot area and routed via the dividing system to the tipping counters to measure the runoff.

The collecting gutter consists of a stainless-steel angle construction that is firmly anchored in the ground. The collecting gutter is buried in such a way that no sediment load can accumulate. The cover of the collecting gutter prevents rainwater from entering the collecting gutter.

A separation system is required to limit the flow rate at the inlet of the autosampler for surface run-off. The collecting gutter directs the run-off water to the dividing system. The dividing system contains a perforated plate to keep out large foreign bodies and prevent animals from entering. The dividing system has two outlets at two different heights for connecting tipping counters. The lower connection leads to the tipping counter of the autosampler for surface run-off. When the capacity of the tipping counter is reached, the water flows out via the upper outlet of the dividing system to the bypass tipping counter. The data from both tipping counters is recorded by the data logger.

Autosampler for surface run-off

The surface run-off is fed into the autosampler via the tipping counter on the erosion vessel. A double-ring bottle magazine is located in the erosion vessel. A processor-controlled swivel arm fills the inner and outer bottle positions (maximum 12 bottles each) fully automatically or empties the collected surface water via the outlet of the erosion vessel.

The sampling frequency is adapted to the discharge intensity by means of a microcomputer to ensure that the various discharge events can always be optimally recorded. In the case of low run-off volumes, the entire surface run-off captured by the collecting gutter is filled as a sample in order to obtain the largest possible sample quantity. In the case of a high run-off event, on the other hand, sample water is only collected at adjusted time intervals. The remaining water is dumped again after the quantity has been recorded. This prevents all sample bottles from being filled too quickly and ensures that the samples are distributed over the entire discharge event.

The autosampler for surface run-off is installed below the measuring area in order to generate the flow solely due to the difference in height and not to be dependent on pumps. This creates a free flow and keeps energy consumption to a minimum.

Comprehensive picture of runoff and erosion processes

In combination with meteorological and soil hydrological measuring stations, the run-off measuring system can be used to obtain a comprehensive picture of run-off and erosion processes.

Item no.: 2011000 - Autosampler for surface run-off:

• 1 x Erosion vessel with removable cover
• 1 x Double ring bottle magazine for 24 amber glass bottles
• 24 x amber glass bottles 1.000 ml
• 2 x electric motor drives for swivel arms and rotating arm
• Position sensors and proximity switch
• 1 x Inlet and outlet
• V2A - Water guide elements with 3-way switching
• 1 x V2A-tipping counter 1 l
• 1 x logger housing with microprocessor control, integrated data logger
• 1 x software UGTLog
• 1 x UGT data cable
• 2 x Removable battery with a charger