Task

A customer on the other side of the world asked us for automatic samplers that can be used in a vast desert region. Our first reaction: “In the desert? What is the device supposed to do there?”

The special requirement is that heavy rain events occasionally occur in this desert. Although they are localised, the runoff from these torrential downpours leads to sometimes heavily polluted tributaries that are located far away.

Our devices should be able to reliably record these polluted tributaries. They must be able to wait for months in stand-by mode until a discharge event occurs. As soon as this happens, the devices should take a 2-litre sample and register the exact time of the event.

These requirements have to be met in extreme temperatures, ranging from sub-zero to almost 50°C in the hot desert sun.

Our solution

We have developed a simple device based on the principle of vacuum sampling. It requires no control and consumes no power in stand-by mode. It is also equipped with components that can easily cope with the harsh “desert climate” over long periods of time.

Function

When a drainage event occurs, the device automatically recognises this and activates the power supply. The device then takes a 2 litre sample using the vacuum principle and then switches off completely. At the time of sampling, the date and time are recorded via an integrated digital clock.

The sample is safely stored in a special container to prevent evaporation.