Adequate protection against injuries caused by blades is essential for lawnmowers. With the method described below, the time from switching off the lawnmower to the stopping of the cutting means is determined. Lawnmowers are switched off automatically with the release of the blade operator presence control. The cutting means must come to an ultimate standstill within a certain period of time depending on the cutting with as follows:

For lawnmowers with a cutting width up to and including 600 mm, the cutting means shall come to a standstill from highest rotational speed within 3 seconds after the release of the blade operator presence control. For devices with a cutting width exceeding 600 mm, the permissible time to standstill is 5 seconds.

The accuracy of measurement has to be 25 ms.

The VDE test system was designed and manufactured at the VDE Testing and Certification Institute using standardized components. The lawnmower is mounted on an especially designed testing table. Below the cutting means of the lawnmower, a video camera with a system of sensors in mounted allowing the determination of the time. The evaluation of the signals is done through adequate software in a personal computer connected.

Time is determined by a counting device using the software. Testing is performed and recorded in accordance with the standards DIN EN 50338/VDE 0700 Part 771:2001-09 "Particular requirements for pedestrian controlled battery-operated lawnmowers" and DIN EN 60335-2-77/VDE 0700 Part 77:2001-09 "Particular requirements for pedestrian controlled mains-operated lawnmowers".

The method of the stopping time determination (verification of standstill) is only one out of 50 individual tests which a lawnmower is subjected. Only with positive result obtained in all tests, the treasured VDE Marks License will be granted. Products bearing a VDE Certification Mark guarantee the highest level of electrical and mechanical safety to the consumer.