How does the recording and automatic triggering work?

During operation in fast mode the Enforcer is ready to record 4 seconds of high resolution data at any time. The recording can be started by two different mechanisms.

  1. Manual Recording: The recording can be started manually by pressing the red recording button  in the App.
  2. Automatic Triggering: Alternatively, the recording can be started automatically when the force exceeds the triggering threshold . The threshold value can be changed in the settings page in the App. This is a very convenient way to capture a dynamic event such as a drop test. The Enforcer will record 1 second prior to the trigger, which ensures that no important data will be lost.
As soon as the Enforcer has finished acquiring 4 seconds of data a message will pop up in the App allowing you to download the recording.
Below is a graph of a 155 kg drop test which was produced by using the automatic triggering function with the threshold set at 4.0 kN.
There are several aspects of this graph worth pointing out:
  1. There is no load on the system prior to the drop (i), which is typical of this kind of set-up. This implies that arbitrarily low threshold can be set. However, as the load settles there can be some static loading (iv) on the system and it is desirable that this static loading is below the trigger value (although not necessary as will be explained below). The lowest threshold value that can be set in the App is 2.0 kN.
  2. As the force approaches the trigger threshold (ii) we can see that we already have recorded just under 1 second of data. Moving the threshold value higher or lower has little impact on the timing as the force increases very rapidly in this region. This depends of course on the dynamics of the system. A stiff rope has a narrower peak than a very stretchy rope. The Enforcer will display LOADED while loaded above the trigger threshold and an oval sign while recording data.
  3. The peak value (iii) can be accurately determined from the graph due to high sampling rate and good resolution.
  4. Depending on how much damping is in the system, we typically see the force almost returning to zero before giving another smaller peak and then oscillating around the static loading (iv) due to the weight of the object.
If the static loading is higher than the threshold value then the automatic triggering is disabled, to avoid continuous recording. To record in this state you can press the recording button in the App or momentarily switch between fast and slow modes.

To disable the automatic triggering the threshold can be set to 20 kN.