The Optimus/Optimus+ sound level meters provide Pause and Back-Erase function which can be used during a measurement.
The Pause/Back-Erase function is only available if this has been enabled in the instrument menu.
When the Pause function is enabled in the menu, the Stop button is replaced by the Pause/Stop button. This also enables the Back-Erase function, the duration of which can be set in the menu.
Press once to pause/back erase and twice to stop, or alternatively press and hold for three seconds to stop.
When the pause function is activated, the time history data will be coded and will be displayed in the NoiseTools software. The time or times that the pause function was active will be shown with a grey background.
An example of this is shown below:
The Back-Erase function allows a section of the measurement to be removed from the data used to calculate the overall values.
An example of this would be if, during the measurement of cars on a road, a large truck passed by the measurement location. If the intention was only to measure cars, the truck can be excluded from the overall measurement data by pressing the Pause button and then using the Back-Erase to remove a preset section of noise.
The time that the pause button was pressed, along with the Back-Erase duration, will be excluded from the calculation of the overall noise values such as the Leq, Lmin, Lmax, LPeak, and the 1:1 and 1:3 Octave Band overall values.
The duration of the Back-Erase can be set to between 1 and 30 seconds using the menu and can also be configured in the NoiseTools software. If the Pause function is disabled, the Back-Erase function is also disabled.