Vesda VSP-002 Standard Display ModuleThe VESDA VLP detector is the central element of the VESDA ASD product range. Using unique detection principles, the VLP has an alarm sensitivity range of 0. 005% 20% obscuration m (0. 0015%6. 25% obscuration ft). The VLP is classed as a Very Early Warning Smoke Detector, which means that it detects fire at the earliest possible stage and reliably measures very low to extremely high concentrations of smoke.