Abstract: The device and method for measuring effect of soiling on a photovoltaic device includes a device in which a photovoltaic device (reference solar cell, solar cells, PV module, etc.) may be shifted between partially and fully enclosed compartments in quick succession for measurements of the same device (1) when directly exposed to illumination or solar radiation; (2) when placed under a glass or transparent cover maintained cleared or cleaned of soil; and (3) when placed under glass or transparent cover left exposed to natural outdoor soiling, or attenuated using simulated soil that is not periodically cleaned. The measurements may be of short circuit current (Isc), maximum power (Pmax), which are used to calculate the to soiling ratio. If the transparent covers have substantially identical optical properties and meet identical requirements for positioning relative to the DUT, only measurements (2) and (3) are required, and calculations of the soiling ratio are simplified.