A sensor arrangement may be used to measure properties, such as optical properties, of a device arranged to process substrates. The sensor arrangement includes a substrate having the following: a plurality of sensor elements provided as an integrated circuit in the substrate, for each one of the plurality of sensor elements associated electronic circuitry comprising a processing circuit connected to the sensor element and an input/output interface connected to the processing circuit, and a power supply unit configured to supply operating power only to the electronic circuitry associated with one or more of the plurality of sensor elements which are in use. The at least one sensor element and possibly the processing electronics, the input/output unit, and/or the power supply unit may be provided as one or more integrated circuits or other structures in the substrate.