The main part of the a Vernier PAR sensor is a water proof sensor head. The end of the cable is attached to a voltage amplifier located inside a black electronics box. The sensor head consists of an acrylic lens, filter, photodiode, and signal processing circuitry that is mounted in a waterproof aluminum housing that can be used for continuous PPFD measurements. The sensor head is cosine corrected. This allows the sensor to maintain accuracy when light hits the sensor head at different angles. Light hitting the lens of the sensor head produces an analog voltage that is amplified by the electronics box. This amplified voltage is then converted to PPFD by the data-collection software.