How can I measure PAR light?

The PAR sensor described can be mounted inside the greenhouse in two ways: If the sensor is located next to the plant, we call this PAR plant. If the sensor is used to measure the PAR at the top of the greenhouse, we call this PAR weather.

Attention: the term PAR weather suggests that these PAR measurements are (always) taken outside the greenhouse. However, the sensor assembly described here, especially the mechanical part, is not suitable for outdoor applications.

The PAR sensor indicates the downward PAR radiation expressed in micromol/m 2 .s. PAR radiation (Photosynthetic Active Radiation) is also called “grow light” and includes the wavelength range between 400 and 700 nanometres. For comparison: a pyranometer measures global solar radiation in the wavelength range between ca. 300 and 2800 nanometres.

With the PAR crop module, the amount of PAR light in the greenhouse can be measured momentarily and summed. On the basis of these registrations the curtain settings can be adjusted.

The iSii + PAR module is optional from version 3.3.3.1 or higher. With this module you can control the PAR value under the (partly) closed curtain within a certain margin automatically. 

There is some maintenance: