Ceptometer

The AccuPAR model LP-80 is a lightweight, portable, linear photosynthetically active radiation (PAR) sensor. It lets you measure canopy PAR interception and calculate leaf area index (LAI) at any location within a plant or forest canopy. PAR data can be used with other climate data to estimate biomass production without destroying the crop. PAR is also important in determining other canopy processes; such as radiation interception, energy conversion, momentum, gas exchange, precipitation interception, and evapotranspiration.
The AccuPAR also uses radiation measurements and other parameters to accurately calculate leaf area index (LAI) non-destructively in real time, in the field.
Lightweight, Self-contained
The AccuPAR weighs a little over 1 pound ( 0.5kg). The attached controller, powered by four AA batteries, can be used to take measurements manually or can log data unattended for short periods of time. It stores 1 MB of data (over 2,000 readings) for later download and analysis.
Includes External Sensor
The included external PAR sensor can be used to make simultaneous above- and below-canopy PAR measurements. Using both the external sensor and the AccuPAR together allows you to get accurate PAR and LAI data in clear, partly cloudy, or overcast sky conditions.