Measure Canopy PAR, Calculate Leaf Area Index
The AccuPAR LP-80 Ceptometer is a lightweight, portable, linear array of photosynthetically active radiation (PAR) sensors for non-destructive leaf area index (LAI) measurements. It allows you to measure canopy PAR interception and calculate 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. With the AccuPAR there is no need to wait, it uses radiation measurements and other parameters to accurately calculate leaf area index in real time, in the field.
The AccuPAR weighs a little over one pound (0.5kg). The attached controller, powered by four AA batteries, can be used to take measurements manually or log data unattended for short periods of time. It stores over 2,000 readings for later download and analysis.
Above Canopy Sensor
The included external PAR sensor can be used to make simultaneous above, and below-canopy PAR measurements as a reference for intercepted light. 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.
|DATA STORAGE CAPACITY||1 MB RAM (over 2,000 measurements)|
|NUMBER OF SENSORS||80|
|PAR RANGE||0 to > 2,500 μmol m-2s-1|
|RESOLUTION||1 μmol m-2s-1|
|PROBE LENGTH||84 cm|
|OVERALL LENGTH||99 cm (40 in)|
|UNATTENDED LOGGING INTERVAL||User selectable, between 1 and 60 min|
|INSTRUMENT WEIGHT||0.56 kg (1.23 lbs)|
|DATA RETRIEVAL||Direct via RS-232|
|KEYPAD||7 key, menu-driven|
|OPERATING ENVIRONMENT||0-50°C (32-122°F), 0-100% relative humidity|
|EXTERNAL PAR SENSOR CABLE LENGTH||5 meters|
|INTERFACE CABLE||RS-232 cable|
|POWER||Four AAA Alkaline cells|
|MINIMUM SPATIAL RESOLUTION||1 cm|
WW Wilhelm, K Ruwe, MR Schlemmer. 2000. Comparison of Three Leaf Area Index Meters
In a Corn Canopy. Crop Sci. 40:1179-1183
For a reprint of this article, please contact Decagon.
Extension Cable for External PAR Sensor
7.6m (25 foot) cable with locking 3-pin circular direct connections to be used with the LP80’s external PAR sensor.
External PAR Sensor
(Included with each LP-80)
2 meter cable with connector for direct connection to the ceptometer’s external port.
Calibrated to provide an output of about 0.1 mV per µmol m-2 s-1, calibration label provided.
- Beam Fraction Calculation in the LP80
- How the LP80 Measures Leaf Area Index
- Measuring χ Value
- AccuPAR Used in Study of Tree Shade in Ocala, Gainesville
- Is it Time to Recalibrate Your AccuPAR LP-80 External Quantum Sensor?
- Light Interception and Biomass Production
- Photosynthesis and Canopies
- Simple Models for Carbon Assimilation by Plants
- Using AccuPAR to Find Crop Coefficients for Irrigated Grapevine Production
- Use of the AccuPAR Ceptometer to Quantify Effects of Riparian Vegetation Removal on Stream Energy Balance