Sellin, A., Sack, L., Õunapuu, E. and Karusion, A. (2011), Impact of light quality on leaf and shoot hydraulic properties: a case study in silver birch (Betula pendula). Plant, Cell & Environment, 34: 1079–1087. doi: 10.1111/j.1365-3040.2011.02306.x
Rui Li, Cun-jun Li, Ying-ying Dong, Feng Liu, Ji-hua Wang, Xiao-dong Yang, Yu-chun Pan (2011), Assimilation of Remote Sensing and Crop Model for LAI Estimation Based on Ensemble Kaiman Filter. Agricultural Sciences in China, Volume 10, Issue 10, October 2011, Pages 1595-1602.
Jenny Ask, Jan Karlsson, Lennart Persson, Per Ask, Pär Byström, and Mats Jansson (2010), Whole-lake estimates of carbon flux through algae and bacteria in benthic and pelagic habitats of clear-water lakes. Ecology, July, Vol. 90, No. 7 : 1923-1932 (doi: 10.1890/07-1855.1).
Dirk Wiechers, Katrin Kahlen, Hartmut Stützel (2011), Evaluation of a radiosity based light model for greenhouse cucumber canopies. Agricultural and Forest Meteorology, Volume 151, Issue 7, 15 July 2011, Pages 906-915.
Grit Mehnert, Franziska Leunert, Samuel Cirés, Klaus D. Jöhnk, Jacqueline Rücker, Brigitte Nixdorf and Claudia Wiedner (2010), Competitiveness of invasive and native cyanobacteria from temperate freshwaters under various light and temperature conditions. Journal of Plankton Res. (2010) 32 (7): 1009-1021. doi: 10.1093/plankt/fbq033.
A PAR sensor and quantum sensor both measure photosynthetically active radiation (PAR). These terms are both used for sensors that measure light in the 400-700 nm waveband. The terms are interchangeable.
The LI-191R gives you the integrated PAR over the 1 meter length. This is ideal for measuring light interceptance by a plant canopy. Under canopies, there are areas that are completely sunlit, completely shaded, and areas that have some transmission of partial light through the leaves. The LI-191R gives an average PAR over all these conditions. The LI-190R measures light at a single point.
The "BNC" sensors terminate with BNC connectors and are most commonly used with the LI-1500 datalogger or LI-250A light meter. The BL sensors have bare leads that deliver a microamp current output. The SMV sensors are connected to a Standard Millivolt Adapter and have bare leads with a variable resister with a standardized 10 mV output at full scale.
The quantum sensors (LI-190R and LI-191R) measure light in the photosynthetically active radiation waveband. These sensors should be used to determine how much PAR a set of plants or canopy is receiving.
The LI-210R photometric sensor measures light as perceived by the average human eye. It should be used in any application that relies on human perceptions of light such as smart buildings or external lighting arrays.
Yes, we recommend that all our light sensors be recalibrated every two years. Recalibration can be done year-round for all sensors except the LI-200R. The LI-200R can only be calibrated between March 1 and September 30 each year.
This will depend on your data logger. If a microamp BNC connection is available, you can order the BNC termination option to provide this. If a two-wire connection is required, then use either the BL bare wire termination, SMV Standard Millivolt Adapter, or a millivolt adapter.
For the BL sensors, the brown wire is negative, the blue wire is positive, and the bare wire can be connected to ground to reduce signal noise. For the millivolt adapter, the green lead is positive and the blue lead is negative.