What is the difference in between the LAI-2000 and LaiPen LP 110?
LAI-2000 measures the attenuation of diffuse sky radiation at five zenith angles simultaneously, it has five detectors. The correct way of measurement is conditioned by attaching an appropriate view cup to hide foreign objects in the field of view. Our LaiPen is designed to avoid the system of view restrictor cups. This means it has a single view cup and a single detector and the four subsequent angles must be measured separately with the help of build-in electronic inclinometer and visual-acoustic indicator. In LaiPen, the permanent restricting cup has restriction angle 160 along x axis and 1120 along y axis, which is different from LICOR LAI 2000.
Can I correct measurements for clumping effects in the LaiPen LP 110?
The only measurement you do with LaiPen is irradiance. In this respect, you can not correct measured irradiance values for clumping during measurement, but you can correct your calculation of LAI index afer you download irradiance values from LaiPen to computer.
What is the exact geometry/configuration of the ring sensors in the LaiPen LP 110?
There are no ring sensors in LaiPen. Instead, the LaiPen device is equipped with a single wide-angle optical sensor used in conjunction with a cup restricting 160 / 1120 angle sector. All angles (in multiple angle measurement mode) are measured only with one sensor. The other four angles are obtained by subsequent inclinations of the device from zenith angle, which is controlled by electronic inclinometer with pre-defined five angle positions.
Can I exclude specific rings from the LaiPen LP 110 computation, or change path lengths of different rings (not homogeneous canopy) or measure single trees?
In multiple-angle measurement mode you always measure all five angles. But since the data you download from the LaiPen to computer for further processing are only uncomputed raw values, exclusion of any measurement would be possible. It is not possible to change the path lengths - these are fixed. And the single trees measurement, for sure it can be done.
The website claims we can measure under different sky conditions with the LaiPen LP 110, but the way the instrument deals with this is unclear?
The dual sensor mode of measurement alows to estimate reference values for each particular time of measurement in changing weather conditions much more efficiently than the single sensor mode. The way how single sensor mode of measurement deals with this issue is decribed in the first version of Lai Pen manual (chapter 7.A. Single Sensor Mode of Measurement). The computation in case of dual sensor mode of measurement is described in the second attached file named: “Dual mode_ Introduction.pdf”, which is not included in the first version of manual.