This was again calculated numerically and curves fitted to the data with similar accuracy as above. The curves fitted are:

 

Given:

 

 

 

 

 

P ( x )

 

1

 

 

 

 

0.4.exp( 0.1. x ).( atan( 0.9.x )

 

0.95 )

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Q( x )

 

 

0.255. atan( x )

 

 

 

0.6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R( x )

 

 

exp(

 

x )

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P ( x ). LQ( x)

 

 

 

 

R( x ). ln( 1

 

 

 

 

L )

 

τ

spher

( x , L )

 

exp

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Diffuse light transmission (hemispherical response sensor)

 

Transmission

1

 

 

 

 

 

 

fraction

 

 

 

 

 

 

Leaf Angle

 

 

 

 

 

 

 

Distribution

 

 

 

 

Vertical

 

 

 

 

0.1

 

 

 

 

 

τ spher ( 0 , L )

 

 

 

 

 

Vertical

 

 

 

 

 

 

Spherical

τ spher ( 1 , L )

 

 

 

 

 

 

Horizontal

τ spher ( 1000 , L )

0.01

 

 

Spherical

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Horizontal

 

 

 

0.001

2

4

6

8

10

 

 

0

L Leaf Area Index

Modelling incomplete PAR absorption and scattering

Radiation models have been used for many years to calculate the effects of scattering in the canopy e.g. Norman & Jarvis (1975). Wood's model incorporates Campbell’s ellipsoidal leaf angle distribution and the effects this has on transmission of both Direct and Diffuse light.

The model splits the canopy into layers of LAI 0.1, extending to a sufficient depth to absorb all of the incident light. Incident light above the top layer was a known fraction of Direct (at a given zenith angle) and Diffuse light. The amount of light absorbed by a layer, assuming completely black leaves, was calculated. The fraction of this absorbed light re-emitted by the leaves was then assumed to be re-emitted in all directions uniformly (see Monteith & Unsworth, 1990, p85 onwards) .

The light level at any point in the canopy is then the light calculated assuming complete absorption, plus the sum of the light re-emitted by each canopy layer, attenuated by the intervening layers.

These calculations had to take full account of both horizontal and vertical light components. This involved an iterative solution and a lot of computer time. Finally, the light intensity as measured by a cosine corrected sensor was calculated.

SunScan User Manual v 1.05

LAI theory • 61

Page 60 Page 62
Page 61
Image 61
Delta Electronics SS1-UM-1.05 Modelling incomplete PAR absorption and scattering, Exp 0.1 . x . atan 0.9 Atan L Q Spher
Page 60 Page 62

SS1-UM-1.05 specifications

Delta Electronics has long been recognized for its innovative solutions in power and thermal management technologies. One of its notable products is the SS1-UM-1.05, a compact and efficient power supply module designed to meet the needs of a variety of applications, from industrial automation to telecommunications.

The Delta SS1-UM-1.05 is a key component in the company’s extensive portfolio, providing reliable and stable power supply for both demanding and sensitive electronic equipment. One of the main features of this module is its high efficiency, which typically exceeds 90%. This not only minimizes energy consumption but also reduces heat generation, making it an ideal choice for applications where thermal management is crucial.

Another significant characteristic of the SS1-UM-1.05 is its wide input voltage range, which allows it to operate effectively in various environments. The module supports a voltage range from 90 to 264 VAC, ensuring consistent performance even in fluctuating supply conditions. This versatility makes it well-suited for global applications, accommodating different electrical standards and requirements.

The SS1-UM-1.05 also boasts a compact footprint, which is essential for space-constrained installations. Its design emphasizes not only performance but also ease of integration into existing systems. The module provides multiple output voltage options, allowing it to cater to specific power requirements, whether it be for industrial machinery or consumer electronics.

In terms of technologies, the SS1-UM-1.05 incorporates advanced power conversion technologies that enhance its overall performance. It features overload protection and thermal shutdown mechanisms to safeguard both the module and the equipment it powers from potential damages due to electrical faults. Moreover, it has low electromagnetic interference (EMI) emissions, which is crucial for environments sensitive to electrical noise.

The SS1-UM-1.05 is also designed with a robust enclosure that adheres to stringent safety and environmental standards. This enhances its durability and reliability, ensuring it can withstand harsh operating conditions. With these features, Delta Electronics demonstrates its commitment to delivering high-quality products that meet the evolving needs of industries worldwide.

Overall, the Delta SS1-UM-1.05 power supply module is an exemplary solution for those seeking a reliable, efficient, and compact power source. Its advanced features and technologies make it an indispensable component in modern electronic systems.
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