Kipp&Zonen CMA 6 Albedometers - Manual (Page 21)

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Instruction Manual - CMP/CMA series
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Below is a brief description of the accessories available for CMP series pyranometers. Detailed information can be found on our
website, where the brochures and manuals for these accessories can be viewed and downloaded. The only accessories available
for the CMA series albedometers are the CMB 1 mounting bracket and the AMPBOX 4 to 20 mA signal amplifier (two amplifiers
are required).
3.1 Diffuse radiation measurement
For measuring diffuse radiation a shading device is required. Kipp & Zonen can offer several options for CMP pyranometers:
Shadow ring CM 121B for a CMP 3 or an unventilated CMP 6, CMP10, CMP 11, CMP 21 or CMP 22
Shadow ring CM 121C for a ventilated CMP 6, CMP10, CMP 11, CMP 21 or CMP 22
This shadow ring needs to be adjusted manually every 3-5 days and corrections made for the part of the sky obscured by the ring.
An automated and more accurate way to measure diffuse radiation is to use an automatic sun tracker fitted with a shading mech-
anism:
2AP sun tracker + shading ball assembly
SOLYS 2 sun tracker + shading ball assembly
3.2 Ventilation
To further improve measurement accuracy of the CMP 6, CMP10, CMP 11, CMP 21 or CMP 22 pyranometers the CVF4 ventilation unit
can be used. CVF4 operates from 12 VDC, has a tacho pulse output to monitor the fan speed, and both 5 Watt and 10 Watt heaters.
The advantages of a CVF4 are:
Lower thermal offsets
No precipitation or condensation on the dome
Less dirt on the dome
Frost, snow or ice can be melted
Less frequent cleaning required
No ventilation unit is available for the CMP 3 pyranometer or the CMA 6 and CMA 11 albedometers.
3.3 Mountings
For mounting pyranometers the following plates and brackets are available:
Mounting rod for CMP 3
CMF 1 mounting fixture with rod for mounting one or two unventilated CMP 6, CMP10, CMP 11, CMP 21 or CMP 22
CMF 2 mounting plate with rod for mounting one or two ventilated CMP 6, CMP10, CMP 11, CMP 21 or CMP 22
CMB 1 mounting bracket to fix and adjust a mounting rod to a mast, pole or wall
Adjustable tilt mounting kit allows tilting of a CMP pyranometer (e.g. in the same plane as a PV panel), It has a
clear scale for setting the desired angle.
3.4 Glare screen kit
When a CMP 6, CMP10, CMP 11, CMP 21 or CMP 22 pyranometer is mounted looking downwards, to measure reflected radiation,
it should be fitted with the glare screen kit. The screen blocks radiation coming from the 5 ° below the horizon of the pyranometer,
to prevent direct illumination of the domes by the sun at sunrise and sunset. CMA albedometers have an integral glare screen.
3. Accessories
3.5 Cables
As standard a 10 m long cable with a pre-wired waterproof connector plug is supplied. Optional longer cables are available, or
a loose connector only for you to fit to your own cable.
10 m cable with connector (standard)
25 m cable with connector
50 m cable with connector
Loose connector without cable
100 m cable with connector (on special request)
Note 100 m is the maximum length of cable that does not significantly affect the radiometer sensitivity and other
characteristics.
3.6 AMPBOX
For customers who require an industry standard output, or to use long cables, the AMPBOX signal amplifier converts the low
level radiometer voltage output to a 4 to 20 mA current loop signal. For a CMA albedometer, two AMPBOX units are required.
When supplied with a new pyranometer or albedometer the AMBOX is adjusted such that the radiometer/AMPBOX pair gives
an output where 4 to 20 mA represents 0 to 1600 W/m².