Kipp&Zonen CMA 6 Albedometers - Manual

CMP series • Pyranometer
CMA series • Albedometer
Instruction Manual
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Throughout this manual the following symbols are used to indicate to the user important information.
General warning about conditions, other than those caused by high voltage electricity, which may result in physical
injury and/or damage to the equipment or cause the equipment to not operate correctly.
Note Useful information for the user
1.1 Product overview
According to International Standard ISO 9060:1990 and the World Meteorological Organisation (WMO) a pyranometer is the
designated type of instrument for the measurement of hemispherical (global or diffuse) solar radiation integrated over the
wavelength range from 0.3 to 3 µm (300 to 3000 nm). All pyranometers within the CMP series are compliant with one of the
classes specified by the international standard.
The albedo of a surface is the extent to which it diffusely reflects short-wave radiation from the sun in the wavelength range from
300 to 3000 nm. It is the ratio of the reflected radiation to the incoming radiation and varies from 0 (dark) to 1 (bright). As an
indication, albedo is about 0.15 for grass, 0.5 for dry sand and 0.8 for fresh snow.
CMA series albedometers consist of two pyranometers. The upper measures incoming global solar radiation and the lower
measures solar radiation reflected from the surface below. When the two signal outputs have been converted to irradiance in W/m²,
the albedo can be simply calculated.
This manual, together with the instruction sheets, provide information related to the installation, maintenance, calibration,
product specifications and applications of the CMP series pyranometers and CMA series albedometers.
If any questions should remain, please contact your local Kipp & Zonen representative or e-mail the Kipp & Zonen customer and
product support department at:
[email protected]
Please go to www.kippzonen.com for information about other Kipp & Zonen products, or to check for any updates to this manual.
1.1.1 The pyranometer and albedometer
The CMP series instruments are high quality radiometers designed for measuring short-wave irradiance on a plane surface
(radiant flux, W/m²) which results from the sum of the direct solar radiation and the diffuse sky radiation incident from the
hemisphere above the instrument. The CMA series also measures the amount of the incoming radiation which is reflected by the
surface below.
There are six models in the CMP series; CMP 3, CMP 6, CMP10, CMP 11, CMP 21 and CMP 22; and two models in the CMA series,
CMA 6 and CMA 11.
To achieve the required spectral and directional characteristics CMP series pyranometers and CMA series albedometers use
thermopile detectors and glass domes. They have built-in bubble levels and the pyranometers have adjustable levelling feet.
Snap-on sun shields reduce solar heating of the housings. Albedometers have a mounting rod fitted and an integral glare-
shield to prevent direct sunlight from below the horizon entering the lower pyranometer. The waterproof connectors have
gold-plated contacts.
The instruments are normally delivered with a waterproof plug pre-wired to a high quality signal cable, typically this is 10 m
long but other lengths are available. The instruments can also be ordered with a plug only, for the user to fit their own cable.
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CMP pyranometers and CMA albedometers do not require power to operate. Radiation falling onto the sensing element produces
a small analogue output voltage.
CMP 3 is smaller and lighter than the other CMP series pyranometers. It features a 64-junction thermopile sensing element with
a highly absorptive and spectrally flat black coating to capture incoming radiation and convert it to an electrical signal. This
detector is protected by a high quality glass dome which is 4 mm thick. The housing is completely sealed.
CMP 6 uses the same sensing element as CMP 3 but has improved performance due to the double glass dome construction and the
increased thermal mass of the larger housing. The glass used has better transmission of ultraviolet radiation than the CMP 3 glass.
The two high quality concentric domes, 2 mm thick, reduce directional error and improve thermal isolation. The radiometric
levelling is more accurate and CMP 6 has a drying cartridge with replaceable desiccant.
CMP10 and CMP 11 have a 32-junction thermopile sensing element which features faster response, better linearity and a wider
measurement range than the CMP 3 and CMP 6. CMP10 and CMP 11 have built-in temperature compensation. The CMP10 has
internal desiccant that lasts for 10 years and the CMP 11 has a removable drying cartridge.
CMP 21 is similar to the CMP 11 but has individually optimised temperature compensation and a sensor is fitted to monitor the
housing temperature. Each instrument is supplied with its own temperature and directional response for post-processing of
recorded data by the user. A Pt-100 temperature sensor can be ordered instead of the standard 10 kΩ thermistor.
CMP 22 has all the features of CMP 21 but uses two 4 mm thick very high quality quartz domes for a wider spectral range and reduced
thermal offsets. Because of the high optical quality and refractive index of these domes the directional error is greatly reduced.
CMA 6 is an albedometer comprised of two CMP 6 sensing element and dome assemblies in a single housing with two signal
outputs on one signal connector.
CMA 11 uses two of the same sensing elements as fitted to the CMP 11 pyranometer, for similarly improved performance over the CMA 6.
Features and specifications of the CMP and CMA instruments are explained later in this manual.
1.1.2 International Standards
CMP 3 exceeds the requirements of ISO 9060:1990 for a Second Class Pyranometer.
CMP 6 and CMA 6 are fully compliant with the requirements of ISO 9060:1990 for a First Class Pyranometer.
CMP10, CMP 11 and CMA 11 are fully compliant with the requirements of ISO 9060:1990 for a Secondary Standard Pyranometer.
CMP 21 and CMP 22 significantly exceed the requirements of ISO 9060:1990 for a Secondary Standard Pyranometer.
CMP series pyranometers and CMA series albedometers are calibrated in accordance with Annex A.3 of ISO 9847 ‘Calibration of
Field Pyranometers by Comparison to a Reference Pyranometer’. Annex A.3 refers to ‘Calibration Devices Using Artificial Sources’.
Calibrations are traceable to the World Radiometric Reference (WRR) in Davos, Switzerland.
CMP series pyranometers comply with IEC 60904-1 ‘Photovoltaic devices - Part 1: Measurement of Photovoltaic Current-Voltage
Characteristics’.
1.2 The CMP 3 pyranometer
1.3 The CMP10 pyranometer