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Related Manuals for Kipp & Zonen CM 11
Summary of Contents for Kipp & Zonen CM 11
- Page 1 Kipp & Zonen INSTRUCTION MANUAL PYRANOMETER / ALBEDOMETER...
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Page 2: Important User Information
IMPORTANT USER INFORMATION IMPORTANT USER INFORMATION Reading this entire manual is recommended for full understanding of the use of this product. The exclamation mark within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance instructions in the literature accompanying the instrument. -
Page 3: Declaration Of Conformity
According to EC guideline 89/336/EEC 73/23/EEC Kipp & Zonen B.V. Röntgenweg 1 2624 BD Delft Declare under our sole responsibility that the product Type: CM 11 / 14 Name: Pyranometer To which this declaration relates is in conformity with the following standards Imissions EN 50082-1... -
Page 4: Table Of Contents
1.2.3 Directional error..................11 1.2.4 Temperature dependence ..............11 TECHNICAL DATA ................13 Specifications ..................13 2.1.1 Technical data of single version CM 11..........13 2.1.2 Technical data of albedo version CM 14 ..........15 Accuracy....................18 INSTALLATION..................21 Delivery ....................21 Mechanical installation................ - Page 5 TABLE OF CONTENTS CALIBRATION ...................37 Initial calibration..................37 Recalibration ................... 37 Calibration procedure at Kipp & Zonen ..........39 6.3.1 The facility ....................39 6.3.2 Procedure....................39 6.3.3 Calculation....................40 6.3.4 Zero offset ....................40 6.3.5 Traceability to World Radiometric Reference......... 41 FREQUENTLY ASKED QUESTIONS (FAQ’S) ........43 TROUBLE SHOOTING...............45 PART NUMBERS / SPARE PARTS / OPTIONS........47...
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Page 6: General Information
In the inverted position reflected solar radiation can be measured. The albedometer CM 14 is based on two CM 11 sensors and is suitable for the measurement of net global radiation and/or albedo over surfaces of different nature (see chapter 5 for installation). -
Page 7: Physical Principles
Construction details (See figure 1) The sensing element of the pyranometer CM 11 is a black painted ceramic (Al ) disk. 100 thermocouples forming a thermopile are imprinted on it using thick film techniques. -
Page 8: Zero Offsets
(connected to the heat sink) and the hot junctions due to the heat flow necessary to load or unload the sensor heat capacity. In the CM 11 there is principally no zero offset B because there is a second non-illuminated compensation element. - Page 9 . This negative zero offset is also present on a clear day, however, hidden in the solar radiation signal. Figure 1 Approximate construction of Kipp & Zonen pyranometer CM 11. During indoor measurements with a solar simulator, the inner dome can become warmer than the pyranometer body due to net thermal radiation from the lamp housing.
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Page 10: Spectral Range And Spectral Selectivity
A. Using the CV 2 zero offset type A will be less than 7 W/m SUMMARIZED: Zero offset is the result of lack of thermal equilibrium in the instrument. Upper values of zero offset in CM 11 Zero offset A: 7 W/m response to 200 W/m... - Page 11 GENERAL INFORMATION Figure 2 Spectral reflectance of Carbon black coating as measured in a UV/VIS/NIR spectrophotometer with integrating sphere attachment.
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Page 12: Directional Error
GENERAL INFORMATION Figure 3 1. Relative spectral transmittance of two pyranometer domes. (Four surface reflections and index change with wavelength are taken into account). 2. Spectral distribution of solar radiation at sea level. Sun at zenith (Airmass 1). 1.2.3 Directional error The directional response is an individual feature and depends on imperfections of the glass domes and angular reflection properties of the black paint. - Page 13 GENERAL INFORMATION...
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Page 14: Technical Data
TECHNICAL DATA TECHNICAL DATA SPECIFICATIONS 2.1.1 Technical data of single version CM 11 Performance Spectral range: 310-2800 nm (50% points) 340-2200 nm (95% points) Sensitivity: between 4 and 6 µV/Wm Impedance: 700 -1500 Ohm Response time: < 15 s (95% response) <... - Page 15 TECHNICAL DATA Irradiance: 0 - 1400 W/m (max. 4000 W/m Non-stability: < 0.5% sensitivity change per year ± 2% (0,35 µm to 1,5 µm) Spectral selectivity Construction Receiver paint: Carbon black Glass domes: Schott N-K5 optical glass 2 mm thick, 30 mm and 50 mm outer diameter Desiccant: Silica gel...
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Page 16: Technical Data Of Albedo Version Cm 14
TECHNICAL DATA 2.1.2 Technical data of albedo version CM 14 • The general technical data of the CM 11 pyranometer also apply to the albedometer CM 14 • Sensors of equal sensitivity • Conical lower screen, which prevents illumination of the lower... - Page 17 TECHNICAL DATA Figure 5 Kipp & Zonen pyranometer CM 11 outline dimensions in mm.
- Page 18 TECHNICAL DATA Figure 6 Kipp & Zonen albedometer CM 14 outline dimensions in mm.
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Page 19: Accuracy
This is especially convenient in connection with a programmable data acquisition system. For the CM 11 the effect of each parameter on the sensitivity can be shown separately, because the parameters show less interaction. The non-linearity error, the sensitivity variation with irradiance, is... - Page 20 CM 11. The temperature dependence of the sensitivity is an individual function. For a given CM 11 the curve is somewhere in the shaded region of figure 8. Figure 8 The curve of relative sensitivity variation with instrument temperature of a pyranometer CM 11 is in the shaded region.
- Page 21 TECHNICAL DATA Relative directional error (Max zenith error in any azimuth direction) 8.00 4.00 6.00 4.00 2.00 2.00 0.00 0.00 -2.00 -2.00 -4.00 -6.00 -4.00 -8.00 Zenith angle [Degrees] Figure 9 Relative directional error...
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Page 22: Installation
In this case, and also if the contents are incomplete, your dealer should be notified in order to facilitate the repair or replacement of the instrument. The CM 11 pyranometer delivery will include the following items: CM 11 pyranometer White sun screen... -
Page 23: Mechanical Installation
(for example, by masts or exhaust pipes). Note that hot (over 100 degrees centigrade) exhausted gas will produce radiation in the spectral range of the CM 11 Pyranometer. The pyranometer should be distant from light-coloured walls or other objects likely to reflect sunlight onto it. - Page 24 INSTALLATION The World Meteorological Organisation recommends that the emerging leads are pointed to the nearest pole, to minimise heating of the electrical connections. However, if a polar diagram of the combined azimuth and cosine response is available, the pyranometer may be orientated so that the solar path lies in the low error region.
- Page 25 INSTALLATION Screw M5x80 Nylon insulator Washer M5 Nut M5 Figure 10 Mounting the pyranometer.
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Page 26: Installation For Measurement Of Solar Radiation On Inclined Surfaces
For easy levelling first use the screw nearest to the spirit level. When the CM 11 is placed horizontally using the spirit level, or when it is mounted with its base on a horizontal plane, the thermopile is horizontal within 0.05°. -
Page 27: Installation For Measurement Of Reflected Global Radiation
INSTALLATION 3.2.3 Installation for measurement of reflected global radiation In the inverted position the pyranometer measures reflected global radiation. According to the WMO the height should be 1-2 m above a surface covered by short cut grass. The mounting device should not interfere too much with the field of view of the instrument. -
Page 28: Installation For Measurement Of Diffuse Radiation
More information about the combination of CM 11 and tracker is given in the 2AP tracker manual. Figure 12 2AP tracker with pyranometer Alternatively the use of a shadow ring is possible, however less accurate. The shadow ring intercepts the direct solar radiation some days without readjustment, but also a proportion of the diffuse sky radiation. -
Page 29: Underwater Use
R 3.2.6 Underwater use The CM 11 pyranometer is in principle watertight. However, the hemispherical air-cavity under the dome(s) acts as a negative lens. The parallel beam of direct solar radiation becomes divergent after the passage of the outer dome. -
Page 30: Electrical Connection
INSTALLATION ELECTRICAL CONNECTION The CM 11 is provided with a 10 m cable with three leads and a shield covered with a black sleeve. The colour code is: plus blue minus white case The shield is isolated from the case, so no shield-current can exist. Shield and white lead may be connected to the same ground at the readout equipment. - Page 31 However, recorders with a variable voltage range can be set so that the result can be read directly in W/m Figure 14 Circuit diagram of the CM 11 pyranometer and connection to readout equipment. When an optional temperature sensor is built in, the following colour code is...
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Page 32: Electrical Connection Cm 14
INSTALLATION A considerable input bias current of the readout equipment can produce a voltage of several microvolts across the impedance of the pyranometer. The correct measured zero signal can be verified with a resistance replacing the pyranometer impedance at the input terminals. The pyranometer can also be connected to a computer or data acquisition system. - Page 33 INSTALLATION With the sensors connected in anti-series, the net global radiation is measured. When the outputs are recorded separately, the albedo can be calculated by dividing reflected by global radiation. Figure 15 Circuit diagram of Kipp & Zonen albedometer CM 14 and connection to readout equipment...
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Page 34: Operation
OPERATION OPERATION After completing the installation the pyranometer will be ready for operation. The irradiance value (E ) can be simply computed by dividing the output ↓ Solar signal (U ) of the pyranometer by its sensitivity (S ) formula 1, or by ensitivity multiplication of the voltage value with the reciprocal of the sensitivity. - Page 35 OPERATION...
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Page 36: Maintenance
MAINTENANCE MAINTENANCE Once installed the pyranometer needs little maintenance. The outer dome must be cleaned and inspected regularly, e.g. every morning. On clear windless nights the outer dome temperature of horizontally placed pyranometers will decrease, even to the dew point temperature of the air, due to IR radiation exchange with the cold sky. - Page 37 MAINTENANCE applies enough force. It is normal that you have to use two hands to open and close it. It is very difficult to make the pyranometers hermetically sealed. The only way to do this properly is to put the inside of the instrument under pressure. (> 1.0 Bar), but this has to be checked at yearly intervals.
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Page 38: Calibration
CALIBRATION CALIBRATION INITIAL CALIBRATION The ideal pyranometer should always have a constant ratio of voltage output to irradiance level (outside the instrument in the plane of the sensing element). This ratio is called sensitivity (S ) or responsivity. ensitivity The sensitivity figure of a particular pyranometer is unique. It is determined in the manufacturer's laboratory by comparison against a standard pyranometer. - Page 39 CALIBRATION Reference (maintained at Davos, Switzerland) embodied by several absolute pyrheliometers (black body cavity type). The comparisons are in-doors or at one of the regional Radiation Centres, see Appendix III. These institutes sometimes offer calibration facilities. There are several procedures for transferring calibration from a narrow field of view instrument (pyrheliometer) to a wide field of view instrument (pyranometer).
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Page 40: Calibration Procedure At Kipp & Zonen
CALIBRATION A summary of calibration methods is also found in the WMO guide of 1996. To send a pyranometer back for recalibration the use of the recalibration form in appendix V is strongly recommended. CALIBRATION PROCEDURE AT KIPP & ZONEN 6.3.1 The facility The indoor calibration procedure is based on a side-by-side comparison with a reference pyranometer under an artificial sun fed by an AC voltage stabiliser. -
Page 41: Calculation
CALIBRATION The problem of the zero offset is described below. This zero offset has to be subtracted to obtain the response due to illumination. So we get response A and B respectively. The irradiance at position 1 (pyranometer 'a') may be slightly different from that at position 2 (pyranometer 'b') due to asymmetry in the lamp optics etc. -
Page 42: Traceability To World Radiometric Reference
CALIBRATION A zero offset was also embodied in the response due to illumination. To correct for this unwanted response, the zero offset read after 60 s shading is subtracted. 6.3.5 Traceability to World Radiometric Reference Working standard pyranometers are maintained at Kipp & Zonen. Each standard pyranometer is characterised. - Page 43 CALIBRATION...
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Page 44: Frequently Asked Questions (Faq's)
FREQUNTLY ASKED QUESTIONS FREQUENTLY ASKED QUESTIONS (FAQ’s) The most frequently asked questions are listed below. For an update refer to the Kipp & Zonen web page: http://www.kippzonen.com Negative output during nighttime measurements? This error is related to the zero offset type A. Normally this zero offset is present when the inner dome has a different temperature from the cold junctions of the sensor. - Page 45 FREQUNTLY ASKED QUESTIONS Good ventilation of domes and body is the solution to reducing zero offsets even further. Kipp & Zonen advises the CV 2 for optimal ventilation and suppression of zero offset type A. Using the CV 2 zero offset type A will be less than 3 W/m Maximum and minimum irradiation quantities? Due to possible reflection from clouds the global irradiance at sea level can...
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Page 46: Trouble Shooting
TROUBLE SHOOTING TROUBLE SHOOTING The following contains a procedure for checking the instrument in case it appears that it does not function as it should. Trouble shooting: Output signal fails or shows improbable results: Check the wires, whether they are proper connected to the readout equipment. - Page 47 TROUBLE SHOOTING...
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Page 48: Part Numbers / Spare Parts / Options
Part no. Measuring/compensating cell in housing covered by inner glass dome 0305-161 Outer glass dome Ø 50 mm with metal ring 0305-162 Rubber ring for outer glass dome of CM 11 2132-426 Screen (plastic) 0305-166 Lower screen (CM 14) 0012-053... - Page 49 PART NUMBERS / SPARE PARTS / OPTIONS Description Part no. Mounting plate for 4 unventilated sensors (2 upper and 2 lower) 0012 092...
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Page 50: Appendix Iclassification According To Wmo Guide 1996
APPENDIX I APPENDIX I CLASSIFICATION ACCORDING TO WMO GUIDE 1996 High Good Moderat Characteristics CM 11 quality quality e quality Secondary Second ISO 9060 classification First class standard class Response time (95 percent response) 12 s < 15 s < 30 s <... - Page 51 APPENDIX I...
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Page 52: Appendix Ii Radiometric Levelling
APPENDIX II APPENDIX II RADIOMETRIC LEVELLING This must be done in the laboratory by mounting the instrument on a stand that can be rotated around an axis that is accurately vertical and passes through the centre of the receiving surface. The instrument then is illuminated by a lamp so that radiation falls at an elevation of approximately 15°... - Page 53 APPENDIX II...
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Page 54: Appendix Iii List Of World And Regional Radiation Centres53
APPENDIX IV APPENDIX III LIST OF WORLD AND REGIONAL RADIATION CENTRES World Radiation Centres Davos (Switzerland) St. Petersburg (Russia) Regional Radiation Centres Region I Africa: Cairo (Egypt) Khartoum (Sudan) Kinshasa (Zaire) Lagos (Nigeria) Tamanrasset (Algeria) Tunis (Tunisia) Region II Asia: Poona (India) Tokyo (Japan) Region III... - Page 55 APPENDIX IV...
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Page 56: Appendix Iv Recalibration Service
APPENDIX IV APPENDIX IV RECALIBRATION SERVICE Pyranometers, UV-meters, Pyrgeometers & Sunshine duration sensors Kipp & Zonen solar radiation measurement instruments comply with the most demanding international standards. In order to maintain the specified performance of these instruments, Kipp & Zonen recommends calibration of their instruments at least every two years. - Page 57 APPENDIX IV...
- Page 58 APPENDIX IV NAME COMPANY/INSTITUTE ADDRESS POSTCODE +CITY COUNTRY PHONE I would like to receive a price list for recalibration I would like to submit my instruments for recalibration Type/Model: Qty: Requested delivery time I intend to send the instruments to Kipp &...
- Page 59 APPENDIX IV...
- Page 60 APPENDIX IV NAME COMPANY/INSTITUTE ADDRESS POSTCODE +CITY COUNTRY PHONE I would like to receive a price list for recalibration I would like to submit my instruments for recalibration Type/Model: Qty: Requested delivery time I intend to send the instruments to Kipp &...
- Page 61 APPENDIX IV...
- Page 62 APPENDIX IV NAME COMPANY/INSTITUTE ADDRESS POSTCODE +CITY COUNTRY PHONE I would like to receive a price list for recalibration I would like to submit my instruments for recalibration Type/Model: Qty: Requested delivery time I intend to send the instruments to Kipp &...
- Page 63 APPENDIX IV...
- Page 64 C ustomer S upport Our customer support Für Servicearbeiten und Notre service 'Support Clientèle' remains at your disposal Kalibrierung, Verbrauchs- reste à votre entière disposition for any maintenance or material und Ersatzteile pour tout problème de repair, calibration, steht Ihnen unsere maintenance, réparation ou supplies and spares.