Hukseflux SR05, SR05-D1A3-PV User Manual

USER MANUAL

SR05-D1A3-PV

Digital second class pyranometer – alternative for PV reference cell

Hukseflux

Thermal Sensors

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Warning statements

Putting more than 30 Volt across the sensor wiring of the main power supply can lead t o permanent damage to the sensor.

Keep the voltage on the RS-485 data wiring of SR05-D1A3-PV between -7 and +12 V to avoid permanent damage.

For proper instrument grounding: use SR05 with its original factory-made SR05 cable.

Using the same Modbus address for more than one device will lead to irregular behaviour of the entire network.

Disconnect power whi le performing service or maintenance.

Locally connect the cable shield to ground if SR05-D1A3-PV is not connected to ground throu gh the installation platform.

Modbus

is a registered trademark of Schneider Electric, licens e d to the Modb us Organization, Inc.

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Contents

Warning statements 2 Contents 3 List of symbols 5 Introduction 6 1 Ordering and checking at delivery 11

1.1 Ordering SR05-D1A3-PV 11

1.2 Included items 13

1.3 Quick instrument check 14

2 Instrument principle and theory 15 3 Specifications of SR05-D1A3-PV 18

3.1 Specifications of SR05-D1A3-PV 18

3.2 Dimensions of SR05 22

4 Standards and recommended practices for use 23

4.1 Classification standard 23

4.2 General use for solar radiation measurement 23

4.3 General use for sunshine duration measurement 23

4.4 Specific use for outdoor PV system perfo rmance testing 24

4.5 Specific use in meteorology and climatology 25

5 Installation of SR05 26

5.1 Site selection and installation 26

5.2 Mounting and levelling SR05 27

5.3 Installing SR05 27

5.4 Installing SR05 with its ball levelling and tube mount 28

5.5 Placing and removing SR05’s ball levelling shim 30

5.6 Electrical connection of SR05-D1A3-PV: wiring diagram 32

5.7 Grounding and use of t he shield 32

5.8 Using SR05-D1A3-PV’s digital output 33

5.9 Using SR05-D1A3-PV’s analogue 0 to 1 V output 36

6 Communication with SR05 37

6.1 PC communication: Sensor Manager software 37

6.2 Network communication: function codes, registers, coils 43

6.3 Silicon Reference Cell compatible Modbus output 45

6.4 Standard Hukseflux Modbus Output 48

6.5 Network communication: getting started 53

6.6 Network communication: example master reques t to SR05 54

7 Making a dependable measurement 56

7.1 The concept of dependability 56

7.2 Reliability of the measurement 57

7.3 Speed of repair and maintenance 58

7.4 Uncertainty evaluation 58

8 Maintenance and trouble shooting 61

8.1 Recommended maintenance and quality assurance 61

8.2 Trouble shooting 62

8.3 Calibration and che cks in the field 63

8.4 Data quality assurance 64

9 Appendices 66

9.1 Appendix on cable extension / replacement 66

9.2 Appendix on tools for SR05 68

9.3 Appendix on spare parts for SR05 68

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9.4 Appendix on standards for classification and calibration 69

9.5 Appendix on calibration hierarchy 70

9.6 Appendix on meteorological radiation quantities 71

9.7 Appendix on ISO and WMO classification tables 72

9.8 Appendix on definition of pyranometer specifications 73

9.9 Appendix on terminology / glossary 74

9.10 Appendix on floating point format conversion 75

9.11 Appendix on function codes, register and co il overview 76

9.12 Appendix on the sensor model name in the register 80

9.13 EU declaration of conformity 81

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List of sy m bols

Quantities Symbol Unit Voltage output U V

Sensitivity S V/(W/m

)

Solar irradiance E W/m

Output of 0-1 V U V Transmitted range of 0-1 V r W/m

(see also appendix 9.6 on meteorological qua ntities)

Subscripts

Not applicable

Notation Example

Decimal numbers are indicated without prefix 30 Hexadecimal numbers are indicated with a 0x prefix 0x1E

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Introduction

SR05 series is the most affordable range of pyranometers meeting ISO 9060 requirements. These sensors are ideal for general solar radiation measurements and popular for monitoring photovoltaic (PV) systems. Model SR05-D1A3–PV is made as a perfect alternative to PV reference cells. It offers the same Modbus interface as the most common PV reference cell model for easy compatibility. Relative to PV reference cells, SR05-D1A3-PV has the advantage of higher stability, independence of the PV cell type or anti-reflection coating, and better availability and price of recalibration.

SR05 series is an economical range of ISO 9060 second class pyranometers for measurement of solar radiation received by a plane surface, in W/m

, from a 180 ° field of view angle. SR05 is perfect for predicting generated power and monitoring the overall efficiency of PV power plants. Different mounting options are available, allowing SR05 to be mounted in virtually any situation. The combination of easy installation and its low cost makes SR05 the preferred solution for commercial scale PV systems.

There are several versions of SR05 series:

• Version SR05-D1A3: digit al s e nsor wit h Mo db us ove r RS-485 and analogue 0-1 V output

• Version SR05-D2A2: digit al s e nsor wit h Mo db us ove r TTL and ana log ue 4–20 mA output

• Version SR05-A1: analogue senso r w it h an a log u e m ill iv olt output

and:

•

Version SR05-D1A3-PV: d igit al se nso r w ith M odb us o ver RS-485, alternative for PV

reference cell

This user manual covers use of SR05-D1A3-PV. Specifications of this version differ from those of the other digital and analogue sensors in the SR05 series range. For use of SR05-D1A3 or SR05-D2A2, consult the separate SR05-D1A3 & SR05-D2A2 user manual. For use of SR05-A1, offering analogue millivolt output, consult the separate SR05-A1 user manual.

Figure 0.1 SR05-D1A3-PV digital second class pyranometer seen from above

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Model SR05-D1A3-PV has a digital output that is identical to the most commonly used photovoltaic reference cell with Modbus over RS-485 output. This allows for easy installation in existing PV monitoring systems, without the need to make major modifications to data logging software, instrument libraries and infrastructure.

Compared to silicon reference cells, pyranometers offer several advantages such as a perfect (cosine) directional response and a flat spectral response over a wide range. Pyranometers therefore meas ure the maximum available resource and are suitable to act as a reference for all types (for example amorphous, crystalline or thin-film) of photovoltaic cells both with and without anti-reflection coating. See also our Application note “pyranometers versus PV reference cells”. Moreover, since the working principle of a pyranometer is different from a solar cell, the pyranometer offers a truly independent measurement of the irradiance.

PV system performance monitoring: compliant with IEC 61724-1, Class C

IEC 61724-1: Photovoltaic System Performance Monitoring - Guidelines for Measurement, Data Exchange and Analysis – suggests to use pyranometers for PV monitoring; SR05 complies with IEC 61724-1 class C system requirements.

Features and benefits of SR05-D1A3-PV

• higher stability than PV reference cells

• indepen den t of P V ce ll typ e

• affordable calibration

• register structure and content identical to most common reference cells for easy

exchangeability

• easy imple me nta tio n an d ser vic ing

• easy mou n tin g a n d le v e llin g

• pricing: affordable second class pyranometers

Figure 0.2 Two SR05-D1A3-PV digital second class pyranometers, of which one measuring in Plane of Array, replacing PV reference cells

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SR05-D1A3-PV design

SR05 pyranometers employ a thermopile sensor with black coated surface, one dome and an anodised aluminium body with visible bubble level. Optionally the sensor can be delivered with a unique ball levelling mechanism and tube mount or dedicated mounting fixture, for easy installation. SR05-D1A3-PV has an industry standard digital output: Modbus RTU over half-duplex RS-485, that allows multiple sensors to be installed on a single network. In addition, SR05-D1A3-PV has analogue 0 to 1 V output.

Figure 0.3 On the left SR05-D1A3-PV pyranometer with bubble level and M12-A cable connector in its standard configuration (3 metre ca ble standard included); on the right SR05 with optional ball levelling, for easy mounting and levelling on (non-)horizontal surfaces (included mounting bolts not displayed)

Figure 0.4 SR05-D1A3-PV digital second class pyranometer with optional ball levelling and tube mount for easy mounting and levelling on a tube (tube not included)

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Communication with a PC: Hukseflux Sensor Manager Software

For communication between a PC and SR05-D1A3-PV(‘s), the Hukseflux Sensor Manager software can be used. It is available for download on our website. The software allows the user to quickly configure SR05-D1A3-PV Modbus address and serial communication settings (baud rate, parity and stopbits) and to plot and export data. Also, the digital outputs may be viewed for sensor diagnostics.

Figure 0.5 U

ser

interface of the Hukseflux Sensor Manager

Compatibility

SR05-D1A3-PV’s Modbus interface is exchangeable with IMT-Solar Si-RS485TC-T-MB PV reference cell’s interface. Other reference cells upon request.

Suggested use for SR05-D1A3-PV

• replacement of PV reference cells

• measuring global tilted irradiance (GTI) in the Plane of Array (PoA) of solar panels

• measuring global horizontal irradiance (GHI)

SR05-D1A3-PV is suited for use in SCADA (Supervisory Control And Data Acquisition) systems, supporting Modbus RTU (Remote Terminal Unit) protocol over RS-485. In these networks the sensor operates as a slave. Using SR05-D1A3-PV in a network is easy. Once it has the correct Modbus address and communication settings and is connected to a power supply, the instrument can be used in RS-485 networks. A typical network wil l request the irradiance (either register 0x0000 or registers 0x1002 + 0x1003) and temperature data (either register 0x0007 or register 0x1006) every 1 second, and eventually store the averages every 60 seconds. How to issue a request, process the register content and convert it to useful data is described in the paragraphs about network communication. The user should have sound knowledge of the Mo db us communication protocol when installing sensors in a network. When using the analogue 0 to 1 V output provided by SR05-D1A3-PV, the instrument can be connected directly to commonly used datalogging systems capable of handling a 0 to 1 V signal.

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The recommended calibration interval of pyranometers is 2 years. The registers containing the applied sensitivity and the ca libra tion history of the digital versions of SR05 are accessible for users with a password. This allows the user to choose his own local calibration service. The same register access may also be used for remotely controlled re-calibration of pyranometers in the field. Ask Hukseflux for information on this feature and on ISO and ASTM standardised procedures for field calibration.

The ASTM E2848 “Standard Test Method for Reporting Photo voltaic Non-Concentrator System Performance” (issued end 2011) confirms that a pyr anometer is the preferred instrument for PV system performance monitoring. SR05 pyranometer complies with the requirements of this standard. For more information, see our pyranometer selection

guide.

WMO has approved the “pyranometric method” to calculate sunshine duration from pyranometer measurements in WMO-No. 8, Guide to Meteorological Instruments and Methods of Observation. This implies that SR05 may be use d, in combination with appropriate software, to estimate sunshine duration. This is much more cost-effective than using a dedicated sunshine duration sensor. Ask for our application note.

All SR05 versions should be used in accordance with the recommended practices of ISO, WMO and ASTM.

See also

• view our comp lete range of sensors

• PMF01 pyranometer mounting fixture, compatible with SR05 ball levelling

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1 Ordering and checking at delivery

1.1 Ordering SR05-D1A3-PV

SR05-D1A3-PV second class pyranometer has a digital output that is identical to the most commonly used photovoltaic reference cell with Modbus over RS-485 output.

Besides SR05-D1A3-PV, SR05 series offers several other versions with industry standard outputs, both digital and analogue. Each version offers multiple mounting options and various cable lengths:

• SR05-D1A3 digital second class sensor, with Modbus over RS-485 and 0-1 V output

• SR05-D2A2 digital second class sensor, with Modbus over TTL and 4-20 mA output

• SR05-A1 analogue second class pyranometer with millivolt output

This is our standard Modbus model which is not directly exchangeable with the commonly used PV reference cells.

For an overview of all versions and options, and how to order, please take a look at Table

1.1.1 on the next page.

The standard configuration of SR05-D1A3-PV is with 3 metres cable length. Common options for SR05-D1A3-PV are:

• longer cable (10, 20 metres). Specify total cable length

• extension cable with connector pair (10, 20 metres). Specify total cable length

• with ball levelling (-BL)

• with ball levelling and tube mount (for tube diameters 25 to 40 mm, -TMBL)

Ball levelling and tube m ount are suited for retrofitting.

SR05-D1A3-PV’s Modbus interface is exchangeable with IMT-Solar Si-RS485TC-T-MB PV reference cell’s interface. Other reference cells upon request.

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Table 1.1.1 Ordering codes for the versions of model SR05

VERSIONS OF SR05 (part numbers), without cable

SR05-D1A3-PV

digital second class pyranometer, with Modbus ove r

RS-485 output, alternative for PV reference cell

SR05-D1A3-PV-BL

digital second class pyranometer, with Modbus ove r RS-485 output, alternative for PV reference cell, with ball

levelling

SR05-D1A3-PV-TMBL

digital second class pyranometer, with Modbus ove r RS-485 output, alternative for PV reference cell, with tube

mount on ball levelling

SR05-D1A3

digital second class pyranometer, with Modbus ove r

RS-485 and 0-1 V output

SR05-D1A3-BL

digital second class pyranometer, with Modbus ove r RS-485 and 0-1 V output, with ball levelling

SR05-D1A3-TMBL

digital second class pyranometer, with Modbus ove r

RS-485 and 0-1 V output, with tube mount on ball

levelling

SR05-D2A2

digital second class pyranometer, with Modbus ove r TTL and 4-20 mA output

SR05-D2A2-BL

digital second class pyranometer, with Modbus over TTL

and 4-20 mA output, with ball levelling

SR05-D2A2-TMBL

digital second class pyranometer, with Modbus ove r TTL

and 4-20 mA output, with tube mount on ball levelling

SR05-A1

analogue second class pyranometer, with millivolt output

SR05-A1-BL

analogue second class pyranometer, with millivolt output,

with bal l le v elling

SR05-A1-TMBL

analogue second class pyranometer, with millivolt output, with tube mount on ball levelling

CABLE FOR SR05, with female M12-A connector at sensor end, non-stripped on other end

‘-03’ after SR05 part number

standard cable length: 3 m

‘-10’ after SR05 part number

cable length: 10 m

‘-20’ after SR05 part number

cable length: 20 m

CABLE EXTENSION FOR SR05, with male and female M12-A connectors

C06E-10

cable length: 10 m

C06E-20

cable length: 20 m

An extension cable (wit h connector pair) can be used in combination w ith a regular cable (with one connector at sensor end) to make alternative SR0 5 cable lengths possible.

Example: Cable length needed: 15 m. In this case, it is eas iest to buy SR05 with a 20 m cable and to cut it to desired length.

Example: Cable length needed: 30 m. In this case, it is eas iest to buy SR05 with 10 m cable and a cable extension of 20 m.

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1.2 Included items

Arriving at the customer, the delivery should include:

• pyranometer SR05-D1A3-PV

• cable of the length as ordered

• product certificate matching the instrument serial number

For SR05-D1A3-PV-BL, also

• ball levelling

• 4 mm hex key

• 1 x shim

• 2 x M5x20 bolts

• 2 x M5 nuts

For SR05-D1A3-PV-TMBL, also

• ball levelling

• 4 mm hex key

• 1 x shim

• 2 x M5x20 bolts

• 2 x M5 nuts

• tube mount

• 2 x M5x30 bolts

• 2 x M5x40 bolts

Please store the certificate in a safe place. The Hukseflux Sensor Manager can be downloaded via www.hukseflux.com/downloads

SR05-D1A3-PV SR05-D1A3-PV-BL SR05-D1A3-PV-TMBL

Figure 1.2.1 From left to right: SR05-D1A3-PV, SR05-D1A3-PV-BL and SR05-D1A3-PV-

TMBL (nuts and bolts, tools and certificates are not shown, tube itself is not included)

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1.3 Quick instrument check

A quick test of the instrument can be done by connecting it to a PC and installing the Sensor Manager software. See the chapters on installation and PC communication for directions.

1. At power–up the signal may have a temporary output level different from zero; an offset. Let this offset settle down.

2. Check if the sensor reacts to light: expose the se nso r to a strong light source, for instance a 100 W light bulb at 0.1 m distance. The signal should read > 100 W/m

now. Darken the sensor either by putting something over it or switching off the light. The instrument irradiance output should go down and within one minute approach 0 W/m

3. Inspect the bubble level.

4. Inspect the instrument for any damage.

5. Check the instrument serial number as indicated by the software against the label on the instrument and against the certificates provided with the instrument.

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2 Instrument principle and theory

Figure 2.1 Overview of SR05: shaded areas in exploded view show ball levelling mount and shim

(1) cable (standard length 3 metres, optional longer cable) (2) connector (3) bubble level (4) thermal sensor with black coating (5) glass dome (6) sensor body (7) tube mount (optional) (8) mounting screw (included with ball levelling and tube mount; requires 4 mm hex key) (9) shim (included with and needed for ball levelling mount) (10) ball levelling mount (optional) (11) countersunk set screw for levelling adjustment (included with ball levelling mount;

requires 4 mm hex key)

(12) opening for Ø 25 to Ø 40 mm tube when using ball levelling and tube mount

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SR05’s scientific name is pyranometer. A pyranometer measures the solar radiation received by a plane surface from a 180 ° field of view angle. This quantity, expressed in W/m

, is called “hemispherical” solar radiation. The solar radiation spectrum extends

roughly from 285 to 3000 x 10

-9

m. By definition a pyranometer should cover that

spectral range with a spectral selectivity that is as “flat” as possible.

In an irradiance measurement by definition the response to “beam” radiation varies with the cosine of the angle of incidence; i.e. it should have full response when the solar radiation hits the sensor perpendicularly (normal to the surface, sun at zenith, 0 ° angle of incidence), zero response when the sun is at the horizon (90 ° angle of incidence, 90 ° zenith angle), and 50 % of full response at 60 ° angle of incidence. A pyranometer should have a so-called “directional response” (older documents mention “cosine response”) that is as close as possible to the ideal cosine characteristic.

In order to attain the proper directional and spectral characteristics, a pyranometer’s main components are:

• a thermal sensor with black coating. It has a flat sp ectrum covering the 200 to 50000

x 10

-9

m range, and has a near-perfect directional response. The coating absorbs all solar radiation and, at the moment of absorption, converts it to heat. The heat flows through the sensor to the sensor body. The thermopile sensor generates a voltage output signal that is proportional to the solar irradiance.

• a glass dome. This dome limits the spectral range from 285 to 3000 x 10

-9

m (cutting

off the part above 3000 x 10

-9

m), while preserving the 180 ° field of v iew angle. Another function of the dome is that it shields the thermopile sensor from the environment (conve ction, rain).

• The digital versions of model SR05 have a high-end 24-bit A/D converter, which is used by SR05 to convert the analogue thermopile voltage to a digital signal. SR05D1A3-PV has a digital output that is identical to the most commonly used photovoltaic reference cell with Modbus over RS-485 output for easy exchangeability.

Pyranometers can be manufactured to different specifications and with different levels of verification and characterisation during production. T he ISO 9060 - 1990 standard, “Solar energy - specification and classification of instruments for measuring hemispherical solar and direct solar radiation”, distinguishes b etween 3 classes; secondary standard (highest accuracy), first class (second highest accuracy) and second class (third highest accuracy).

From second class to first class and from first class to secondary standard, the achievable accuracy improves by a factor 2.

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Figure 2.2 Spectral response of the pyranometer compared to the solar spectrum. The pyranometer only cuts off a negligible part of the total solar spectrum.

0,2

0,4

0,6

0,8

1,2

100 1000 10000

relative spectral conten t /

response [arbitrary units]

wavelength [x 10

-9

solar radiation

pyranometer

response

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3 Specifications of SR05-D1A3-PV

3.1 Specifications of SR05-D1A3-PV

SR05 pyranometers measure the solar radiation received by a plane surface from a 180 ° field o f view angle . This quantity, expressed in W/m

, is called “hemispherical” solar

radiation.

SR05-D1A3-PV offers irradiance in W/m

as a digital output and as a 0-1 V output. It must be used in combination with suitable power supply and a data acquisition system which uses the Modbus communication protocol over RS-485 or one that is capable of handling a 0-1 V signal.

The instrument is classified according to ISO 9060 and should be used in accordance with the recommended practices of ISO, IEC, WMO and ASTM.

Table 3.1.1 Specificat ions of SR05-D1A3-PV (continued on next pages)

SR05-D1A3-PV MEASUREMENT SPECIFICATIONS: LIST OF CLASSIFICATION CRITERIA OF ISO 9060*

ISO classification (ISO 9060: 1990)

second class pyranometer

WMO performance level (WM O -No. 8,

seventh edition 2008)

moderate quality pyr a nometer

Response time (95 %)

18 s

Zero offset a (response to 200 W/m2

net thermal radiat ion)

< 15 W/m2 unventilated

Zero offset b (response to 5 K/h

change in ambient temperature)

< ± 4 W/m2

Non-stability

< ± 1 % change per year

Non-linearity

< ± 1 % (100 to 1000 W/m2)

Directional resp onse

< ± 25 W/m2

Spectral selectivity

< ± 5 % (0.35 to 1.5 x 10

-6

Temperature response

< ± 3 % (-10 to +40 °C)

Tilt response

< ± 2 % (0 to 90 ° at 1000 W/m2)

*For the exact definition of pyranometer ISO 9060 specifications see the appendix.

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Table 3.1.1 Specifications of SR05-D1A3-PV (continued)

SR05-D1A3-PV

ADDITIONAL SPECIFICATIONS

Measurand global irradiance

(hemispherical solar radiation)

Measurand in SI r a diometry units

irradiance in W/m2

Optional measurand

sunshine duration

Field of view angle

180 °

Measurement range

0 to 2000 W/m2

Spectral range

(20 % transmission p oints)

285 to 3000 x 10-9 m

Rated operating temperatu r e r a nge

-40 to +80 °C

Output definition running average over 4 last meas urements,

measurement every 0.1 s

Recommended data reques t in terval

1 s, storing 60 s averages

Measurement function / optional

programming for sunshine duration

programming according to W M O guide paragraph

8.2.2

Measurand

instrument body temperat ure

Temperature sensor

Solid state System on Chip (SoC) silicon bandgap temperature sensor

measurand in SI units

temperature in °C

Standard governing use of the

instrument

ISO/TR 9901:1990 Solar en er gy -- Field pyranometers

-- Recommended practice for u s e ASTM G183 - 05 Standa r d P r a c tice for Field Use of

Pyranometers, Pyrheliometers and UV Radiometer s

Standard cable length (see options)

3 m

Cable diameter

4.8 x 10-3 m

Cable conductor cross-section

0.25 x 10-6 m2 (24 AWG)

Chassis connector

M12-A straight male connector, male thread, 5-pole

Cable connector

M12-A straight female connector, female thread, 5pole

Connector protec tion class

IP67

Cable replacement

replacement and extension c a bles with connector(s) can be ordered separately from Hukseflux

Mounting (see opti ons)

2 x M5 bolt at 46 mm centre-to-centre distance on north-south axis, r equires 4 mm hex key

Levelling (see op tions)

bubble level is included

Levelling accuracy

< 0.6 ° bubble entirely in ring

Desiccant

silica gel, 1.0 g, in a HDPE bag, (25 x 45) mm

IP protection cla s s

IP67

Gross weight including 3 m cable

0.45 kg excluding optional a c c es s or ies

Net weight including 3 m cable

0.35 kg excluding optional a c c es s or ies

Packaging

box of (170 x 100 x 80) mm

CALIBRATION

Calibration trace a b ility

to WRR

Calibration hierarchy from WRR through ISO 9846 and ISO 9847, applying

a correction to ref er e nce conditions

Calibration method

indoor calibration according to ISO 9847, Type IIc

Calibration un certainty

< 1.8 % (k = 2)

Recommended recalibrati on interval

2 years

Reference conditions

20 °C, normal incide nce solar radiation, horizonta l mounting, irradiance level 1000 W/m2

Validity of calibra tion

based on experience the ins trument sensitivity will not change during storage. Durin g use under exposure to solar radiation th e instrument “non-stability” specification is applicable.

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Table 3.1.1 Specifications of SR05-D1A3-PV (started on previous pages)

MEASUREMENT ACCURACY AND RESOLUTION

Uncertainty of the measurement statements about the overall measurement

uncertainty ca n only be made on an individual basis.

see the chapter on uncertainty evaluation

WMO estimate on achievable accuracy for daily sums (see appendix for a

definition of the measurement conditions)

10 %

WMO estimate on achievable accuracy

for hourly sums (see appendix for a definition of the measurement conditions)

20 %

Irradiance resolution 0.1 W/m2 (register address 0x0000)

0.01 W/m2 (register address 0x1002 + 0x1003)

Instrument body temperature resolution 0.1 °C (register address 0x0007)

0.01 °C (register address 0x 1006)

Instrument body temperat ure accuracy

± 0.5 °C

SR05-D1A3-PV

Rated operating voltage ra nge

5 to 30 VDC

Recommended operating voltage

12 VDC

Power consumption

< 48 x 10-3 W at 12 VDC

SR05-D1A3-PV: DIGITAL

Digital output irradiance in W/m2

instrument body temperat ure in °C

Communication pr otocol

Modbus over 2-wire RS-485

Transmission mode

RTU

RS-485 transceiver common mode range

-7 to +12 V

RS-485 transceiver type

2-wire, non-isolated

System requirements for us e with PC Windows 7 and later, USB or RS-232 (COM) port and

connector, RS-485 / USB converter or RS-485 / RS-

232 converter

Software requirements for use with PC

Java Runtime Environment 8 – latest version available

free of charge at http://www.java.com, Hukseflux Sensor Manager - software version v1817 or higher

User interface on PC Hukseflux Sensor Man a ger v1817 or higher software

downloadable: to download and for available software updates, see

http://www.hukseflux.com/page/downloads

SR05-D1A3-PV: ANALOGUE 0 TO 1 V

0 to 1 V output

irradiance in W/m2

Transmitted range

0 to 1600 W/m2

Output signal

0 to 1 V

Standard setting (see options) 0 V at 0 W/m2 and

1 V at 1600 W/m

OPTIONS

Longer cable: 10,20 m

Cable with M12-A female c onnector on

sensor end, non-stripped on other end

option code = total cable length

Extension cable with connector pair: 10, 20 m. Cable with male and fem a le M12-A connectors

option code = C06E-10 for 10 metres, C06E-20 for 20 metres

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Table 3.1.1 Specifications of SR05-D1A3-PV (started on previous pages)

Ball levelling mountab le on (non-)horizontal surfaces

with angle compens ation up to 10 °; retrofittable; one shim, two M5x20 mounting bolts and two M5 nuts included; requires 4 mm hex k ey for levelling and 4 mm hex key and 8 mm wrench for mounting

option code = BL

Tube mount with b a ll le velling

mountable on tubes Ø 25 to Ø 40 mm

with angle compen s ation up to 10 °; retrofittable; one shim, two M5x 3 0 a nd two M5x40 mounting bolts included; requires 4 m hex key for levelling and mounting

option code = TMB L

Alternative pyranometer mounting

fixture

for mounting an y H ukseflux pyranometer on

horizontal and v er tical tubes, on platforms, both horizontal and in Plane of Array order code = PMF01

PMF01 is compatible with SR05 ball levelling

Adapted transmitted range 0 to 1 V

can be adjusted at the factory upon request

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3.2 Dimensions of SR05

Figure 3.2.1 Dimensions of SR05 in x 10

-3

m. The bottom drawing shows the height of SR05 combined with its optional ball levelling mount and the tube diameter required for use with SR05’s optional tube mount. M5 mounting bolts and the countersu nk set screw require a 4 mm hex key for mounting and levelling.

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4 Standards and recommended practices

for use

Pyranometers are classified according to the ISO 9060 standard and the WMO-No. 8 Guide. In any application the instrument should be used in accordance with the recommended practices of ISO, IEC, WMO and / or ASTM.

4.1 Classification standard

Table 4.1.1 Standards for pyranometer classification. See the appendix for definitions of

pyranometer specifications, and a table listing the specification limits.

STANDARDS FOR INSTRUMENT CLASSIFICATION

ISO STANDARD EQUIVALENT

ASTM STANDARD

WMO

ISO 9060:1990 Solar energy -- specification and classification of instruments for measuring hemispherical solar and direct solar radiation

Not available

WMO-No. 8; Guide to Meteorological Instruments and Methods of Observation, chapter 7, measurement of radiation, 7.3 measurement of global and diff use solar radiation

4.2 General use for solar radiation measurement

Table 4.2.1 Standards with recommendations for instrument use in solar radiation

measurement

STANDARDS FOR INSTRUMENT USE FOR HEMISPHERICAL SOLAR RADIATION

ISO STANDARD

EQUIVALENT

ASTM STANDARD

WMO

ISO/TR 9901:1990 Solar energy -- Field pyranometers -- Recommended practice for use

ASTM G183 - 05 Standard Practice for Field Use of Pyranometers, Pyrheliometers and UV Radiometers

WMO-No. 8; Guide to Meteorological Instruments and Methods of Observation, chapter 7, measurement of radiation, 7.3 measurement of global and diff use solar radiation

4.3 General use for sunshine duration measurement

According to the World Meteorological Organization (WMO, 2003), sunshine duration during a given period is defined as the sum of that sub-period for which the direct solar irradiance exceeds 120 W/m

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WMO has approved the “pyranometric method” to estimate sunshine duration from pyranometer measurements (Chapter 8 of the WMO Guide to Instruments and Observation, 2008). This implies that a pyranometer may be used, in combination with appropriate software, to estimate sunshine duration. Ask for our application note.

Table 4.3.1 Standards with recommendations for instrument use in sunshine duration measurement

STANDARDS FOR INSTRUMENT USE FOR SUNSHINE DURATION

WMO

WMO-No. 8; Guide to Meteorological Instruments and Methods of Observation, chapter 8, measurement of s unshine duration, 8.2.2 Pyranometric Method

4.4 Specific use for outdoor PV system performance testing

Pyranometers are used for monitoring PV power plant efficiency, in order to measure incoming solar radiation independently from the PV system. Pyranometers can be placed in two positions:

• plane of array (POA), parallel to the PV panels, for measurement of the in-plane

irradiance (also noted as G

i in IEC 61724-1)

• horizontally, for measurement of the global horizontal irradiance (E, also noted as GHI in IEC 61724-1)

SR05 series is applicable in outdoor PV system performance testing. See also Huks eflux model SR15-D1 “digital first class pyranometer” and SR30-D1 “digital secondary standard pyranometer”.

Table 4.4.1 Standards with recommendations for i n strument use in PV system performance testing

STANDARDS ON PV SYSTEM PERFORMANCE TESTING

IEC / ISO STANDARD

EQUIVALENT ASTM STANDARD

IEC 61724-1; Photovoltaic system performance monitoring – guidelines for measurement, data exchange and analysis

COMMENT: Allows pyranometers or reference cells according to IEC 60904-2 and -6. Pyranometer reading requi r ed a c c uracy better than 5% of reading (Par 4.1)

COMMENT: equals JISC 8906 (Ja pa nese Industrial Standards Committee)

ASTM 2848-11; Standard Test M ethod for Reporting Photovoltaic Non-Concentrator System Performance

COMMENT: confirms that a pyranometer is the preferred instrument for outdoor PV testing. Specifically recommends a “first class” pyranometer (paragraph A 1. 2.1.)

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4.5 Specific use in meteorology and climatology

The World Meteoro logical Org anization (W MO) is a specialised agency of the United Nations. It is the UN system's authoritative voice on the state and behaviour of the earth's atmosphere and climate. WMO publishes WMO-No. 8; Guide to Meteorological Instruments and Met hod s of Observation, in which a table is included on “level of performance” of pyranometers. Nowadays WMO conforms itself to the ISO classification system.

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Hukseflux SR05, SR05-D1A3-PV User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual