Delta-T SPN1 User Manual Download Page 1

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User Manual for the

Sunshine

Pyranometer

type

SPN1

SPN1-UM-1.0

Delta-T Devices Ltd

Summary of Contents for SPN1

Page 1: ...User Manual for the Sunshine Pyranometer type SPN1 SPN1 UM 1 0 Delta T Devices Ltd ...

Page 2: ... acknowledged Some names referred to are registered trademarks CE Conformity The SPN1 Sunshine Pyranometer conforms to EU regulations regarding electromagnetic emissions and susceptibility and is CE marked by Delta T Devices Ltd Warnings To maintain conformance to CE standards the equipment must be used as described in this manual Modifications to the equipment may invalidate CE certifications Del...

Page 3: ...s 21 SPN1 spectral response 23 SPN1 cosine response 24 Routine maintenance 25 Calibration procedure and traceability 27 Warranty and service 29 Terms and conditions of sale 29 Service and spares 30 Technical support 30 Problems 31 Troubleshooting 31 Appendix A Design and test summary 32 Introduction 32 Design objectives 32 How the design evolved 32 Calculation of outputs 33 Test results 34 Appendi...

Page 4: ...ne sensor with three output channels 1 Total global solar radiation 2 Diffuse radiation 3 Sunshine status The SPN1 measures short wave radiation between 400nm and 2700nm in W m 2 The Direct beam component of solar radiation can be calculated from the Total minus the Diffuse component The Sunshine status output indicates whether the energy in the direct beam exceeds the WMO standard threshold value...

Page 5: ...re and manuals CD contains SunRead Windows PC software that will read the SPN1 output values and status information via the PC RS232 serial port SunRead also provides a basic logging capability while the SPN1 is connected to the PC Use with data logger The three outputs of the SPN1 can be logged with a suitable data logger The Total and Diffuse radiation millivolt outputs require two analogue chan...

Page 6: ...indicator and a red light emitting diode LED The LED flashes when the SPN1 is taking readings There are two external connectors a 5 pin RS232 connector for serial communications and an 8 pin connector for analogue signals and power The serial port is provided for checking real time readings using the SunRead software or for attachment to digital data collection systems See also Appendix B RS232 co...

Page 7: ...x 10 mm holes at 120 on 108 mm dia circle 120 54mm radius Three M8 x 12 mm bolts Levelling thumbwheel Tripod mount 3 8 inch BSW thread Three 8 mm holes at 120 on 60 mm dia circle Three 8 mm slots at 120 on 60 mm dia circle Bolt down using slot and opposing hole M8 x 10 mm threaded hole for support arm SPN1 ARM SPN1 BP Levelling baseplate 125 mm dia x 10 mm Support arm SPN1 ARM includes levelling j...

Page 8: ...System overview 8 z Introduction SPN1 User Manual v1 0 ...

Page 9: ... PC to a GP1 logger see the GP1 DL6 Network Quick Start Guide on the Delta T Software and Manuals CD Power considerations The SPN1 is a powered sensor There are three possible sources of power 1 Power from the data logger This only needs to be applied when the logger takes a reading The SPN1 s Total Diffuse and Sun outputs on the analogue output connector are valid 100ms after power is applied and...

Page 10: ... at 15V Above 0 C the power reduces smoothly to 20 at 5 C and then down to nothing at 33 C Heater control 0 10 20 30 40 50 60 70 80 90 100 10 5 0 5 10 15 20 25 30 35 4 Temp degC Heater Current 0 At zero wind speed the dome will remain snow and ice free down to minus 20 C At 2m s 1 wind speed the dome will remain snow and ice free down to minus 10 C In air temperatures below freezing the heater can...

Page 11: ...tal Diffuse and Sun outputs are active 100ms after a voltage is applied to the DL Power cable and are updated every 100ms The Total and Diffuse outputs have a range of 0V 2 5V 0V 1 3V in normal daylight conditions with an internal resistance of 100Ω There is also some protection on these outputs if they are taken outside their normal range These outputs should be measured by a high impedance volta...

Page 12: ...ding details The Total and Diffuse outputs are protected from electrostatic discharge ESD by the transient voltage suppressors TZ4 6 and from low voltage misconnection by the zener clamps D7 D8 and resettable fuses F3 F3 0 1A F4 0 1A SPN1 power supply R23 100R R12 100k R24 100R DAC TOTAL DAC DIFFUSE TR2 MTD3055VL GND C19 0 1uF C20 0 1uF F5 0 5A 60V Total Diffuse Sun TZ4 5V TZ5 5V TZ6 24V D7 3 0V D...

Page 13: ...5V or more to enable the analogue outputs The power required can be taken either from the DL Power line or the heater supply For most logging situations one of the following two connections is recommended 1 No heater SPN1 powered by logger warmup This connection would be appropriate for an isolated battery powered logger such as the Delta T GP1 The SPN1 heater is left disconnected The logger must ...

Page 14: ...le The SPN1 heater is powered up and the SPN1 analogue outputs are permanently enabled for logging V V Power supply 12 15V 1 5A Outputs isolated from mains CH1 CH1 CH2 CH2 PWR GND 5V Datalogger DIG DIG Analogue input Analogue input Digital input DL Gnd DL Power Htr Htr Screen Total Diffuse SigGND Sun 14 z Introduction SPN1 User Manual v1 0 ...

Page 15: ...logger is not supplying power for the SPN1 Otherwise power supply currents may flow through the SigGND cable which may cause voltage offsets on the Total and Diffuse readings with long cable lengths 2 Logger resistance input If the logger has no digital inputs but can measure resistance then the Sun output can be measured with a 10k resistor connected in parallel This will be measured as 10k with ...

Page 16: ...e a potential divider 4 Switching an external load If for any reason you want to use the Sun output to switch a high current load you should make sure that the current return path is through the DL Gnd wire and not the SigGND wire otherwise you may see large offset voltages on your Total and Diffuse readings CH1 CH1 PWR GND 5V Datalogger Analogue input 10k Voltage Sun SigGND DL Gnd 16 z Introducti...

Page 17: ...e cable type SPN1 w 05 is connected to the SPN1 enclosure internally creating a continuous screen around the sensor electronics and output connectors The screen is connected to the sensor ground by an 18V transient suppressor to minimise the possibility of high voltages relative to the internal circuitry if there are nearby lightning strikes In general the screen black wire should be connected to ...

Page 18: ...rvice release of Ls2Win you will need to reinstall the sensor library This is described in the online Ls2Win Release Notes installed with Ls2Win and which can be found from the Start menu under Programs Ls2Win Documents DL6 logger The DL6 logger is not suitable for use with the SPN1 The input voltage range is insufficient and we provide no SPN1 sensor types or program for it Warning Do not attempt...

Page 19: ...DTR line RX in 3 Blue 3 RS232 RX in to SPN1 SDI 12 4 Black Not used TX out 5 Grey 2 RS232 TX out of SPN1 The SPN1 uses the serial connector for reporting readings upgrading software and for factory setup and testing The SunRead software on the Delta T Software and Manuals CD can be used to give an immediate display of the SPN1 outputs and to give a very basic logging capability The SPN1 sensor not...

Page 20: ...e horizon Offsets Most thermopile pyranometers show a negative output during the night due to radiative cooling of the earth into space The construction of the SPN1 includes three separating elements between the atmosphere and the thermopiles so this effect is minimal The electronics within the SPN1 will only measure and output positive signals so the output should never go below zero In general t...

Page 21: ...ge 0 2500 mV Sunshine status threshold 120 W m 2 in the direct beam Other specifications Accuracy Sunshine status 10 sun hours with respect to the threshold Accuracy Cosine correction 2 of incoming radiation over 0 90 Zenith angle Accuracy Azimuth angle 5 over 360 rotation Temperature coefficient 0 02 per C typical Temperature range 20 to 70 C Stability Recalibration recommended every 2 years Resp...

Page 22: ...ects SPN1 to SPN1 RS232 cable or to another SPN1 RS 10 cable SPN1 BP Leveling base plate 125 mm dia 10 mm thick plate with 3 M5 x thumbscrews and 3 M8 x 25 mm stainless steel bolts See page 7 SPN1 ARM Support arm for SPN1 with leveling joint Length 1m dia 34 mm with adapter for attaching to 33 52 mm dia mast Supplied with instruction sheet See page 7 SPN1 SD Spare desiccant for SPN1 2 spare desicc...

Page 23: ...0 2500 3000 Wavelength nm relative contribution 0 0 05 0 1 0 15 0 2 0 25 0 3 0 35 0 4 Solar SPN1 This shows the spectral response of the Sunshine Pyranometer thermopile diffusers and dome combined shown with the solar spectrum at ground level SPN1 User Manual v1 0 Technical reference z 23 ...

Page 24: ...20 30 40 50 60 70 80 90 Zenith angle degrees Ideal cosine Absolute output Relative error 2 limits This graph shows the typical cosine response of the Sunshine Pyranometer compared to the ideal cosine curve The upper curve shows the relative accuracy 24 z Technical reference SPN1 User Manual v1 0 ...

Page 25: ... is indicated by a coloured panel under the dome The dessicant indicator plug has two more indicators Blue indicates dry pink indicates a humidity threshold has been exceeded Renew when either the 50 RH indicator or the upper indicator in the dome goes pink Check the desiccant indicators every 3 months In most conditions the desiccant should last over 6 months and usually for several years before ...

Page 26: ...0 If in doubt replace with a fresh canister Make sure no dust or moisture gets into the SPN1 while the plug is unscrewed Maintaining the dome Air pollution and residues in rain and snow can make the dome quite dirty A clean dome is essential to maintain the accuracy of the SPN1 The dome is made of borosilicate glass Clean it when necessary with a damp cloth moistened with mild detergent or isoprop...

Page 27: ...enly over the whole range of zenith angles After the shadow mask is fitted the SPN1 reading is checked again in the calibration lamp rig The transfer standard SPN1s are periodically checked outside over a period of several weeks and a range of climatic conditions against a solar tracker and shading disk system using two Kipp CM6B double dome reference pyranometers These references are calibrated a...

Page 28: ...28 z Technical reference SPN1 User Manual v1 0 ...

Page 29: ...e at Delta T s premises in the UK during the warranty period If Delta T requires that goods under warranty be returned to them from overseas for repair Delta T shall not be liable for the cost of carriage or for customs clearance in respect of such goods However we much prefer to have such returns discussed with us in advance and we may at our discretion waive these charges Delta T shall not be li...

Page 30: ...st repairs or recalibration additional delays of a few weeks may be expected Technical support Technical Support is available on Delta T products and systems Users in countries that have a Delta T Distributor or Technical Representative should contact them in the first instance Technical Support questions received by Delta T will be handled by our Tech Support team Your initial enquiry will be ack...

Page 31: ...l will flash when the SPN1 is taking readings If using the RS232 cable check that you are using the correct cable and that it is plugged into the same serial port on your PC that you have selected in the SunRead software If logging check the logger cable and compare with your logger wiring connection diagram Make sure that the DL Power wire is connected to 5V to enable the analogue outputs Check a...

Page 32: ...th of these approaches require accurate alignment to the Earth s axis and regular adjustment Another well established approach is the Campbell Stokes recorder which uses a glass sphere to focus the Direct solar beam onto a recording chart causing a burn which indicates Direct beam strength Design objectives The aim of the SPN1 design was to measure the Direct and Diffuse components of incident sol...

Page 33: ...irect MAX MIN Total Direct Diffuse MAX MIN The Total and Diffuse values are used for the instrument output Note This analysis is independent of the spectral characteristics of the individual sensors or their spatial response Calculations SPN1 outputs Let MAX and MIN be the largest and smallest thermopile reading of the seven thermopiles after being adjusted for any calibration factors calibration ...

Page 34: ...values Test results SPN1 output 0 100 200 300 400 500 600 700 800 900 1000 0 5 0 0 0 6 0 0 0 7 0 0 0 8 0 0 0 9 0 0 1 0 0 0 1 1 0 0 1 2 0 0 1 3 0 0 1 4 0 0 1 5 0 0 1 6 0 0 1 7 0 0 1 8 0 0 1 9 0 0 27April 2006 Reading in W m 2 CM6Tot CM6Diff SPN1Tot SPN1Diff This graph shows a typical daily output from the SPN1 It is plotted against two Kipp CM6 pyranometers one shaded by a disk on a solar tracking ...

Page 35: ...0 700 800 900 1000 SPN1 Global W m 2 This graph shows SPN1 Total lower trace and Diffuse upper trace outputs compared with two Kipp CM6s and a solar tracking shade disk Data recorded at Winster Derbyshire between September and December 2004 The graph plots hourly averages of readings every 5 seconds Note the offset Y axis to separate the Total and Diffuse plots SPN1 User Manual v1 0 Appendix A Des...

Page 36: ...tals measured by a BF3 compared to the WMO definition of 120 W m 2 in the Direct beam Data recorded at Napier University Edinburgh between February and July 2001 Comparable data from an adjacent Campbell Stokes recorder is also plotted The SPN1 uses a very similar algorithm and will give comparable results 36 z Appendix A Design and test summary SPN1 User Manual v1 0 ...

Page 37: ...also via RS232 are in normal weight All RS232 input characters are echoed back except for the R command For commands with more than one input character a command is abandoned if the input is not within appropriate range or 1 minute after a key press Unrecognised and aborted commands return Sleep mode Processor is in its lowest power state If the sensor is asleep when the DL POWER pin goes high the...

Page 38: ...mmand CR and the TEST prompt will be echoed Any unrecognised character or incorrectly formatted input will return the sensor to Sleep mode This mode is designed for manufacturing and technical support purposes and is not intended to be accessed by the user or user software The format of these commands may change without maintaining backwards compatibility WARNING some of these commands can permane...

Page 39: ... Ext 5874 mV Vcc 3299 mV 2006 01 10 00 02 43 Reports temperature of PCB thermister and internal CPU temp can be very inaccurate Reports battery voltage not usually fitted on SPN1 external supply and regulated Vcc Also reports if DL POWER or HTR POWER inputs are active Reports date time reset on power up Nc nnnnn OK Sets user calibration factor for individual thermopile c to nnnnn 04096 represents ...

Page 40: ... date String 3 4 are Main thermopile PCB serial numbers Others as yet unused Yyyyy mm dd Date Hhh mm ss Time An0 An1 read ADCn Vcc Vref Bn read PD Cnnnn Calibrate CLEAR Set cal to 1 DEFAULT Restore default cal E cal values F Get DCO Freq G Set DCO to 1MHz I Status Info Nc nnnnn set cal c to nnnnn Onnnn nnnn set DACs Pn nx read set pin x is 01 Q Scan PDs R Reset to normal S Send data Tn nn Sunshine...

Page 41: ...rom scattering in the atmosphere or reflection from clouds Direct beam light coming directly from the sun with no scattering Usually treated as if it comes from a point source Energy radiation measured with equal sensitivity to the energy content regardless of wavelength It is measured in units of W m 2 The normal daylight maximum is a little over 1000 W m 2 Sunshine the threshold for bright sunsh...

Page 42: ...24 41 D data logger 5 analogue outputs 11 Desiccant 25 Design and Test Summary 32 Diffuse light 41 Direct 4 Direct beam 41 DL2e Logger 18 DL6 Logger 18 E Earthing 17 Energy 41 Environmental sealing 22 Error SPN1 not responding 31 Unexpected output readings 31 Errors offset 20 shadow mask 20 thermopile matching 20 EXT M12 x analogue extension cable 9 22 G Glossary 41 GP1 logger cabling 9 GP1 Logger...

Page 43: ...ing plate 7 SPN1 w 05 analogue cable 9 22 pin outs and wiring 11 SPN1 CAL calibration service 22 SPN1 RS 10 serial extension cable 9 SPN1 RS232 pin outs and wiring connections 19 serial cable 9 serial cable 22 SPN1 SD spare desiccant 22 SPN1 UM user manual 22 Stability 21 sun output 11 wiring connection options 15 SunRead 5 Sunshine 41 Sunshine status 4 Sunshine status threshold 21 SPN1 ARM 7 22 S...

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