OTT HydroMet KIPP & ZONEN SMP12 User manual

Confidential - Company Proprietary
Instruction Manual
SMP12 • Smart Pyranometer

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Important user information
Dear customer, thank you for purchasing a Kipp & Zonen instrument. It is essential that you read this manual completely
for a full understanding of the proper and safe installation, use, maintenance and operation of your new SMP12 Smart
pyranometer.
We understand that no instruction manual is perfect, so should you have any comments regarding this manual we will
be pleased to receive them at:
OTT HydroMet B.V.
Delftechpark 36, 2628 XH Delft, - or
P.O. Box 507, 2600 AM Delft,
The Netherlands
[phone]
[email protected]
www.kippzonen.com
Warranty and Liability
OTT HydroMet B.V. guarantees that the product delivered under the Kipp & Zonen brand name has been thoroughly
tested to ensure that it meets its published specifications. The warranty included in the conditions of delivery is valid
only if the product has been installed and used according to the instructions supplied by OTT HydroMet B.V.
OTT HydroMet B.V. shall in no event be liable for incidental or consequential damages, including without limitation, lost
profits, loss of income, loss of business opportunities, loss of use and other related exposures, however incurred, rising
from the faulty and incorrect use of the product.
Modifications made by the user may affect the instrument performance, void the warranty, or affect the validity of the
CE declaration or other approvals and compliances to applicable International Standards.
Copyright © 2022 OTT HydroMet B.V.
All rights are reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any
form or by any means, without authorization by OTT HydroMet B.V.
OTT HydroMet B.V. reserves the right to make changes to this manual, brochures, specifications and other product
documentation without prior notice.
Manual Document Number: V2201-01
Publication date: January-2022

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Table of Contents
Contents
Important user information..............................................................................................................................................2
Introduction ......................................................................................................................................................................6
Safety precautions.................................................................................................................................................6
Waste disposal- WEEE directive 2012/19/EU.........................................................................................................6
Product overview ..............................................................................................................................................................7
The SMP12 pyranometer .......................................................................................................................................7
Included with the product.....................................................................................................................................8
Intended use ..........................................................................................................................................................8
International Standards ........................................................................................................................................8
Operation, measurement and background......................................................................................................................9
Data collection.......................................................................................................................................................9
Remote management............................................................................................................................................9
Key parts of the SMP12 pyranometer..................................................................................................................10
Dome...............................................................................................................................................................10
Diffuser............................................................................................................................................................10
Thermopile......................................................................................................................................................10
Housing ...........................................................................................................................................................11
Desiccant.........................................................................................................................................................11
Cable and connector.......................................................................................................................................11
Specifications..................................................................................................................................................................12
Optical and electrical...........................................................................................................................................12
Dimensions and weight .......................................................................................................................................13
Planning the installation of the SMP12 ..........................................................................................................................14
Where to place SMP12 in the PV plant ................................................................................................................14
Installation ......................................................................................................................................................................15
Tools required......................................................................................................................................................15
Pre-check .............................................................................................................................................................16
Pre-installation ....................................................................................................................................................16
Connecting in the office.......................................................................................................................................16
Changing the settings of the SMP12....................................................................................................................18
Finding the COM port for the USB-RS-485 converter.....................................................................................18
First start up....................................................................................................................................................18
Configuring the settings .................................................................................................................................19
Main Window –Setup .....................................................................................................................................19
Main window –Configuration and changes to it............................................................................................20
Finding a SMP12 with unknown communication parameters ......................................................................21
Proper installation for measurement of global horizontal irradiance (GHI)......................................................24

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Location ..........................................................................................................................................................24
Mounting.........................................................................................................................................................24
Horizontal orientation ....................................................................................................................................25
Horizontal levelling of the instrument ...........................................................................................................25
Fitting the connector and cable .....................................................................................................................26
Fitting the sun shield ......................................................................................................................................26
Installation for measurement of tilted (POA) global irradiance.........................................................................27
Tilted installation of the instrument ..............................................................................................................28
Fitting the connector and cable .....................................................................................................................29
Fitting the sun shield ......................................................................................................................................29
Installation for measurement of reflected global irradiance .............................................................................30
Installation for measurement of albedo .............................................................................................................31
Installation for measurement of diffused horizontal irradiance (DHI)...............................................................31
Electrical connections.....................................................................................................................................................32
Power connection................................................................................................................................................33
Power consumption ............................................................................................................................................33
Allowed power supply voltages with cable losses in mind............................................................................34
Connecting to a RS-485 network.........................................................................................................................35
Recommended cable types.................................................................................................................................36
SMP12 EMC and Surge protection details...........................................................................................................36
Maintenance and re-calibration .....................................................................................................................................37
Recommended weekly maintenance..................................................................................................................37
Recommended monthly maintenance ...............................................................................................................37
Recommended yearly maintenance ...................................................................................................................37
Calibration –Recommended every 2 years.........................................................................................................37
Calibration traceability to the WRR................................................................................................................37
Trouble shooting ......................................................................................................................................................38
Output signal not present or incorrect ...............................................................................................................38
Accessories ...............................................................................................................................................................39
Diffuse radiation measurement ..........................................................................................................................39
Mountings ............................................................................................................................................................39
Glare screen kit ....................................................................................................................................................39
Cables...................................................................................................................................................................39
Frequently Asked Questions ....................................................................................................................................40
Customer support.....................................................................................................................................................42
Appendices ...............................................................................................................................................................43
Modbus®...............................................................................................................................................................43
Commonly used Modbus® commands................................................................................................................43
Commonly used input registers ..........................................................................................................................44
Input register details ...........................................................................................................................................45

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Read-write Holding registers...............................................................................................................................46
Holding register details .......................................................................................................................................46
Copyright notices.................................................................................................................................................48
Using this table
Click on any item in the table of contents to be taken directly to the relevant page.
Click on the bottom of any page to be taken back to the table of contents.

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Introduction
Reading this entire manual is recommended for a full understanding of this product.
CAUTION
The triangle with exclamation mark is intended to alert the user to the presence of important installation,
operating and maintenance instructions in the literature accompanying the instrument.
WARNING Low voltage electrical equipment
This low voltage electrical equipment should only be installed and serviced by authorized personnel, meaning
people who have been trained and designated as “authorized” by their employers.
Note : Useful information for the user
Safety precautions
Do not use this equipment for measurements other than the rated measurement category.
Many hazards are associated with installing and maintaining instruments on towers or elevated structures. It is advised
to use qualified personnel for installation and maintenance. The client is responsible for following the local safety
regulations. The use of appropriate equipment and safety practices is mandatory. Check your company's safety procedure
and protective equipment prior to performing any work. If the SMP12 is mounted at a high position, special care must be
taken to secure both the person installing it and the instrument from falling during installation.
The manufacturer is not responsible for any damages due to misapplication or misuse of this product including, without
limitation, direct, incidental and consequential damages, and disclaims such damages to the full extent permitted under
applicable law. The user is solely responsible to identify critical application risks and install appropriate mechanisms to
protect processes during a possible equipment malfunction.
CAUTION Risk of burns due to hot surface at high ambient temperature
The metal parts of the SMP12 housing can become very hot at high ambient temperatures.
This can result in burns.
Wear appropriate gloves during installation and maintenance.
While every attempt is made to get the highest degree of safety in our products, the client assumes all risk from injuries
resulting from improper installation, use or maintenance of the SMP12.
Waste disposal- WEEE directive 2012/19/EU
The pictogram showing a waste bin with a cross means that the product is subject to European Union
regulations covering segregated waste disposal. Thisapplies both to the product itself and to anyaccessories
marked with the same symbol. Disposal of any such item as unsorted domestic waste is not allowed.

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Product overview
This manual, together with the instruction sheet, and the Smart Explorer manual, provides information related to the
installation, maintenance, calibration, product specifications and applications of the SMP12 pyranometer. If any
questions should remain, please contact your local OTT HydroMet 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 or software.
The SMP12 pyranometer
The SMP12 is a high quality pyranometer designed for measuring solar irradiance on a plane surface (radiant flux,
W/m²), which results from combination of the direct solar radiation and the diffuse sky radiation. The measurement can
be made horizontally for Global Horizontal Irradiance (GHI) or tilted for Global Tilted Irradiance (GTI).
The SMP12 can also be used to create an albedometer to measure surface reflectance where one SMP12 is facing the
ground and another SMP12 is facing the sky.
The SMP12 features:
•A diffuser based thermopile solar measurement sensor, fully compliant with ISO 9060:2018 Fast Response
Spectrally Flat Class A and with IEC 61724-1: 2021 for Class A PV plant monitoring
•Integrated dome heating with no moving parts to prevent dew and frost
•Enhanced surge protection on the data and power lines
•Remote tilt sensor to monitor the correct installation angle
•Internal relative humidity measurement to check the proper functioning of the internal desiccant
•Industry standard RS-485 Modbus® RTU communication
Internal digital signal processing and interfaces are optimised for industrial data acquisition and control systems. Kipp &
Zonen has developed a smart interface that features RS-485 Modbus® data communication for connection to
programmable logic controllers (PLC’s), inverters, digital control equipment and the latest generation of data loggers
and SCADA systems.
To achieve the required spectral and directional characteristics, the SMP12 uses a diffuser, optical filter, thermopile
detector and high quality glass dome. The SMP12 has a built-in bubble level and adjustable levelling feet. The snap-on
sun shield reduces solar heating of the housing.
The pyranometers are typically delivered with a waterproof plug pre-wired to a high quality signal cable, typically this is
10m long but other lengths are available. The instruments can also be ordered without a cable or with a plug only, for
the user to fit their own cable.

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Included with the product
The following items are included with the SMP12 pyranometer:
1SMP12 Smart Pyranometer
2Sun shield
3Optional cable 10, 25, 50, 100m pre-wired with 8-pins connector and connector-only available for customer to build
their own cable
4ISO 9060:2018 compliant calibration, directional response and temperature dependency certificate
5Instruction sheet
6Smart pyranometer fixing kit; 2 each of stainless steel M5 x 80 mm screw, nut, flat washer, nylon insulation rings.
Intended use
The SMP12 instrument is designed to measure and report solar irradiance, sensor body temperature, internal humidity
and tilt angle from horizontal.
The SMP12 can be mounted on a pole, cross-arm, or next to PV modules in a PV plant.
Communication is via Modbus® RTU using RS485 2-wire and the power supply needed is 10 to 30 VDC.
International Standards
The SMP12 is fully compliant with the requirements of ISO 9060:2018 for a Class A spectrally flat Pyranometer.
Spectrally Flat is the standard for Performance
Ratio input as it records all wavelengths reaching
the earth, from sunrise to sunset. Including the
spectrum valuable to PV modules.
The SMP12 complies with IEC 61724-1:2021
“Photovoltaic system performance –Part 1:
Monitoring” Class A instruments as it does not
need external heating and ventilation to prevent
morning dew and frost.
The SMP12 pyranometer is 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.
2
4
2x
2x
2x
2x
6
5
3
1

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Operation, measurement and background
.
The SMP12 only requires a suitable source of power and radiation (light) to operate and make measurements. However,
it is necessary to connect them to some sort of readout or data storage device in order to save the measurements, as there
is no internal data memory.
Data collection
An often used setting for the solar irradiation data interval is to sample every second and store one minute averages. For
setting up the combination of pyranometer and data storage please refer to the manual of your data collection device.
Remote management
Since the SMP12 offers extra data from the standard measurements and error registers we recommend to read and log
the following registers:
•Instrument body temperature: A temperature between 5 and 15 °C higher than ambient, depending on local weather
conditions like wind, indicates a properly functioning heating system.
•Instrument tilt angle: For a fixed pyranometer (GHI or POA) any short term change >1° from the value recorded just
after installation, would require attention. The higher threshold helps to eliminate any influence of e.g. strong winds
or mounting material expansion and contraction due to temperature changes
For long term management an average is suitable and any change >0.2° would require attention.
•Instrument internal relative humidity (RH%): Since the internal volume is small and RH% is very much temperature
and desiccant dependent, the value will fluctuate over the day and that is no reason for alarm.
It is advised to measure the RH% over longer periods of time (months-years) during the cooler part of the day, above
freezing point and when possible at roughly the same reported body temperature (e.g. around midnight).

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Key parts of the SMP12 pyranometer
The detector of the SMP12 is based on a passive thermal sensing element called a thermopile. Although the detector
construction differs between models, the fundamental working principle is applicable to all SMP pyranometers.
The thermopile responds to the total incoming energy through the diffuser, which is non-spectrally selective. The
thermopile warms up and the heat generated flows through a thermal resistance to a heat-sink, the pyranometer housing.
The temperature difference across the thermal resistance of the detector is converted into a small voltage as a linear
function of the absorbed irradiance.
The rise of temperature in the thermopile is easily affected by wind, rain and thermal radiation losses to the environment
(for example, a ‘cold’ sky). Therefore the detector of the SMP12 is shielded by a dome. The dome allows equal
transmittance of the direct solar component for every position of the sun in the hemisphere above the detector.
The SMP12 has a sealed construction with a non-customer-replaceable internal desiccant. The internal desiccant lasts for
10 years and as standard is replaced during recalibration.
Dome
The material of the pyranometer dome defines the spectral measurement range of the instrument. In general 97 to 98 %
of the solar radiation spectrum will be transmitted through the dome and will be scattered by the diffuser. The solar
irradiance can come from any direction within the hemisphere above the pyranometer and therefore the domes are
designed to minimize errors in measurement at all incident angles (the directional response).
Diffuser
The diffuser is an optical element that scatters and transmits light from all directions. It is designed in such a way so that
the instrument has a nearly ideal cosine response.
Thermopile
The thermopile sensing element is made up of a large number of very small thermocouple junction pairs connected
electrically in series. The absorption of thermal radiation by one of the thermocouple junctions, called the active (or ‘hot’)
junction, increases its temperature. The differential temperature between the active junction and a reference (‘cold’)
junction kept at a fixed temperature produces a voltage directly proportional to the differential temperature created.
This is a thermoelectric effect. The sensitivity of a pyranometer depends on the individual physical properties of the
thermopile and its construction. The sensitivity of each thermopile is unique and therefore each pyranometer has an
individual calibration factor. This sensitivity is stored in the SMP pyranometer configuration memory