OTT HydroMet KIPP & ZONEN SMP Series Quick start guide

an OTT HydroMet brand
SMP Series Smart Pyranometers
Operational Manual
0374212 | 01-1123

Copyright ©OTT HydroMet B.V.
OTT HydroMet B.V.
Delftechpark 36
2628 XH Delft
The Netherlands
+31152755210
[email protected]
www.otthydromet.com
All rights reserved.
All content is the intellectual property of OTT HydroMet. Reprinting, duplication
and translation (even as excerpts) are only permitted with the prior written
consent of OTT HydroMet.
Subject to technical change.

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Table of contents
1 Scope of supply 5
2 Order numbers and variant code 6
2.1 Product variants 6
2.2 Accessories and spare parts 6
3 About this manual 7
3.1 Other applicable documents 7
3.2 General signs and symbols 7
3.3 Explanation of warnings 7
4 General safety instructions 8
4.1 Intended use 8
4.2 Potential misuse 8
4.3 Personnel qualification 8
4.4 Personnel obligations 8
4.5 Danger of burns due to hot surfaces 8
4.6 Correct handling 8
4.7 Certification 9
5 Product description 10
5.1 Design and function 10
5.2 Product overview 11
6 Transport, storage, and unpacking 12
6.1 Unpacking 12
6.2 Storage 12
7 Installation 13
7.1 Planning installation 13
7.2 Mechanical installation 13
7.2.1 Preparatory work 13
7.2.2 Required tools and aids 13
7.2.3 Installation for measuring global radiation 13
7.2.4 Installation for measuring global radiation on sloping surfaces 15
7.2.5 Installation for measuring reflected radiation 16
7.2.6 Installation for measuring albedo 16
7.2.7 Installation for measuring diffuse radiation 17
7.3 Electrical installation 18
7.3.1 Electrical connections 18
7.3.2 Grounding pyranometer 18
7.3.3 Power connection 18

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7.3.4 Power consumption 18
7.3.5 Analog voltage output 19
7.3.6 Analog current output 19
7.3.7 Connecting to computer 20
8 Commissioning 21
8.1 Set up instrument 21
8.1.1 Starting the Smart Explorer Software 22
8.1.2 Establishing connections 23
8.1.3 Adjusting the communication parameters 24
8.1.4 Finding an instrument with unknown communication parameters 26
9 Operation 27
9.1 Making and saving measurements 27
9.2 Collecting data 27
10 Maintenance 28
10.1 Maintenance schedule 28
11 Troubleshooting 29
11.1 Fault elimination 29
12 Repair 30
12.1 Customer support 30
13 Notes on disposing of old devices 31
14 Technical data 32
14.1 Optical and electrical data 32
14.2 Dimensions and weight 35

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1 Scope of supply
The following items are included with SMP series pyranometers:
– Smart pyranometer
– Sun shield
– Optional cable, pre-wired with 8-pins connector or connector only for customer cable
– Calibration certificate
– Instruction sheet
– Pyranometer fixing kit SMP3:
– 2 stainless steel screws each: M5x30mm, M5X40mm and M5x50mm
– Nuts and flat washers
– Pyranometer fixing kit SMP6, SMP10 and SMP22:
– 2 stainless steel screws M5x80mm
– Nuts and flat washers
– Nylon insulation ring

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2 Order numbers and variant code
2.1 Product variants
Variant Order number
SMP3 0374900
SMP6 0374920
SMP10 0374905
SMP22 0374940
2.2 Accessories and spare parts
Accessories
Item Order number
CVF 4 Ventilation Unit 0378910
CMF1 - Albedometer mount 0362700
CMF4 - Albedometer mount 0362703
Unventilated glare screen kit 0305722
Ventilated glare screen kit 0305725
AMPBOX 0365900
METEON Data Logger 0365910
METEON 2.0 Data Logger 0388900
LogBoxSE Data Logger 3303096
Fixed Feet 0362705
CMP3 Albedometer Rod 0338720
CM121B/C Shadow Ring - Unventilated 0346900
CM121B/C Shadow Ring - Ventilated 0346901
Smart Powered Hub 0382440
Smart Hub 0382445
PMU485 Smart Set Hub 0382460
For SMP3, SMP6, SMP10, SMP22
Item Order number
Waterproof 8-pin plug 2523146
10m cable, pre-wired with waterproof 8-pin plug 0362621
25m cable, pre-wired with waterproof 8-pin plug 0362623
50m cable, pre-wired with waterproof 8-pin plug 0362624
100m cable, pre-wired with waterproof 8-pin plug 0362625

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3 About this manual
3.1 Other applicable documents
The following documents contain further information on installation, maintenance and calibration:
– Smart Pyranometer Communication Manual
– Smart Explorer Software Manual
3.2 General signs and symbols
The signs and symbols used in the operating manual have the following meaning:
Practical tip
iThis symbol indicates important and useful information.
Action
üPrerequisite that must be met before performing an action.
4Step 1
ðIntermediate result of an action
4Step 2
ðResult of a completed action
List
– List item, 1st level
– List item, 2nd level
3.3 Explanation of warnings
To avoid personal injury and material damage, you must observe the safety information and warnings in the
operating manual. The warnings use the following danger levels:
WARNING
WARNING
This indicates a potentially hazardous situation. If the hazardous situation is not avoided, it may result in death or
serious injuries.
CAUTION
CAUTION
This indicates a potentially hazardous situation. If the hazardous situation is not avoided, it may result in
moderately serious or minor injuries.
NOTICE
NOTE
This indicates a situation from which damage may arise. If the situation is not avoided, products may be damaged.

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4 General safety instructions
4.1 Intended use
The pyranometer is used to measure and report the solar radiation.
4.2 Potential misuse
Any use of the product that does not comply with the intended use, be this intentional or negligent, is forbidden by
the manufacturer.
4Use the product only as described in the operational manual.
4.3 Personnel qualification
The equipment described in this manual must be installed, operated, maintained and repaired by qualified
personnel only.
4Obtain training from OTT HydroMet if necessary.
4.4 Personnel obligations
To avoid equipment damage and injury when handling the product, personnel are obliged to the following:
4Read the operational manual carefully before using the product for the first time.
4Pay attention to all safety information and warnings.
4If you do not understand the information and procedure explanations in this manual, stop the action and
contact the service provider for assistance.
4Wear the necessary personal protective equipment.
4.5 Danger of burns due to hot surfaces
The metal parts of the housing may get very hot when subject to a high ambient temperature (>60°C). If someone
touches the housing, these metal parts may cause burns.
4Wear protective gloves during installation and maintenance.
4.6 Correct handling
If the product is not installed, used and maintained correctly, there is a risk of injury. The manufacturer does not
accept any liability for personal injury or material damage resulting from incorrect handling.
4Install and operate the product under the technical conditions described in the operational manual.
4Do not change or convert the product in any way.
4Do not perform any repairs yourself.
4Get OTT HydroMet to examine and repair any defects.
4Ensure that the product is correctly disposed of. Do not dispose of it in household waste.

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4.7 Certification
CE (EU)
The equipment meets the essential requirements of EMC Directive 2014/30/EU.
FCC (US)
FCC Part 15, Class "B" Limits
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received, including interference that may cause undesired operation.
IC (CA)
Canadian Radio Interference-Causing Equipment Regulation, ICES-003, "Class B"
This Class B digital apparatus meets all requirements of the Canadian Interference-Causing Equipment
Regulations.

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5 Product description
5.1 Design and function
The SMP series instruments are radiometers designed for measuring short-wave irradiance on a plane surface
(radiant flux, W/m2) which results from the sum of the direct solar radiation and the diffuse sky radiation incident
from the hemisphere above the instrument.
Two pyranometers can be used as albedometers. The upper measures incoming global solar radiation and the
lower measures solar radiation reflected from the surface below, when the two signal outputs have been converted
to irradiance in W/m3, the albedo can be simply calculated.
SMP pyranometers feature a 2-wire smart interface with RS-485 Modbus® (RTU) protocol for connection to
programmable logic controllers (PLC’s), inverters, digital control equipment and data loggers. All models are
available in two versions. One has an analog voltage output of 0 to 1V, the other has an analog current output of 4
to 20mA. Digital signal processing provides faster response times and, with an integrated temperature sensor,
corrects for the temperature dependence of the detector sensitivity.
To achieve the required spectral and directional characteristics SMP pyranometers use thermopile detectors and
glass domes. The thermopile responds to the total energy absorbed by black surface coating, which is spectrally
non-selective. The thermopile warms up and the heat generated flows through a thermal resistance to a heat-sink,
the pyranometer housing.
The rise of temperature in the thermopile is easily affected by wind, rain and thermal radiation losses to the
environment and the delicate black coating must be protected. Therefore the detector is shielded by one or two
domes. These domes allow equal transmittance of the direct solar radiation component for every position of the
sun in the hemisphere above the detector. The internal desiccant prevents condensation on the inner sides of the
domes, which can cool down considerably on clear windless nights.
The pyranometers have built-in bubble levels and adjustable leveling feet. Snap-on sun shields reduce solar
heating of the housings. The waterproof connectors have gold-plated contacts.
Albedometers are constructed using two pyranometers, an albedometer mounting rod, and a glare screen to
prevent direct sunlight from below the horizon entering the lower pyranometer.
The pyranometers are delivered with a waterproof plug pre-wired to a signal cable. The cable is 10m long but
other lengths are available. The instruments can also be ordered with a plug only, for the user to fit their own
cable.

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5.2 Product overview
1
2
3
4
5
6
8
9
7
1
2
3
4
5
678
9
SMP3 pyranometer
1 Sun shield 6 Adjustable leveling feet
2 Thermopile detector 7 Smart interface
3 Glass dome 8 Fixed foot
4 Connector 9 Housing
5 Bubble level
1
2
3
4
7
8
11
10 9
5
6
1
2
3
4
5
6
7
8
9
10
11
SMP6, SMP10, SMP22 pyranometers
1 Sun shield 7 Housing
2 Inner glass dome 8 Adjustable leveling feet
3 Outer glass dome 9 Smart interface
4 Thermopile detector 10 Fixed foot
5 Bubble level 11 Internal desiccant
6 Connector

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6 Transport, storage, and unpacking
6.1 Unpacking
4Carefully remove the product from the packaging.
4Check that the delivery is complete and undamaged.
4If you find any damage or if the delivery is incomplete, then immediately contact the supplier and
manufacturer.
4Keep the original packaging for any further transportation.
6.2 Storage
4Store within specified temperature ranges.
4Store in dry area.
4Store in original box where possible.

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7 Installation
7.1 Planning installation
For the solar irradiation to be measured in the entire photovoltaic system, it is necessary to position several
pyranometers in the system. The number of pyranometers required depends on the system’s performance and
ambient conditions.
The minimum number of sensors required for a Class A system is defined as follows:
– 1 sensor for each monitoring point to measure the following values:
– In-plane irradiance (POA)
– Global horizontal irradiance
– In addition, the following sensors are used:
– 1 horizontal albedo sensor
or
– 3 in-plane rear-side irradiance sensors
The number of monitoring points depends on the system size, as seen in the table below:
System size (AC) in MW Number of monitoring points Number of pyranometers
<40 2 6to10
≥40 to <100 3 9to15
≥100 to <300 4 12to20
≥300 to <500 5 15to25
≥500 to <700 6 18to30
≥700 7, plus 1 for every further 200MW 21+to35+
7.2 Mechanical installation
7.2.1 Preparatory work
4If using the digital output, then set the Modbus® address before visiting the site. Otherwise a computer and
RS-485 / USB converter is required during installation.
7.2.2 Required tools and aids
The following tools and aids are required:
– Allen key, 4mm
– wrench, 8mm
– open-ended wrench, 16mm or ⅝"
7.2.3 Installation for measuring global radiation
7.2.3.1 Choosing a site
There should be no obstructions to the field of vision above the instrument’s sensor element. If this is not possible,
the location of the instrument must be chosen to ensure that obstacles do not rise by more than 5degrees above
the azimuth range between sunrise after the shortest night and sunset on the longest day.

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The 5degrees correspond to a minimum distance from the instrument to the obstacle of 10times the height of the
obstacle:
h
>10 x h
Minimum distance from instrument to obstacle
The minimum distance is important for measuring the direct radiation. The diffuse solar radiation is not so affected
by obstacles near the horizon. An obstacle to the field of vision that rises 5degrees over the entire azimuth range
of 360degrees reduces the diffuse radiation directed downwards by only 0.8%.
4Position the instrument in such a way that no shadows fall on it, for instance from masts.
4Avoid hot exhaust gases with a temperature of over 100°C in the proximity of the instrument. The radiation
can cause measurement deviations.
4Do not position the instrument in front of light-colored walls or any other objects that reflect the sunlight or
emit short-wave radiation.
7.2.3.2 Mounting
65 mm
1
2
3
4
5
1 2x M5x80mm screws 4 2x flat washers
2 2x nylon insulating rings 5 2x nuts
3 2x Ø5.2mm
4To insulate the instrument against the temperature of the mounting device, place the instrument on the
adjustable foot and the two leveling feet.

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4Position the instrument in such a way that the nuts are located at a distance of 2 to 3mm from the mounting
device.
4Ensure that the instrument is grounded.
4Ensure that the instrument is not in the shade.
4When installed horizontally, point the cable connector towards the nearest pole to reduce the UV exposure on
the cable.
4In order to align the instrument horizontally, rotate the leveling feet until at least half the spirit level bubble is
in the inner ring.
4Fix the instrument with the screws, ensure that the instrument retains the correct alignment.
4To prevent corrosion between the screws and the instrument housing, ensure that the nylon insulating rings
are fixed.
4Insert the connector with the cable into the instrument’s connection socket.
4Tighten the locking ring hand tight.
NOTICE!The seal may be damaged by overtightening!
4Fix the cable in such a way that the cable doesn’t move or cast a shadow on the instrument.
4Fix the sun shield.
7.2.4 Installation for measuring global radiation on sloping surfaces
In a photovoltaic system, the pyranometer must be installed at the same zenith angle and azimuth angle as the
modules. The pyranometer can be mounted using the adjustable leveling feet or using a set of fixed feet that are
suitable for mounting on sloping surfaces.
2
1
1 Zenith angle ±1° 2 Azimuth angle ±2°
4Place the pyranometer on a horizontal surface.
4Ensure that the leveling feet protrude as far as the adjustable foot.
4Level the pyranometer.
4Label the pyranometer with a note stating that the feet have been set.
4Alternatively, remove the leveling feet and mount the fixed feet.
4Label the pyranometer with a note stating that the fixed feet are suitable for sloping installation.
4Fix the pyranometer on the sloping surface.
4Point the cable connector downwards to reduce moisture exposure around the connector.

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7.2.5 Installation for measuring reflected radiation
In inverted position the pyranometer measures the reflected global radiation.
R S
D
1
2
5
3
4
H
1 Mounting plate
2 Pyranometer
3 Glare screen
4 Mast
5 Equator
The mounting plate prevents the pyranometer from being heated by solar radiation. The optional glare screen has
an angle of 5degrees and prevents direct radiation on the glass dome during sunrise and sunset.
The mounting device must not excessively disrupt the pyranometer’s field of vision. The mast in the illustration
absorbs the radiation reflected by the earth’s surface with a fraction of D/2πS. In the worst case (sun at its zenith),
the pyranometer shadow reduces the signal by a factor of R2/H2. As a rule of thumb, a black shadow under the
pyranometer with a radius of 0.1xH reduces the signal by 1%. 99% of the signal comes from a range with a radius
of 10xH.
4Level the mounting plate well, as the pyranometer will be mounted without feet.
4Fix the pyranometer to the mounting plate at a height of between 1 and 2meters above an even surface such
as short grass.
7.2.6 Installation for measuring albedo
An albedometer consists of two identical pyranometers that measure the incident radiation and the radiation
reflected by the surface below. Albedo is the ratio of the two radiation measurements and varies from 0 (dark) to 1
(bright).
1
2
3
6
4
5
1 Albedo mounting plate
2 Sun shield
3 Pyranometer
4 Glare screen
5 Mast
6 Equator
4Mount the upper pyranometer.
4Mount the lower pyranometer.

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7.2.7 Installation for measuring diffuse radiation
For the diffuse radiation to be measured, the direct radiation on the pyranometer’s glass dome must be blocked.
The direct radiation can be blocked using a static shadow ring or a two-axis automatic sun tracker.
5
3
1
2
4
Mounting static shadow ring
1 Sun
2 Shadow ring
3 Pyranometer
4 Mounting bracket
5 Equator
Because the sun moves across the sky, the static shadow ring interrupts part of the diffuse radiation and needs to
be regularly adjusted. At times the shadow ring intercepts a significant proportion of the diffuse sky radiation.
Therefore, the recorded data must be revised.
1
2
3
4
5
Mounting automatic sun tracker
1 Sun
2 Shadow ball
3 Pyranometer
4 Sun tracker
5 Shading assembly
The automatic sun tracker uses the information regarding its location and the time to calculate the position of the
sun. This allows the tracker to be oriented exactly towards the sun whatever the weather. Using a shadowing
fixture on the tracker, the pyranometer’s glass dome can be shaded all year round without any need for
adjustment.

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7.3 Electrical installation
7.3.1 Electrical connections
SMP pyranometers are supplied with a waterproof connector pre-wired to 10m of high quality yellow cable with 8
wires and a shield covered with a black sleeve.
iLong cables may be used if the cable resistance is less than 0.1% of the impedance of the readout
equipment for the analog outputs. This may affect the baud rate of the RS-485 digital connection.
7.3.2 Grounding pyranometer
NOTICE
Damage due to power or ground loops!
Connecting the RS-485 to a grounded circuit and the analog output to a floating circuit can cause ground loops.
This may cause differential voltages that will damage the instrument.
4Use either the analog or the digital output.
4Observe the maximum differential voltage of 70VDC between one of the two Modbus® RS-485 lines (yellow
and gray) and the power ground (black) or RS-485 common line (blue).
Lightning can induce high voltages in the shield but these will be led off at the pyranometer or readout equipment.
The shield of the cable is connected to the aluminium pyranometer housing through the connector body.
4Secure the pyranometer with the leveling screws to a metal support with a good connection to ground, e.g. to a
lightning coductor.
4Do not connect the cable shield.
4If there is no good ground connection at the pyranometer, then connect the shield at the cable end to ground
at the readout equipment.
7.3.3 Power connection
The minimum supply voltage for the pyranometer is 5VDC. 5-volt-power can only be used with a short cable,
maximum 10m. To ensure reliable performance, a voltage of 12VDC is recommended. For the output of the
power supply, it is recommended to protect it with a fast blowing fuse of maximum 250mA rating.
7.3.4 Power consumption
Typical power consumption SMP-V for maximum output (1V)
Voltage on the pyranometer (V DC) Current (mA) Power (mW)
5 10.0 50
12 4.5 55
24 2.5 60
– Maximum power consumption 65mW at the highest input voltage.
– Maximum input current 12.5mA at the lowest input voltage.
– Maximum inrush current 200mA.

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Typical power consumption SMP-A for max output (20 mA)
Voltage on the pyranometer (V DC) Current (mA with 100Ω load
resistor)
Power (mW)
5 28 77
12 24 83
24 6 100
The above Megawatt values represent the dissipation within the SMP-A. For the total power the energy in the load
resistor has to be added.
For supply voltages below 12 Volts or above 20 Volts use a load resistor of less than 500 Ω to keep the power
consumption as low as possible.
7.3.5 Analog voltage output
The SMP-V (voltage output versions) have been factory set such that an output of 0Volts represents -200W/m2 (this
will never be reached in practice), and the full-scale output of 1Volt represents 2000 W/m2. The voltage output
range in W/m2 can be changed with the supplied PC software.
The measurement range must start from a negative value in order to show (small) negative readings, for example
night-time offsets, because the analog output itself cannot go negative. For the default setting of 0 to 1Volt
representing -200 to 2000W/m2 the range is actually 2200W/m2 with a zero offset of 200W/m2.
The irradiance value (E↓solar) for the default setting can be calculated as shown below:
E↓solar= (Vx2200) - 200
E↓solar= Solar radiation
[W/m2]V = Output of radiometer [Volt]
If the pyranometer is used in atmospheric conditions it is advised to keep the range as factory set.
7.3.6 Analog current output
The SMP-A (current output versions) have been factory set such that an output of 4mA represents 0W/m2 and the
full-scale output of 20mA represents 1600W/m2. The current output range in W/m2 can be changed with the
supplied PC software. The maximum recommended irradiance for the SMP3 and SMP6 are 2000W/m2 and for the
SMP10 and SMP22 are 4000W/m2.
Negative inputs will make the output go below 4mA and no zero offset is needed. For the default setting of 4 to
20mA representing 0 to 1600W/m2, each mA represents 100W/m2.
The irradiance value (E↓solar) for the default setting can be calculated as shown below:
E↓solar= (mA - 4) x 100
E↓solar= Solar radiation
[W/m2]mA = Output of radiometer [mA]

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7.3.7 Connecting to computer
NOTICE
Damage due to lack of insulation!
The power supply units of portable computers such as laptops can generate large voltage peaks. This may cause
damage to the instrument’s digital interface.
4Ensure that the converter has galvanic separation between the inputs and outputs.
The instrument must be connected to a computer via an RS-485 converter with a USB port.
Red– not connected
Green – analog out +
Brown – analog out -
Yellow– Modbus® RS-485
Gray– Modbus® RS-485
Blue– Modbus® common
White– power 5 to 30 V DC
Black– power ground
RS-485 USB converter
Connection to RS-485 converter
4Ensure that the power supply is switched off.
4Connect the white wire to the black wire on the power supply unit.
4Connect the yellow, gray and blue wires to the RS-485 converter.
4Isolate and seal the red wire and any other wires when they are not in use.
4Align the indentation on the connector with the indentation on the instruments’s connection socket.
4Plug the connector into the connection socket.
4Turn the locking ring clockwise and tighten it hand tight to secure the connector.
NOTICE!The seal may be damaged by overtightening!
4Switch on the power supply.
4Switch on the computer.
iIt may take three hours for the pyranometer to reach a stable temperature. During this time, the irradiation
measurements may deviate from the final measurements.