GHM DeltaOHM LPPYRA-Lite User manual

Operating manual
Pyranometer
LPPYRA
-Lite
www.deltaohm.com
English
Keep for future reference.

LPPYRA-Lite -2-V1.1
TABLE OF CONTENTS
1INTRODUCTION.................................................................................................... 3
2WORKING PRINCIPLE........................................................................................... 4
3INSTALLATION ..................................................................................................... 5
4ELECTRICAL CONNECTIONS.................................................................................. 8
4.1 LPPYRA-LITE CONNECTIONS .................................................................................. 8
4.2 LPPYRA-LITEAC CONNECTIONS............................................................................... 9
5MEASUREMENT ................................................................................................... 10
5.1 LPPYRA-LITE .................................................................................................. 10
5.2 LPPYRA-LITEAC .............................................................................................. 10
6MAINTENANCE.................................................................................................... 11
7TECHNICAL SPECIFICATIONS............................................................................. 12
8SAFETY INSTRUCTIONS...................................................................................... 13
9ACCESSORIES ORDERING CODES ....................................................................... 14

LPPYRA-Lite -3-V1.1
1INTRODUCTION
LPPYRA-Lite pyranometer measures the irradiance on a flat surface (W/m2). The
measured irradiance (Global Irradiance) is the sum of direct solar irradiance and dif-
fuse irradiance.
LPPYRA-Lite is a Spectrally Flat Class C (Second Class) pyranometer in accordance
with ISO 9060:2018 and with the criteria of the WMO “Guide to Meteorological In-
struments and Methods of Observation’”.
The pyranometer is available in the following versions:
•LPPYRA-Lite: PASSIVE.
The passive version can be connected to the instruments
D09847 and HD31 by using VP472 SICRAM module.
•LPPYRA-LiteAC: ACTIVE with 2-wire (current loop) 4..20 mA output (0…2000
W/m2).
The pyranometer is supplied factory calibrated. The calibration is carried out in
accordance with the ISO 9847:1992 (type IIc) standard: ”Calibration of field
pyranometers by comparison to a reference pyranometer”. The pyranometer is
calibrated by comparison with the reference sample calibrated annually at WRC (World
Radiation Center).
An optional fixing base integrating a levelling device is available as an accessory, for
installations where horizontal positioning is required.

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2WORKING PRINCIPLE
LPPYRA-Lite pyranometer is based on a thermopile sensor. The thermopile sensitive
surface is coated with a black matt paint, which allows the pyranometer not to be se-
lective at different wavelengths.
Radiant energy is absorbed by the thermopile black surface, thus creating a difference
of temperature between the center of the thermopile (hot junction) and the pyranom-
eter body (cold junction). Thanks to the Seebeck effect, the difference of temperature
between hot and cold junction is converted into a Difference of Potential.
In order to grant the thermopile a proper thermal insulation from the wind and reduce
the sensitivity to thermal irradiance, LPPYRA-Lite is equipped with a glass dome. The
dome protects the thermopile from the dust, which might change spectral sensitivity if
it lies on the black surface,
To prevent internal condensation forming on the internal side of the dome under cer-
tain climatic conditions, silica gel tablets are inserted inside the pyranometer to ab-
sorb humidity.
Fig. 2.1: scheme of principle LPPYRA-Lite (version with mV output)
Thermopile
Connector pins
Housing

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3INSTALLATION
•The pyranometer must be mounted in an easy-to-reach location in order to clean
the dome regularly and carry out maintenance. At the same time, make sure that
no buildings, constructions, trees or obstructions exceed the horizontal plane where
the pyranometer lies. If this is not possible, select a site where obstructions in the
path of the sun from sunrise to sunset do not exceed 5 degrees of elevation. N.B.:
The presence of obstructions on the horizon line affects significantly the
measurement of direct irradiance.
•The pyranometer must be located far from any kind of obstruction, which might re-
flect sunlight (or sun shadow) onto the pyranometer itself.
•In compliance with ISO TR9901 standard and WMO recommendations, the pyra-
nometer must be positioned so that its connector is pointed to the North Pole, if the
instrument is used in the Northern Hemisphere, and to the South Pole, if used in
the Southern Hemisphere.
•For fixing, use the two holes under the pyranometer body or the suitable accesso-
ries (see the figures below). In order to allow an accurate horizontal positioning,
the optional LPS40/32BL fixing base integrating a levelling device can be used.
The mast height does not exceed the pyranometer plane to avoid measurement er-
rors caused by any reflection or shadow of the mast itself.
•It is preferably to thermally insulate the pyranometer from its mounting bracket
ensuring, at the same time, a good electrical contact to ground.
•
Fig. 3.1: dimensions and fixing holes

LPPYRA-Lite -6-V1.1
LPS40/32
LPS40/32BL - Integrated levelling device
Fig. 3.2: fixing adapters from 40 to 32 mm holes centre distance
Fig. 3.3: fixing on HD2003.77/40 clamping
Fig. 3.4: fixing on LPS3 bracket
Levelling
device

LPPYRA-Lite -7-V1.1
Fig. 3.3: fixing on LPRING04 adjustable holder

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4ELECTRICAL CONNECTIONS
LPPYRA-Lite has a 4-pole connector and uses the CPM12AA4... optional cables, with
4-pole connector on one side and open wires on the other side.
The metallic housing of the pyranometer should preferably be
grounded (
) locally. In this case, do not connect the wire of
the cable corresponding to the housing to prevent ground loops.
Only if it is not possible to ground locally the metallic case of the
pyranometer, connect the wire of the cable corresponding to the
housing to ground ( ).
In the powered version LPPYRA-LiteAC, inside the housing there is a
surge protector connected between the housing itself and the elec-
tronic circuit. Grounding the housing allows the correc
t protection
function (in particular against lightning) of the surge protector.
4.1 LPPYRA-Lite CONNECTIONS
The pyranometer LPPYRA-Lite is passive and does not require power supply. It is to
be connected either to a millivoltmeter or to a data acquisition system. Typically, the
pyranometer output signal does not exceed 20 mV. In order to better exploit the py-
ranometer features, the readout instrument should have 1 µV resolution.
Connector Function Color
1 +Vout Red
2
-Vout
Blue
3
Housing (C)
White
4
Cable shield (SH)
Black
Fig. 4.1: LPPYRA-Lite connections
CPM12AA4… cable
Pyranometer M12
male connector
Datalogger or
converter/amplifier
with Vor mA output
Connect to ground only if it is not possible to
ground locally the housing of the pyr
anometer
To circuit
Housing
Surge
protector

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4.2 LPPYRA-LiteAC CONNECTIONS
The pyranometer LPPYRA-LiteAC has 4…20 mA output and requires 10…28 Vdc ex-
ternal power supply. It is to be connected to a power supply and an instrument with
4…20 mA input as shown in fig. 4.2. The load resistance of the instrument reading the
signal must be ≤500 Ω.
Connector Function Color
1
Positive (Iin)
Red
2
Negative (Iout)
Blue
3
Housing (C)
White
4
Cable shield (SH)
Black
Fig. 4.2: LPPYRA-LiteAC connections
CPM12AA4… cable
Pyranometer M12
male connector
Power supply
Connect to ground only if it is not possible to
ground locally the housing of the pyr
anometer
Instrument with
4…20 mA input

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5MEASUREMENT
Below are the ways to calculate the global irradiance.
5.1 LPPYRA-Lite
Each pyranometer is distinguished by its own sensitivity (or calibration factor) S ex-
pressed in µV/(Wm-2) and shown in the label on the pyranometer (and in the optional
calibration report).
The irradiance Eeis obtained by measuring with a multimeter the difference of potential
DDP at the ends of the sensor and applying the following formula:
Ee= DDP / S
where:
Eeis the irradiance expressed in W/m2;
DDP is the difference of potential expressed in µV measured by the multimeter;
Sis the sensitivity of the pyranometer expressed in µV/(Wm-2).
5.2 LPPYRA-LiteAC
The 4…20 mA output signal corresponds to the 0…2000 W/m2irradiance range.
The irradiance Eeis obtained by measuring with a multimeter the current Iout absorbed
by the sensor and applying the following formula:
Ee= 125 •(Iout - 4)
where:
Eeis the irradiance expressed in W/m2;
Iout is the current expressed in mA absorbed by the pyranometer.

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6MAINTENANCE
In order to grant measurements high accuracy, it is important to keep the outer glass
dome clean. Consequently, the more the dome will be kept clean, the more measure-
ments will be accurate.
You can wash it using water and standard papers for lens. If necessary, use pure
ETHYL alcohol. After using alcohol, clean again the dome with water only.
To exploit all the pyranometer features, it is highly recommended that the calibration
be checked annually.

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7TECHNICAL SPECIFICATIONS
Sensor Thermopile
Typical sensitivity 5÷15 µV/Wm-2 or normalized 7 µV/Wm-2
Measuring range 0÷2000 W/m2
Viewing angle 2πsr
Spectral range (50%) 300÷2800 nm
Output LPPYRA-Lite: µV/Wm-2 (impedance 33...45 Ω)
LPPYRA-LiteAC: 2-wire (current loop) 4…20 mA
(RL≤500 Ω)
Power supply LPPYRA-Lite: passive version, no power required
LPPYRA-LiteAC: 10…28 Vdc
Consumption LPPYRA-Lite: passive version, no power required
LPPYRA-LiteAC: equal to output signal (4…20 mA)
Connection 4-pole M12 connector
Dimensions Fig. 3.1
Weight 150 g approx.
Operating temperature/humidity -40÷80 °C / 0÷100%
Protection degree IP 67
MTBF > 10 years
Technical Specifications According to ISO 9060:2018
Classification Spectrally Flat Class C
Response time (95%) < 25 s
Zero offset
a) response to a 200 W/m2thermal
radiation
<±20W/m2
b) response to a 5 K/h change in
ambiente temperature <±6W/m2
c) total zero offset including the
effects a), b) and other sources <±30W/m2
Long-term instability (1 year) <±2%
Non-linearity <±2%
Response according to the cosine law <±25W/m2
Spectral error <±2%
Temperature response (-10…+40°C) < 3 %
Tilt response <±3%

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8SAFETY INSTRUCTIONS
General safety instructions
The instrument has been manufactured and tested in accordance with the safety
standard EN61010-1:2010 “Safety requirements for electrical equipment for meas-
urement, control and laboratory use” and has left the factory in perfect safety tech-
nical conditions.
The instrument proper operation and operating safety can be ensured only if all
standard safety measures as well as the specific measures described in this manual
are followed.
The instrument proper operation and operating safety can be ensured only in the cli-
matic conditions specified in this manual.
Do not use the instruments in places where there are:
•Corrosive or flammable gases.
•Direct vibrations or shocks to the instrument.
•High-intensity electromagnetic fields, static electricity.
User obligations
The instrument operator shall follow the directives and regulations below that refer to
the treatment of dangerous materials:
•EEC directives on workplace safety.
•National law regulations on workplace safety.
•Accident prevention regulations.

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9ACCESSORIES ORDERING CODES
LPS40/32 Fixing adapter from 40 to 32 mm holes centre distance.
LPS40/32BL Fixing adapter from 40 to 32 mm holes centre distance. With in-
tegrated levelling device. Accuracy of levelling device < 0.2°.
LPS3 Fixing bracket for the pyranometer, suitable for ∅40 ÷ 50 mm
mast. Installation on horizontal or vertical mast. LPS40/32…
adapter is required.
LPRING04 Adjustable holder for mounting the pyranometer in an inclined
position on Ø 40 mm mast with internal thread. LPS40/32…
adapter is required.
HD2003.77/40 Clamping for mast ∅40 mm to install the pyranometer on a
transverse mast.LPS40/32… adapter is required.
CPM12AA4…Cable with 4-pole M12 connector on one end, open wires on the
other end. Length 2 m (CPM12AA4.2), 5 m (CPM12AA4.5) or 10 m
(CPM12AA4.10).
DELTA OHM metrology laboratories LAT N° 124 are ISO/IEC 17025 accredited by
ACCREDIA for Temperature, Humidity, Pressure, Photometry / Radiometry, Acous-
tics and Air Velocity. They can supply calibration certificates for the accredited
quantities.

GHM GROUP – Delta OHM | Delta Ohm S.r.l. a socio unico
Via Marconi 5 | 35030 Caselle di Selvazzano | Padova | ITALY
Phone [phone] | Fax [phone]
www.deltaohm.com | [e-mail]
WARRANTY
Delta OHM is required to respond to the "factory warranty" only in those cases provided by
Legislative Decree 6 September 2005 - n. 206. Each instrument is sold after rigorous inspections;
if any manufacturing defect is found, it is necessary to contact the distributor where the
instrument was purchased from. During the warranty period (24 months from the date of invoice)
any manufacturing defects found will be repaired free of charge. Misuse, wear, neglect, lack or
inefficient maintenance as well as theft and damage during transport are excluded. Warranty does
not apply if changes, tampering or unauthorized repairs are made on the product. Solutions,
probes, electrodes and microphones are not guaranteed as the improper use, even for a few
minutes, may cause irreparable damages.
Delta OHM repairs the products that show defects of construction in accordance with the terms
and conditions of warranty included in the manual of the product. For any dispute, the competent
court is the Court of Padua. The Italian law and the “Convention on Contracts for the International
Sales of Goods” apply.
TECHNICAL INFORMATION
The quality level of our instruments is the result of the continuous product development. This may
lead to differences between the information reported in the manual and the instrument you have
purchased. In case of discrepancies and/or inconsistencies, please write to [e-mail].
Delta OHM reserves the right to change technical specifications and dimensions to fit the
product requirements without prior notice.
DISPOSAL INFORMATION
Electrical and electronic equipment marked with specific symbol
in compliance
with 2012/19/EU Directive must be disposed of separately from household waste.
European users can hand them over to the dealer or to the manufacturer when
purchasing a
new electrical and electronic equipment, or to a WEEE collection
point designated by local authorities. Illegal disposal is punished by law.
Disposing of electrical and electronic equipment separately from normal waste helps to
preserve natural resources and allows materials to be recycled in an environmentally friendly
way without risks to human health.
V1.1
02/2022