GHM DeltaOHM LPPYRA05 User manual

Operating manual
Albedometer
LPPYRA05
www.deltaohm.com
English
Keep for future reference.

LPPYRA05 - 2 - V2.2
TABLE OF CONTENTS
1 INTRODUCTION .................................................................................................... 3
2 WORKING RINCI LE ........................................................................................... 4
3 INSTALLATION ..................................................................................................... 5
4 ELECTRICAL CONNECTIONS .................................................................................. 7
5 MEASUREMENT ..................................................................................................... 8
6 MAINTENANCE ...................................................................................................... 9
7 TECHNICAL S ECIFICATIONS ............................................................................. 10
8 SAFETY INSTRUCTIONS ...................................................................................... 11
9 ORDERING CODES .............................................................................................. 12

LPPYRA05 - 3 - V2.2
1 INTRODUCTION
The LPPYRA05 albedometer measures the net global radiation, as well as the albedo o
grounds (albedo is the ratio between di use radiation rom a determined sur ace and
the quantity o radiation that arrives on the sur ace).
The LPPYRA05 is manu actured mounting two LPPYRA02 pyranometers in one housing
only. The two pyranometers, one measuring the incident radiation striking the ground
[ ↓ ] and the other one measuring the re lected radiation [ ↑ ], are combined in such a
way to have the same sensitivity.
The output signals o the two pyranometers can be processed to get the desired phys-
ical quantity.
The LPPYRA05 can be used as a pyranometer or measuring global radiation. As a py-
ranometer, the LPPYRA05 is a Spectrally Flat Class B (First Class) pyranometer in ac-
cordance with ISO 9060:2018 and with the criteria o the WMO “Guide to Meteorologi-
cal Instruments and Methods o Observation”.
The albedometer is supplied actory calibrated and with a calibration report. The cali-
bration is carried out in accordance with the ISO 9847:1992 (type IIc) standard: ”Cal-
ibration o ield pyranometers by comparison to a re erence pyranometer”. The pyra-
nometer is calibrated by comparison with the re erence sample calibrated annually at
WRC (World Radiation Center).

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2WORKING RINCI LE
The LPPYRA05 albedometer is based on a pair o thermopile sensors, one o them
measuring the incident radiation on the ground [ ↓ ] and the other one the re lected
radiation [ ↑ ]. Each thermopile works as an independent pyranometer. The thermo-
pile sensitive sur ace is coated with a black matt paint, which allows the pyranometer
not to be selective at di erent wave lengths. The pyranometer spectral range is de-
termined by the transmission o the two glass domes type K5.
Radiant energy is absorbed by the thermopile black sur ace, thus creating a di erence
o temperature between the center o the thermopile (hot junction) and the pyranom-
eter body (cold junction). Thanks to the Seebeck e ect, the di erence o temperature
between hot and cold junction is converted into a Di erence o Potential.
In order to grant the thermopile a proper thermal insulation rom the wind and reduce
the sensitivity to thermal irradiance, LPPYRA05 is equipped with two concentric domes
having 50 mm and 32 mm outer diameter on each side. The domes protect the ther-
mopile rom the dust, which might change spectral sensitivity i it lies on the black
sur ace.
To prevent internal condensation orming on the internal side o 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 L YRA05
The resistance inserted in parallel to the thermopile allows to obtain the same calibra-
tion actor or both sensors.
T
h
ermopil
e
Surge
Protector
Connector
pins
Housing
To cable shield
T
h
ermopil
e
Surge
Protector

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3INSTALLATION
Be ore installing the albedometer, re ill the cartridge containing silica-gel crystals. Sili-
ca gel absorbs humidity in the dome chamber and prevents, in particular climatic con-
ditions, condensation on the internal walls o the domes and measurement alteration.
Do not touch the silica gel crystals with your hands while re illing the cartridge. Carry
out the ollowing instructions in an environment as drier as possible:
1. Loosen the three screws that ix the white shade disk.
2. Unscrew the silica gel cartridge using a coin.
3. Remove the cartridge per orated cap.
4. Open the sachet containing silica gel (supplied with the pyranometer).
5. Fill the cartridge with the silica gel crystals.
6. Close the cartridge with its own cap, paying attention that the sealing O-ring be
properly positioned.
7. Screw the cartridge to the pyranometer body using a coin.
8. Check that the cartridge is screwed tightly (i not, silica gel li e will be reduced).
9. Position the shade disk and screw it with the screws.
10. The albedometer is ready or use.
The igure below shows the operations necessary to ill the cartridge with the silica gel
crystals.
Fig. 3.1: filling the silica-gel cartridge
Silica
-
gel
cartridge
Perforated cap
Sealed sachet
of silica-gel crystals
Filling Closing the cartridge

LPPYRA05 - 6 - V2.2
•Mount the albedometer 1 – 2 m above the ground. Grass should be kept at the
same height all the year long. In snowy regions, keep the instrument above the
blanket o snow so that the distance rom the albedometer to the snow be constant.
•The albedometer 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 upper pyranometer lies. I this is not possible, select a site where obstructions
in the path o the sun rom sunrise to sunset do not exceed 5 degrees o elevation.
N.B.: The presence of obstructions on the horizon line affects significantly
the measurement of direct irradiance.
•The pyranometer must be located ar rom any kind o obstruction, which might re-
lect sunlight (or sun shadow) onto the pyranometer itsel .
•In compliance with ISO TR9901 standard and WMO recommendations, when the
pyranometer is used without the white shade disk, it must be positioned so that its
connector is pointed to the North Pole, i the instrument is used in the Northern
Hemisphere, and to the South Pole, i used in the Southern Hemisphere. In any
case, it is better to ollow this suggestion even when the shade disk is applied.
•The mounting can be made using the rod provided with the instrument. In order to
allow an accurate horizontal positioning, the pyranometer is equipped with a level-
ling device. The mast height does not exceed the pyranometer plane to avoid
measurement errors caused by any re lection or shadow o the mast itsel .
•It is pre erably to thermally insulate the pyranometer rom its mounting bracket
ensuring, at the same time, a good electrical contact to ground.
79.5
500
140
160
124
50
Fig. 3.2: fixing and dimensions
Connector
Levelling device
LPSP1
LPSP3

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4ELECTRICAL CONNECTIONS
L YRA05 has a 8-pole connector and uses the C M12AA8... optional cables, with
8-pole connector on one side and open wires on the other side.
The metallic housing of the albedometer 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
albedometer, connect the wire of the cable corresponding to the
housing to ground ( ).
The albedometer LPPYRA05 is passive and does not require power supply. It is to be
connected either to a millivoltmeter or to a data acquisition system (with at least two
inputs). Typically, the albedometer output signal does not exceed 20 mV. In order to
better exploit the albedometer eatures, the readout instrument should have 1 µV res-
olution.
Connector Function Color
1 Output positive (+Vout) upper pyranometer [↓] Red
2 Output negative (-Vout) upper pyranometer [↓] Blue
3 Not connected
4 Not connected
5 Output negative (-Vout) lower pyranometer [↑] Brown
6 Housing (C) White
7 Cable shield (SH) Black
8 Output positive (+Vout) lower pyranometer [↑] Green
12
3
456
7
8
+Vout [ ]
-Vout [ ]
SH
C
+Vout [ ]¯
-Vout [ ]¯
Fig. 4.1: L YRA05 connections
The cable shield is isolated rom the albedometer housing by means o two gas surge
arrestors, which prevents lightnings to damage the sensor. The shield has to be con-
nected to the same ground as the readout instrument. Best sa ety is achieved through
a per ect connection between housing and earth.
Connect to ground only if it is not possible to
ground locally the case of the pyranometer
CPM12AA8… cable
Albedometer
M12 male
connector
Reflected
radiation [↑]
I
ncident
radiation [↓]
Multi
-
input
data
logger
Converter
amplifier
with V or mA
output
Converter
amplifier
with V or mA
output
or
or

LPPYRA05 - 8 - V2.2
5MEASUREMENT
Each albedometer is distinguished by its own sensitivity (or calibration actor) S ex-
pressed in µV/(Wm-2) and shown in the label on the albedometer (and in the calibra-
tion report).
The sensitivity S is the same or both pyranometers.
The irradiance Ee is obtained by measuring with a multimeter the di erence o potential
DDP at the ends o the sensor and applying the ollowing ormula:
Ee = DDP / S
where:
Ee is the irradiance expressed in W/m2;
DDP is the di erence o potential expressed in µV measured by the multimeter;
S is the sensitivity o the albedometer expressed in µV/(Wm-2).
Albedo is the raction o solar radiation that is re lected rom the ground, with respect
to incident radiation:
ALBEDO = Ee [↑] / Ee [↓]
With the albedometer it is possible to calculate the net radiation making the di erence
between the incident global radiation and the re lected global radiation.

LPPYRA05 - 9 - V2.2
6MAINTENANCE
In order to grant measurements high accuracy, it is important to keep the outer glass
domes clean. Consequently, the more the domes will be kept clean, the more meas-
urements will be accurate.
You can wash it using water and standard papers or lens. I necessary, use pure
ETHYL alcohol. A ter using alcohol, clean again the domes with water only.
Because o the high temperature changes between day and night, some condensation
might appear on the domes o the pyranometers. In this case the per ormed reading
is highly over-estimated. To minimize the condensation, the albedometer is provided
with a cartridge containing dessicant material (silica-gel). The e iciency o the silica-
gel crystals decreases over time while absorbing humidity. Silica-gel crystals are e i-
cient when their color is yellow, while they turn white/translucent as soon as they
loose their e iciency. Read instructions at chapter 3 about how to replace the silica-
gel crystals. Silica-gel typical li etime goes rom 2 to 6 months depending on the envi-
ronment where the albedometer works.
To exploit all the albedometer eatures, it is highly recommended that the calibration
be checked annually.

LPPYRA05 - 10 - V2.2
7TECHNICAL S ECIFICATIONS
Sensor Thermopile
Typical sensitivity 6÷12 µV/Wm-2
Impedance 33÷45 Ω
Measuring range 0÷2000 W/m2
Viewing angle 2π sr
Spectral range (50%) 283÷2800 nm
Operating temperature/humidity -40÷80 °C / 0÷100%
Output Analog in µV/Wm-2
Connection 8-pole M12 connector
Dimensions Fig. 3.2
Weight 1.35 kg approx. (complete albedometer)
Accuracy of levelling device < 0.1°
rotection degree IP 67
MTBF > 10 years
Technical Specifications According to ISO 9060
Classification Spectrally Flat Class B
Response time (95%) < 10 s
Zero offset
a) response to a 200 W/m2 thermal
radiation
<±10W/m2
b) response to a 5 K/h change in
ambiente temperature
<±4W/m2
c) total zero offset including the
effects a), b) and other sources
<±15W/m2
Long-term instability (1 year) <±1 %
Non-linearity <±1 %
Response according to the cosine law <±18 W/m2
Spectral error < ±0.5 %
Temperature response (-10…+40°C) < 1.5 %
Tilt response <±2 %

LPPYRA05 - 11 - V2.2
8SAFETY INSTRUCTIONS
General safety instructions
The instrument has been manu actured and tested in accordance with the sa ety
standard EN61010-1:2010 “Sa ety requirements or electrical equipment or meas-
urement, control and laboratory use” and has le t the actory in per ect sa ety tech-
nical conditions.
The instrument proper operation and operating sa ety can be ensured only i all
standard sa ety measures as well as the speci ic measures described in this manual
are ollowed.
The instrument proper operation and operating sa ety can be ensured only in the cli-
matic conditions speci ied in this manual.
Do not use the instruments in places where there are:
•Corrosive or lammable gases.
•Direct vibrations or shocks to the instrument.
•High-intensity electromagnetic ields, static electricity.
User obligations
The instrument operator shall ollow the directives and regulations below that re er to
the treatment o dangerous materials:
•EEC directives on workplace sa ety.
•National law regulations on workplace sa ety.
•Accident prevention regulations.

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9ACCESSORIES ORDERING CODES
L S 1 UV-resistant shade disk or the upper pyranometer (spare part).
L S 3 UV-resistant shade disk or the lower pyranometer (spare part).
C M12AA8… Cable with 8-pole M12 connector on one end, open wires on the
other end. Length 2 m (CPM12AA8.2), 5 m (CPM12AA8.5) or
10 m (CPM12AA8.10).
L SG Cartridge to contain desiccant silica-gel crystals, complete with O-
ring and cap (spare part).
L G Pack o 5 sachets o silica-gel crystals.
DELTA OHM metrology laboratories LAT N° 124 are ISO/IEC 17025 accredited by
ACCREDIA for Temperature, Humidity, ressure, hotometry / Radiometry, Acous-
tics and Air Velocity. They can supply calibration certificates for the accredited
quantities.

LPPYRA05 - 13 - V2.2
NOTES

LPPYRA05 - 14 - V2.2
NOTES

GHM GROU – 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 " actory warranty" only in those cases provided by
Legislative Decree 6 September 2005 - n. 206. Each instrument is sold a ter rigorous inspections;
i any manu acturing de ect is ound, it is necessary to contact the distributor where the
instrument was purchased rom. During the warranty period (24 months rom the date o invoice)
any manu acturing de ects ound will be repaired ree o charge. Misuse, wear, neglect, lack or
ine icient maintenance as well as the t and damage during transport are excluded. Warranty does
not apply i changes, tampering or unauthorized repairs are made on the product. Solutions,
probes, electrodes and microphones are not guaranteed as the improper use, even or a ew
minutes, may cause irreparable damages.
Delta OHM repairs the products that show de ects o construction in accordance with the terms and
conditions o warranty included in the manual o the product. For any dispute, the competent court
is the Court o Padua. The Italian law and the “Convention on Contracts or the International Sales
o Goods” apply.
TECHNICAL INFORMATION
The quality level o our instruments is the result o the continuous product development. This may
lead to di erences between the in ormation reported in the manual and the instrument you have
purchased. In case o discrepancies and/or inconsistencies, please write to [e-mail].
Delta OHM reserves the right to change technical speci ications and dimensions to it the
product requirements without prior notice.
DIS OSAL INFORMATION
Electrical and electronic equipment marked with speci ic symbol in compliance
with 2012/19/EU Directive must be disposed o separately rom household waste.
European users can hand them over to the dealer or to the manu acturer 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 o electrical and electronic equipment separately rom normal waste helps to
preserve natural resources and allows materials to be recycled in an environmentally riendly
way without risks to human health.
RoHS
V2.2
21/04/2021