Delta OHM LP UVA 02 User manual

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Our instruments' quality level is the results of the product continuous
development. This can bring about differences between the information written
in this manual and the instrument that you have purchased. We cannot entirely
exclude errors in the manual, for which we apologize.
The data, figures and descriptions contained in this manual cannot be legally
asserted. We reserve the right to make changes and corrections without prior
notice.
REV. 1.0
10 jan. 2007
LP UVA 02

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LP UVA 02
1 Introduction
The LP UVA 02 radiometer measures the broadband UVA irradiance on a plane
surface (Watt/ m2). Measured irradiance is the result of the sum of direct solar
irradiance and of diffuse irradiance.
The radiometer can measure the UVA irradiance in closed room too.
The radiometer is produced in three versions:
LP UVA 02 PASSIVE*
LP UVA 02 AC ACTIVE , 4..20mA CURRENT output
LP UVA 02 AV ACTIVE , 0..1 or 0..5 or 0..10 V VOLTAGE output,
to be defined at the order.
* Using SICRAM Module VP 472 it is possible to connect passive pyranometer to
Indicator D09847.
2 Working Principle
LP UVA 02 radiometer is based on a solid state sensor, the spectral match with the
desire curve is obtain using special filter. The relative spectral response is reported on
figure 1.
Fig1
In order to protect the diffuser from the dust, LP UVA 02 is equipped with a 50mm
glass dome.
The cosine low response is obtained with a particular shaped PTFE diffuser in
figure 2 the cosine error versus angle of incident is reported
1.00E-03
1.00E-02
1.00E-01
1.00E+00
290 310 330 350 370 390 410
Lambda (nm)
Relative Spectral response

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Fig.2
The good cosine low response of LP UVA 02 allow to use the radiometer at any
sun ‘s zenithangle .
3 Installation and Mounting of the Radiometer for the
Measurement of Global Radiation:
Before installing the radiometer, refill the cartridge containing silica-gel crystals.
Silica gel absorbs humidity in the dome chamber and prevents (in particular climatic
conditions) internal condensation forming on the internal walls of the domes and
measurement alteration.
Do not touch the silica gel crystals with your hands while refilling the cartridge. Carry
out the following instructions in an environment as drier as possible:
1- Loosen the three screws that fix the white shade disk
2- Unscrew the silica gel cartridge using a coin
3- Remove the cartridge perforated cap
4- Open the sachet containing silica gel (supplied with the radiometer)
5- Replace 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 radiometer body using a coin
8- Check that the cartridge is screwed tightly (if not, silica gel life will be
reduced)
9- Position the shade disk and screw it with the screws
10- The radiometer is ready for use
-2
0
2
4
6
8
10
0 1020304050607080
Angle
Cosini error

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Figure N.3 shows the operations necessary to fill the cartridge with the silica
gel crystals.
Fig. 3
•The LP UVA 02 radiometer has to be mounted in a readily accessible location
to clean the dome regularly and to carry out maintenance. At the same time, check that
no building, construction, tree or obstruction exceeds the horizontal plane where the
radiometer lays. If this is not possible, select a site where obstructions do not exceed 5
degrees of elevation, in the path followed by the sun, between earliest sunrise and
latest sunset. N.B The presence of obstructions on the horizon line significantly
affects the measurement of direct irradiance.
•The radiometer has to be located far from any kind of obstruction, which might
reflect sunlight (or sun shadow) onto the radiometer itself.
•The LP UVA 02 radiometer is provided with a spirit level for carrying out an
accurate horizontal leveling. The adjustment is made by means of two leveling screws
that allow to adjust the radiometer inclination. Use the two 6mm-diameter holes and a
65mm interaxial distance to mount the instrument on a plane. Remove the shade disk
to access the holes and reposition it after mounting (see fig. 4).
•The LP S1 mounting kit (figure 5), supplied on demand as an accessory, allows
an easy mounting of the radiometer on a mast. The mast maximum diameter shall not
exceed 50 mm. The operator shall take care that the mast height does not exceed the
radiometer plane to avoid measurement errors caused by any reflection or shadow of
the mast itself. To fix the radiometer to the mounting bracket, remove the shade disk
loosening the three screws, fix the radiometer, and mount the white shade disk again.
•It is suggested to thermally isolate the radiometer from its mounting brackets,
and to check that the electrical contact with the ground be done properly
AB
CD
Silica-gel cartridge
Perforated Cap
Sealed sachet of silic
a
Filling Closing the cartidge
LP G
LP SG

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Spirit Level
104 mm
50.0 mm
65.0 mm
79.0 mm
D6 mm
165 mm LP UVA 02 AC
LP UVA 02 AV
LP UVA 02
Fixing holes
HD9906.47 HD9906.47.2
HD9906.46
HD9906.46.2
Fig 4
HD 2003.83
HD 2003.77C
HD 2003.77
HD 2003.79
HD 2003.85
HD 2003.84
Pyranometer LP UVA 02
with LP S1
LP S1

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Fig.5
4 Electrical Connection and Requirements for Electronic
Readout Devices:
LP UVA 02 is produced in 3 versions, LP UVA 02, LP UVA 02 AC and LP UVA 02
AV.
•LP UVA 02 radiometer is passive and it does not require any power supply.
•LP UVA 02 AC, AV are active and need power supply.
Required voltage is as follows:
8-30 Vcc for LP UVA 02 AC and LP UVA 02 AV with 0..1V and 0..5V autput
supply.
14-30 Vcc for LP UVA 03 AV with 0..10 V output.
•All version are supplied with a 4 pole connector.
•The optional cable is terminated with a connector at one end and it is made of
PTFE UV-proof. It is provided with 3 wires and a braided wire (shield). Cable colors
and connector poles are matched as follow (figure 6):
Fig.6
LP UVA 02
Connector Function Color
A Shield ( ) Black
B Vout (+) Red
C Vout (-) Blue
D Housing ( ) White
LP UVA 02 AC
Connector Function Color
A Shield ( ) Black
B Positive (+) Red
C Negative (-) Blue
D Housing ( ) White
LP UVA 02 AV
Connector Function Color
A Shield ( ) Black
B (+) Vout Red
C (-) Vout e (-)Vcc Blue
D (+) Vcc White

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•The LP UVA 02 radiometer has to be connected either to a millivoltmeter or to
a data acquisition system with input resistance > 5MΩ. Typically, the radiometer
output signal does not exceed 100 mV. In order to better exploit the radiometer
features, the readout instrument should have a 1μV resolution.
fig. 7
•LP UVA 02 AC is to be connected to a DMM and a power supply as show below
(Figure 8).To read the signal, the load resistance must be ≤500Ω
LP UVA 02 AC
+Vcc
I out
Power Supply
+
+
-
-
DMM
C
B
Fig. 8
•LP UVA 02 AV is to be connected to a DMM and a power supply as show below
(Figure 9). To read the signal, the load resistance must be ≥100kΩ
LP UVA 02 AV
+Vout
-Vcc,
- Vout
Power Supply
+
+
-
-
DMM
+ Vcc
C
D
B
Fig. 9
Blue Red
Screeno (Black)

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5 Maintenance:
It is important to keep the outer glass dome clean to grant measurement best accuracy.
Consequently, the more the dome will be kept clean, the more measurements will be
accurate. Washing can be made using water and standard papers for lens, or, in some
cases, using pure ethyl alcohol. After using alcohol, clean again the dome with water
only.
Because of the high rise/fall in temperature between day and night, some condensation
might appear on the radiometer dome. To minimize the condensation growth, the
radiometer is provided with a cartridge containing dessicant material: Silica gel. The
efficiency of the Silica gel crystals decreases in the course of time while absorbing
humidity. Silica gel crystals are active when their color is yellow, while they turn blue
as soon as they loose their power. Read instructions at paragraph “3” about how to
replace them. Silica gel typical lifetime goes from 2 to 6 months depending on the
environment where the radiometer works.
6 Calibration and Measurements:
LP UVA 02
The radiometer S sensitivity (or calibration factor) allows to determine the irradiance
by measuring a signal in Volts at the ends of the resistance which short-circuits the
terminals of the photodiode ends. The S factor is measured in μV/(Wm-2).
Once the difference of potential (DDP) has been measured at the ends of the sensor,
the Eeirradiance is obtained applying the following formula:
Ee= DDP/S
Where:
Ee: is the Irradiance expressed in W/m2,
DDP: is the difference of potential expressed in μV and measured by the
multimeter,
S: is the calibration factor in μV/(W/m2) shown on the radiometer label
(and mentioned in the calibration report) .
LP UVA 02 AC
The radiometer sensitivity is set so that:
4..20 mA = 0..200 W/m2
To obtain irradiance the following procedure is to be applied:
-once you know the current ( Iout) absorbed by the instrument and measured with
the DMM, following formula must be applied:
(
)
mAIe out
E45.12
−
⋅
=
where;
Ee: Irradiance in W/m2,
Iout: current in mA absorbed by the radiometer

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LP UVA 02 AV
The pyranometer sensitivity is set so that according to the version:
0..1 V = 0..200 W/m2
0..5 V = 0..200 W/m2
0..10 V = 0..200 W/m2
To obtain irradiance the following procedure is to be applied:
-once you know the instrument output voltage (Vout) measured with the DMM,
following formula must be applied:
oute VE
⋅
=200 for the version 0…1 V
oute VE
⋅
=40 for the version 0…5 V
oute VE
⋅
=20 for the version 0…10 V
where;
Ee: Irradiance in W/m2,
Vout: Output voltage (in Volt) measured by the voltmeter
Radiometers are factory calibrated one by one and they are marked by their own
calibration factor.
The calibration is carried out following procedure N° DHLF-E-59. This procedure is
used in the SIT calibration center N° 124 for the calibration of UVA radiometer.
The calibration was performed by reference to Delta Ohm srl primary standard with
monochromatic light at 365 nm obtained separating the emission line of a Xe-Hg lamp
with an inferential filter. To get best performances from your LP UVA 02 it is strongly
recommended that the calibration be checked annually.
At the moment no international agreement exist for the calibration of this kind
of radiometer, so the calibration coefficient is dependent from the calibration
procedure like reported in the following article:
“Source of Error in UV Radiation Measurements “, T. C. Larason, C. L.
Cromer on “Journal of Reaserch of the National Institute of Standards and
Technology” Vol. 106, Num. 4, 2001. (The article is free on the NIST’s WEB
site at the following address : http://www.nist.gov/jers)

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7 Technical Specifications:
Typical sensitivity: 150 ÷350μV/(W/m2) LP UVA 02
4..20 mA (0-2000 W/m2) LP UVA 02AC
0..1,5,10V (0-2000 W/m2) LP UVA 02AV
Response time: <0.5 sec (95%)
Impedance: 5 ÷7.5 KΩ
Measuring range: 0-1000 W/m2
Viewing angle: 2πsr
Spectral range: 327 nm ÷384 nm (1/2)
312 nm ÷393 nm (1/10)
305 nm ÷400 nm (1/100)
Operating temperature: -40 °C ÷80 °C
Cosine response: < 8 % (tra 0° e 80°)
Long-term non-stability: <⏐±3⏐%
(1 year)
Non-linearity: <1 %
Temperature response: < 0.1%/°C
Dimensions: figura 4
Weight: 0.90 Kg

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8 Ordering Codes
ORDERING CODE ARTICLE
LP UVA 02-5 Radiometer complete with shade disk,
desiccant sachet with silica gel crystals,
2 silicagel cartridges, spirit level, 4 pole
plug and Calibration Report.
LP UVA 02 AC Radiometer complete with shade disk,
desiccant sachet with silica gel crystals,
2 silicagel cartridges, spirit level, 4 pole
plug and Calibration Report. 4..20 mA
signal Output
LP UVA 02 AV Radiometer complete with shade disk,
desiccant sachet with silica gel crystals,
2 silicagel cartridges, spirit level, 4 pole
plug and Calibration Report. 0..1V,
0..5V, 0..10V signal output (to be
defined when order)
CP AA 1.5 4 pole plug with UV proof cable, L=5m.
CP AA 1.10 4 pole plug with UV proof cable,
L=10m.
HD 2003.85 Fixing kit to mount height pyranometer
on φ40mm mast (HD2003.84 +
HD2003.85 + HD2003.79)
HD 2003.79 Fixing kit to mount pyranometers on
clamping φ40mm (HD2003.77 +
HD2003.79)
HD 2003.77 Clamping for mast φ40mm
LP SP1 UV resistant plastic shade disk (BASF
LURAN S777K)
LP S1 Mounting kit for LP UVA 02: bracket
for attachment to a mast, including
fasteners and leveling screws.
LP SG Desiccant sachet with silica gel crystals,
complete with inner O-ring and cap.
LP G Pack of 5 cartridges of silica gel crystals

CE CONFORMITY
Safety EN61000-4-2, EN61010-1 LEVEL 3
Electrostatic discharge EN61000-4-2 LEVEL 3
Electric fast transients EN61000-4-4 LEVEL 3
Voltage variations EN61000-4-11
Electromagnetic interference susceptibility IEC1000-4-3
Electromagnetic interference emission EN55020 class B
This guarantee must be sent together with the instrument to our service centre.
N.B.: Guarantee is valid only if coupon has been correctly filled in all details.
RENEWALS
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Date Date
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Date Date
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Instrument type LP UVA 02
Serial number
GARANZIA GUARANTEE
GARANTIE GARANTIA
GUARANTEE CONDITIONS
All DELTA OHM instruments have been subjected to strict tests and are guaranteed for 24 months
from date of purchase. DELTA OHM will repair or replace free of charge any parts which it considers
to be inefficient within the guarantee period. Complete replacement is excluded and no request of
damages are recognized. The guarantee does not include accidental breakages due to transport,
neglect, incorrect use, incorrect connection to voltage different from the contemplated for the
instrument. Furthermore the guarantee is not valid if the instrument has been repaired or tampered
by unauthorized third parties. The instrument has to be sent to the retailer without transport charge.
For all disputes the competent court is the Court of Padua.
RoHS
2002/95/EC