Delta OHM LPUVB02 User manual

Operating manual
UVB Radiometer
LPUVB02
www.deltaohm.com
English
Keep for future reference.

LPUVB02 -2-V2.0
TABLE OF CONTENTS
1INTRODUCTION .................................................................................................... 3
2WORKING PRINCIPLE........................................................................................... 4
3INSTALLATION ..................................................................................................... 5
4ELECTRICAL CONNECTIONS.................................................................................. 8
5MEASUREMENT ..................................................................................................... 9
6MAINTENANCE.................................................................................................... 10
7TECHNICAL SPECIFICATIONS ............................................................................. 11
8SAFETY INSTRUCTIONS ...................................................................................... 12
9ACCESSORIES ORDERING CODES ....................................................................... 13

LPUVB02 -3-V2.0
1INTRODUCTION
The LPUVB02 radiometer measures the global irradiance in the UVB spectral range on
a flat surface (W/m2). In particular, the instrument spectral sensitivity is centred at
304 nm with a 5 nm bandwidth (FWHM - Full Width at Half Maximum).
The global irradiance is the sum of the direct solar irradiance and the sky diffuse irra-
diance on a surface parallel to the ground. Unlike the visible spectrum, where the di-
rect component prevails over the diffuse component, in the UVB spectral region the
light is strongly diffused by atmosphere and thus the two components are equivalent;
therefore it is of primary importance to measure both the components accurately.
The probe is typically used in the following fields:
•Monitoring the ozone layer. The radiation around 295…315 nm is strongly
absorbed by ozone located in the stratosphere, therefore each small variation of the
ozone layer corresponds to an increase or decrease of the UV radiation reaching the
ground.
•Effects of UVB radiation (the most harmful to human health) on living beings.
•UVB radiation measurement in workplaces.
The radiometer requires external power supply.
The radiometer is manufactured to operate for long periods without maintenance (if
powered correctly). This characteristic makes it suitable for use in meteorological sta-
tions.
A Pt100 temperature sensor is placed inside the radiometer in order to control its
temperature. Internal temperature must remain within the specified operating range,
otherwise measurements could be affected by systematic errors higher than those
stated. Exposure to temperature higher than +60 °C can alter the interferential filters
spectral characteristics.

LPUVB02 -4-V2.0
2WORKING PRINCIPLE
The LPUVB02 radiometer is based on a solid state photodiode whose spectral response
was adapted to that desired by using special interferential filters. In particular, the
used photodiode and filters have exceptional stability characteristics, both in tempera-
ture and over time. This allowed manufacturing of an instrument that does not need
heating, thus reducing energy consumption.
Particular attention has been given to filter design so as to make the instrument com-
pletely blind to wavelengths outside the pass-band of interest. The solar energy within
the 302 nm – 308 nm spectral band is only 0.01% of the total energy from the sun
reaching Earth's surface.
The relative spectral response curve is shown in Fig. 2.1 (in linear scale) and Fig. 2.2
(in logarithmic scale).
Fig. 2.1 Fig. 2.2
The LPUVB02 is provided with a 50 mm external diameter dome in order to supply a
suitable protection of the sensor to the weather agents. Quartz was chosen due to its
optimum transmission in the UV range.
The response in accordance with the cosine law has been obtained thanks to the par-
ticular shape of the diffuser and of the housing. The deviation between the theoretical
response and the measured one is shown in the Fig. 2.3.
Fig. 2.3
The excellent relation between the response of the radiometer and the cosine law al-
lows using the instrument also when the sun has a very low raising (the UVB diffuse
radiation increases as the sun moves away from the zenith, therefore the error on the
direct radiation, due to the imperfect response according to the cosine law, becomes
negligible on the measurement of the global radiation).
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
290 295 300 305 310 315 320
Lambda (nm)
Risposta Spettrale Relativa
1.0E-06
1.0E-05
1.0E-04
1.0E-03
1.0E-02
1.0E-01
1.0E+00
290 310 330 350 370 390
Lambda (nm)
Risposta Spettrale Relativa
-2
0
2
4
6
8
10
010 20 30 40 50 60 70 80
Angle
% departure from theoretical response
Relative spectral response
Relative spectral response
% deviation from theoretical response

LPUVB02 -5-V2.0
3INSTALLATION
Before installing the radiometer, refill the cartridge containing the silica-gel crystals.
Silica gel absorbs humidity in the dome chamber; in case of particular climatic condi-
tions this humidity can cause condensation on the internal side of the dome and then
modify the measurement.
Do not touch the silica gel crystals with your hands and do not wet them while refilling
the cartridge. Carry out the following instructions in an environment as drier as possi-
ble.
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 the silica gel (supplied with the radiometer).
5. Fill the cartridge with the silica-gel crystals.
6. Close the cartridge with its own cap, paying attention that the sealing O-ring is
properly positioned and undamaged.
7. Screw the cartridge to the radiometer body using a coin.
8. Check that the cartridge is screwed tightly (if not, the silica-gel life will be re-
duced).
9. Position the shade disk and tighten it with the screws.
10. The radiometer is ready for use.
The following picture shows the operations necessary to fill the cartridge with the sili-
ca-gel crystals.
Fig. 3.1: filling the silica-gel cartridge
Silica-gel cartridge
Sealed sachet of sili-
ca-gel crystals
Closing the cartridge
Filling
Perforated cap

LPUVB02 -6-V2.0
•The radiometer 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 radiometer 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.
•The radiometer must be located far from any kind of obstruction, which might re-
flect sunlight (or sun shadow) onto the radiometer itself.
•For fixing, use the holes on the radiometer body (remove the shade disk to access
the holes and reposition it after mounting) or the suitable accessories (see the fig-
ures below). In order to allow an accurate horizontal positioning, the radiometer is
equipped with a levelling device: the adjustment is made by means of the two lev-
elling screws that allow adjusting the radiometer inclination. The mast height does
not exceed the radiometer plane to avoid measurement errors caused by any re-
flection or shadow of the mast itself.
•It is preferably to thermally insulate the radiometer from its mounting bracket en-
suring, at the same time, a good electrical contact to ground.
Fig. 3.2: fixing holes and levelling device
Fixing holes ∅6 mm
Levelling
device

LPUVB02 -7-V2.0
Fig. 3.3: fixing accessories

LPUVB02 -8-V2.0
4ELECTRICAL CONNECTIONS
LPUVB02 has a 8-pole connector and uses the CPM12AA8U... optional cables.
The metallic housing of the radiometer 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
radiometer, connect the wire of the cable corresponding to the
housing to ground.
The radiometer has two analog outputs: one for temperature, normalized 0…1 V cor-
responding to -40…+60 °C, and one for UV irradiance, not normalized corresponding
to SV/(Wm-2), where S is the radiometer sensitivity.
The radiometer has to be connected to a power supply (7…30 Vdc) and instruments
with voltage input as shown in fig. 4.1. The load resistance of the instrument reading
the signal must be ≥10 kΩ.
Connector Function Color
1
Analog outputs ground (SGND)
Red
2
+Vout UV
Blue
3
Not connected
4
Cable shield (SH)
Shield
5
Power supply negative (GND)
Brown
6 +Vout Temperature White
7
Housing (C)
Black
8
Power supply positive (+Vdc)
Green
Fig. 4.1: LPUVB02 connections
Radiometer M12
male connector
CPM12AA8U… cable
Power supply
Instrument
with
voltage input
Instrument
with
voltage input

LPUVB02 -9-V2.0
5MEASUREMENT
Each radiometer is distinguished by its own sensitivity (or calibration factor) S ex-
pressed in V/(Wm-2) and shown in the label on the radiometer (and in the calibration
report).
The irradiance Eeis obtained by measuring with a multimeter the output voltage
Vout UV (difference of potential between +Vout UV and SGND) and applying the fol-
lowing formula:
Ee= Vout UV / S
where:
Eeis the irradiance expressed in W/m2;
Vout UV is the difference of potential expressed in V measured by the multimeter;
Sis the sensitivity of the radiometer expressed in V/(Wm-2).
It is possible that an offset of some tenths of millivolts (0.3 - 0.4 mV) be present on
the output signal. In this case it is recommended that the data be acquired also at
night and subtract the night-measurement offset from the performed measurements.
In the presence of a possible offset OFS (in Volt), the previous formula becomes:
Ee= (Vout UV – OFS) / S
Typically, the radiometer output signal, when exposed to the sun, does not exceed 1 V.
In order to fully exploit the radiometer features, the readout instrument should have 0.1
mV resolution.
The temperature Tin °C is obtained by measuring with a multimeter the output volt-
age Vout Temp (difference of potential between +Vout Temp and SGND) and apply-
ing the following formula:
T= (100 x Vout Temp) - 40
For example, supposing to read a voltage Vout Temp = 0.532 V, from the previous
formula we obtain that the radiometer internal temperature is:
T = (100 x 0.532) - 40 = 13.2 °C
Notes on the radiometer calibration:
The calibration factor of the radiometer is factory-determined by measuring the out-
put signal when the radiometer is hit by a parallel and homogeneous beam of light
over the entire surface of the diffuser. Calibration is performed with monochromatic
light at 304 nm.
Currently no international calibration standards for this type of radiometer exist;
therefore, the calibration coefficient only makes sense if the procedure followed to ob-
tain it has been specified. The user has to consider that the same radiometer calibrat-
ed with different procedures can have different sensitivity factors, as explained in the
article "Source of Error in UV Radiation Measurements", T. C. Larason, C. L. Cromer
issued in the "Journal of Research of the National Institute of Standards and Technol-
ogy" Vol. 106, Num. 4, 2001 (The article is available free of charge on the NIST web
site at the following address: https://nvlpubs.nist.gov/nistpubs/jres/106/4/j64lar.pdf).

LPUVB02 -10 -V2.0
6MAINTENANCE
In order to grant measurements high accuracy, it is important to keep the glass dome
clean. Consequently, the more the dome will be kept clean, the more measurements
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.
Because of the high temperature changes between day and night, some condensation
might appear on the radiometer dome. In this case the performed reading is highly
over-estimated. To minimize the condensation, the radiometer is provided with a car-
tridge containing dessicant material (silica-gel). The efficiency of the silica-gel crystals
decreases over time while absorbing humidity. Silica-gel crystals are efficient when
their color is yellow, while they turn white/translucent as soon as they lose their
efficiency. Read instructions at chapter 3 about how to replace the silica-gel crystals.
Silica-gel typical lifetime goes from 2 to 6 months depending on the environment
where the radiometer works.
To exploit all the radiometer features, it is highly recommended that the calibration be
checked annually.

LPUVB02 -11 -V2.0
7TECHNICAL SPECIFICATIONS
UV MEASUREMENT
Typical sensitivity 0.5 – 1.5 V/(W/m2)
Response time <0.5 sec (95%)
Min. load impedance 10 KΩ
Measurement range 0 - 2 W/m2
Viewing range 2πsr
Spectral range 304 nm Peak ±1 nm
302.5 nm…307.5 nm (1/2)
301 nm…309 nm (1/10)
297.5 nm…311.75 nm (1/100)
292.5 nm…316.255 nm (1/1000)
Working temperature -40 °C…+60 °C
Response according to the cosine law: < 8 % (between 0° and 80°)
Long term instability (1 year) <±3%
Non linearity <1%
Response according to temperature < 0.01%/°C
TEMPERATURE MEASUREMENT
Measurement range -40 °C…+60 °C
Accuracy ±0.2 °C
Min. load impedance 10 KΩ
POWER SUPPLY
V+ 7…30 Vdc
Typical consumption 3 mA
Weight 0.90 Kg

LPUVB02 -12 -V2.0
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.

LPUVB02 -13 -V2.0
9ACCESSORIES ORDERING CODES
LPUVB02 Amplified radiometric probe for outdoor use for measuring IRRA-
DIANCE in the UVB spectral range. Supplied with shade disk, syli-
ca-gel cartridge, 2 spare sachets, bubble level, 8-pole M12 con-
nector and Calibration Report.
Accessories
CPM12AA8U… 8-pole cable. 8-pole M12 connector on one end, open wires on
the other end. Available length 2 m (CPM12AA8U.2), 5 m
(CPM12AA8U.5) or 10 m (CPM12AA8U.10).
LPS1 Only attachment bracket, suitable for mast with diameter 40…50
mm. Installation on horizontal or vertical mast.
LPSP1 Spare shade disk.
LPSG Cartridge to contain desiccant silica-gel crystals, complete with O-
ring and cap. Spare part.
LPG Pack of 5 sachets of silica-gel crystals. Spare part.
LPS6 Kit for the installation of the radiometer. The kit includes: 750
mm mast, base fitting, graduated support plate, bracket for radi-
ometer.
LPRING02 Base with levelling device and adjustable holder for mounting the
radiometer in an inclined position.
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.

LPUVB02 -14 -V2.0
NOTE

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.
V2.0
06/2022