Apogee SP-422 User manual

APOGEE INSTRUMENTS, INC. | 721 WEST 1800 NORTH, LOGAN, UTAH 84321, USA
TEL: [phone] | FAX: [phone] | WEB: APOGEEINSTRUMENTS.COM
Copyright © 2016 Apogee Instruments, Inc.
OWNER’S MANUAL
USB PYRANOMETER
Models SP-422

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TABLE OF CONTENTS
Owner’s Manual ................................................................................................................................................................................................................ 1
Certificate of Compliance .................................................................................................................................................................................... 3
Introduction............................................................................................................................................................................................................. 4
Sensor Models ......................................................................................................................................................................................................... 5
Specifications........................................................................................................................................................................................................... 6
Deployment and Installation.............................................................................................................................................................................. 9
Software Installation............................................................................................................................................................................................10
Operation and Measurement...........................................................................................................................................................................11
Windows Software ...............................................................................................................................................................................................13
MAC software ........................................................................................................................................................................................................18
Maintenance and Recalibration.......................................................................................................................................................................24
Troubleshooting and Customer Support......................................................................................................................................................26
Return and Warranty Policy ..............................................................................................................................................................................27

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CERTIFICATE OF COMPLIANCE
EU Declaration of Conformity
This declaration of conformity is issued under the sole responsibility of the manufacturer:
Apogee Instruments, Inc.
721 W 1800 N
Logan, Utah 84321
USA
for the following product(s):
Models: SP-422
Type: Pyranometer
The object of the declaration described above is in conformity with the relevant Union harmonization legislation:
2014/30/EU Electromagnetic Compatibility (EMC) Directive
2011/65/EU Restriction of Hazardous Substances (RoHS 2) Directive
Standards referenced during compliance assessment:
EN 61326-1:2013 Electrical equipment for measurement, control and laboratory use – EMC requirements
EN 50581:2012 Technical documentation for the assessment of electrical and electronic products with respect to the
restriction of hazardous substances
Please be advised that based on the information available to us from our raw material suppliers, the products manufactured
by us do not contain, as intentional additives, any of the restricted materials including cadmium, hexavalent chromium, lead,
mercury, polybrominated biphenyls (PBB), polybrominated diphenyls (PBDE).
Further note that Apogee Instruments does not specifically run any analysis on our raw materials or end products for the
presence of these substances, but rely on the information provided to us by our material suppliers.
Signed for and on behalf of:
Apogee Instruments, May 2016
Bruce Bugbee
President
Apogee Instruments, Inc.

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INTRODUCTION
Solar radiation at Earth’s surface is typically defined as total radiation across a wavelength range of 280 to 4000 nm
(shortwave radiation). Total solar radiation, direct beam and diffuse, incident on a horizontal surface is defined as global
shortwave radiation, or shortwave irradiance (incident radiant flux), and is expressed in Watts per square meter (W m-2, equal
to Joules per second per square meter).
Pyranometers are sensors that measure global shortwave radiation. Apogee SP series pyranometers are silicon-cell
pyranometers, and are only sensitive to a portion of the solar spectrum, approximately 350-1100 nm (approximately 80 % of
total shortwave radiation is within this range). However, silicon-cell pyranometers are calibrated to estimate total shortwave
radiation across the entire solar spectrum. Silicon-cell pyranometer specifications compare favorably to specifications for
World Meteorological Organization (WMO) moderate and good quality classifications and specifications for International
Organization of Standardization (ISO) second class and first class classifications, but because of limited spectral sensitivity,
they do not meet the spectral specification necessary for WMO or ISO certification.
Typical applications of silicon-cell pyranometers include incoming shortwave radiation measurement in agricultural,
ecological, and hydrological weather networks, and solar panel arrays.
Apogee Instruments SP series pyranometers consist of a cast acrylic diffuser (filter), photodiode, and signal processing
circuitry mounted in an anodized aluminum housing, and a cable to connect the sensor to a measurement device. Sensors
are potted solid with no internal air space and are designed for continuous total shortwave radiation measurement on a
planar surface in outdoor environments. SP series sensors output an analog voltage that is directly proportional to total
shortwave radiation from the sun. The voltage signal from the sensor is directly proportional to radiation incident on a planar
surface (does not have to be horizontal), where the radiation emanates from all angles of a hemisphere.

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SENSOR MODELS
This manual covers the USB smart sensor model SP-422. For additional models see manuals SP-110/SP-230, SP-212/SP-215,
and SP-214.
Model
Signal
SP-422 USB
SP-110 Self-powered
SP-230* Self-powered
SP-212 0-2.5 V
SP-214 4-20 mA
SP-215 0-5 V
Sensor model number, serial number, production date,
and calibration factor are located near the pigtail leads on
the sensor cable.

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SPECIFICATIONS
Calibration Traceability
Apogee Instruments SP series pyranometers are calibrated through side-by-side comparison to the mean of four Apogee
model SP-110 transfer standard pyranometers (shortwave radiation reference) under high intensity discharge metal halide
lamps. The transfer standard pyranometers are calibrated through side-by-side comparison to the mean of at least two ISO-
classified reference pyranometers under sunlight (clear sky conditions) in Logan, Utah. Each of four ISO-classified reference
pyranometers are recalibrated on an alternating year schedule (two instruments each year) at the National Renewable
Energy Laboratory (NREL) in Golden, Colorado. NREL reference standards are calibrated to the World Radiometric Reference
(WRR) in Davos, Switzerland.
SP-422
Resolution 0.1 W m-2
Calibration Factor Custom for each sensor and stored in firmware
Calibration Uncertainty ± 5 % (see Calibration Traceability below)
Measurement Repeatability Less than 1 %
Long-term Drift
(Non-stability)
Less than 2 % per year
Non-linearity Less than 1 % (up to 1750 W m-2)
Response Time Software updates every second
Field of View 180º
Spectral Range
360 to 1120 nm (wavelengths where response is 10 % of maximum;
see Spectral Response below)
Directional (Cosine) Response ± 5 % at 75º zenith angle (see Cosine Response below)
Temperature Response 0.04 ± 0.04 % per C (see Temperature Response below)
Operating Environment
-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths
of 30 m
Dimensions 24 mm diameter, 28 mm height
Mass Sensor head weighs 90 g
USB Cable 4.6 m (15 ft)
Current Draw (when Logging) 2.1 mA

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Spectral Response
Temperature Response
Mean temperature response of four Apogee
silicon-cell pyranometers. Temperature response
measurements were made at approximately 10 C
intervals across a temperature range of
approximately -10 to 50 C under sunlight. Each
pyranometer had an internal thermistor to
measure temperature. At each temperature set
point, a reference blackbody pyranometer was
used to measure solar intensity.
Spectral response estimate of Apogee silicon-cell
pyranometers. Spectral response was estimated
by multiplying the spectral response of the
photodiode, diffuser, and adhesive. Spectral
response measurements of diffuser and adhesive
were made with a spectrometer, and spectral
response data for the photodiode were obtained
from the manufacturer.

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Cosine Response
Mean cosine response of eleven Apogee silicon-
cell pyranometers (error bars represent two
standard deviations above and below mean).
Cosine response measurements were made
during broadband outdoor radiometer
calibrations (BORCAL) performed during two
different years at the National Renewable Energy
Laboratory (NREL) in Golden, Colorado. Cosine
response was calculated as the relative difference
of pyranometer sensitivity at each solar zenith
angle to sensitivity at 45° solar zenith angle. The
blue symbols are AM measurements, the red
symbols are PM measurements.
Directional, or cosine, response is defined as
the measurement error at a specific angle of
radiation incidence. Error for Apogee silicon-
cell pyranometers is approximately ± 2 % and
± 5 % at solar zenith angles of 45° and 75°,
respectively.

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DEPLOYMENT AND INSTALLATION
Mount the sensor to a solid surface with the nylon mounting screw provided. To accurately measure total shortwave
radiation incident on a horizontal surface, the sensor must be level. An Apogee Instruments model AL-100 leveling plate is
recommended for this purpose. To facilitate mounting on a cross arm, an Apogee Instruments model AM-110 mounting
bracket is recommended.
To minimize azimuth error, the sensor should be mounted with the cable pointing toward true north in the northern
hemisphere or true south in the southern hemisphere. Azimuth error is typically less than 1 %, but it is easy to minimize by
proper cable orientation.
In addition to orienting the cable to point toward the nearest pole, the sensor should also be mounted such that
obstructions (e.g., weather station tripod/tower or other instrumentation) do not shade the sensor. Once mounted, the
green cap should be removed from the sensor. The green cap can be used as a protective covering for the sensor when it
is not in use.
Nylon Screw: 10-32x3/8
Model AL-100

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SOFTWARE INSTALLATION
Installing the software on a PC
1. Double click on the installer package:
2. On the ‘Welcome’ screen, please click ‘Next’ to continue.
3. Select the radio button next to “I Agree” to the UELA… and click ‘Next’ to continue.
4. On the ‘Ready to Install the Program’ screen, click ‘Install’ to continue.
5. Click ‘Finish’ to complete the installation. There are shortcuts on your desktop and in your start bar.
Installing the software on a Mac
The software will automatically download.

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OPERATION AND MEASUREMENT
Spectral Errors for Measurements with Silicon-cell Pyranometers
Apogee SP series pyranometers are calibrated under electric lamps in a calibration laboratory. The calibration procedure
simulates calibration under clear sky conditions at a solar zenith angle of approximately 45°. However, due to the limited
spectral sensitivity of silicon-cell pyranometers compared to the solar radiation spectrum (see graph below), spectral errors
occur when measurements are made in conditions that differ from conditions the sensor was calibrated under (e.g., the solar
spectrum differs in clear sky and cloudy conditions, thus measurements in cloudy conditions result in spectral error because
sensors are calibrated in clear sky conditions).
Silicon-cell pyranometers can still be used to measure shortwave radiation in conditions other than clear sky or from
radiation sources other than incoming sunlight, but spectral errors occur when measuring radiation with silicon-cell
pyranometers in these conditions. The graphs below show spectral error estimates for Apogee silicon-cell pyranometers at
varying solar zenith angles and varying atmospheric air mass. The diffuser is optimized to minimize directional errors, thus
the cosine response graph in the Specifications section shows the actual directional errors in practice (which includes
contributions from the spectral shift that occurs as solar zenith angle and atmospheric air mass change with time of day and
time of year). The table below provides spectral error estimates for shortwave radiation measurements from shortwave
radiation sources other than clear sky solar radiation.
Spectral response of Apogee SP series
pyranometers compared to solar radiation
spectrum at Earth’s surface. Silicon-cell
pyranometers, such as Apogee SP series, are
only sensitive to the wavelength range of
approximately 350-1100 nm, and are not
equally sensitive to all wavelengths within
this range. As a result, when the spectral
content of solar radiation is significantly
different than the spectrum that silicon-cell
pyranometers were calibrated to, spectral
errors result.

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Spectral error for Apogee SP series
pyranometers as a function of atmospheric
air mass, assuming calibration at an air mass
of 1.5.
Spectral error for Apogee SP series
pyranometers as a function of solar zenith
angle, assuming calibration at a zenith
angle of 45°.

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WINDOWS SOFTWARE
When the SP-422 sensor is not plugged into the USB port, the software
will display a message in the lower left corner, “Device Not
Connected,” indicating it cannot establish communication with the
sensor.
Plug the sensor into a USB port and allow some time for the sensor
to automatically establish communication with the software. Once
established, the message in the lower left corner will display
“Device Connected SN: ####” and real-time shortwave radiation
readings will update on the screen. Moving the sensor closer to a
light source should increase the readings, while blocking all light
from the sensor should drop the reading to zero.

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Clicking ‘Calibration’ will display the factory calibrated multiplier
and offset values. These values are saved in firmware and can be
recovered by clicking the ‘Recover Original’ button. Deriving a new
calibration multiplier and offset is accomplished by clicking the
‘Recalibrate’ button. This is applicable if users want to calibrate the
sensor to their own specific light source. Note that a reference
value of the light source is required to complete a recalibration.
After clicking the ‘Recalibate’ button the user will be prompted to
cover the sensor. Place a dark cap over the sensor and wait for the
real-time shortwave readiation reading to settle at zero. Click OK.
Click the ‘Settings’ icon to display the software options. Note
‘Light Source’ is not a setting for the SP-422.

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Uncover the sensor and wait for the shortwave radiation reading to
settle before entering the reference value. Click OK.
The multiplier and offset values will automatically calculate and
update in the appropriate field. Be sure to click ‘Save’ to retain the
new multiplier and offset.
Clicking ‘Data Logging’ will allow the user to log interval
measurements in a csv file while the software is open and
communicating with the sensor.
Click ‘Setup’ and the Setup Logging window appears. Click the
‘Browse’ button to create or select a csv file.
Select the desired sampling interval. Note that 1 second is the
minimum interval allowed. Click ‘Start’.

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The data logging window will start to update at the specified
sampling interval and display the Timestamp and Data Value. At the
same time, data will be written to the csv file. Note that if the csv file is
open in another program new data will not be saved to it.
The data logging window can be closed without affecting logged
data by clicking the ‘Exit’ button. The ‘Stop’ button must be clicked to
end data logging.
The about screen tells you the software and firmware versions. These
can be used to help troubleshoot if problems arise.
‘Manage Field Logging’ is used to setup the SP-422 for use in the
field. When the SP-422 is supplied power from a USB power source it
will log data which you can retrieve. Choose the interval that data is
saved as well as the interval that data is sampled and the light source
used. The shortest sampling interval is 1 second. The longest
sampling or logging interval is 1440 minutes (1 day). Click ‘Load
Settings’ to see current settings and ‘Save Settings’ to save the
settings you want to the sensor. Note: If you don’t click save the
sensor won’t change the settings.

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Set the sampling interval in minutes or seconds. The sampling interval
is how often a measurement is taken and logging interval is how often
the data is saved. The logged data is the average of the samples. The
logging interval must be evenly divided by the sampling interval. For
example if the logging interval is 5 minutes and the sampling interval is
2 minutes it causes an error. But a sampling interval of 1 minute is
acceptable.
Before clicking ‘Get Logged Data’ it is important to set the time of the
last logged data point. This is used to back calculate the timestamps for
the remaining data points. If you just unplugged the sensor and
plugged it into the computer the preloaded day and time should be
sufficient.
Click ‘Get Logged Data’ to save the data to your computer. You will be
asked where you want to save the data.
Click ‘Erase Data’ to erase all the saved data. This can’t be undone.
To use additional SP-422 devices, open additional ApogeeConnect software windows. The device serial number will display in the lower
left hand corner of the corresponding software window. Devices may be selected by serial number in the tool bar.

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MAC SOFTWARE
When the SP-422 sensor is not plugged into the USB port, the software
will display a message in the lower left corner, “Device Not
Connected,” indicating it cannot establish communication with the
sensor.
Plug the sensor into a USB port and allow some time for the sensor
to automatically establish communication with the software. Once
established, the message in the lower left corner will display
“Device Connected Model: SN ####” and real-time shortwave
radiation readings will update on the screen. Moving the sensor
closer to a light source should increase the readings, while blocking
all light from the sensor should drop the reading to zero.

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Click the ‘Settings’ icon to display the software options. Note ‘Light
Source’ is not a setting option for the SP-422.
Clicking ‘Calibration’will display the factory calibrated multiplier
and offset values. These values are saved in firmware and can be
recovered by clicking the ‘Recover Original’ button. Deriving a new
calibration multiplier and offset is accomplished by clicking the
‘Recalibrate’ button. This is applicable if users want to calibrate the
sensor to their own specific light source. Note that a reference
value of the light source is required to complete a recalibration.
After clicking the ‘Recalibrate’ button the user will be prompted to
cover the sensor. Place a dark cap over the sensor and wait for the
real-time shortwave radiation reading to settle at zero. Click OK.
Uncover the sensor and wait for the shortwave radiation reading to
settle before entering the reference value. Click OK.

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The multiplier and offset values will automatically calculate and
update in the appropriate field. Be sure to click ‘Save’ to retain the
new multiplier and offset.
Clicking ‘Data Logging’will allow the user to log interval
measurements in a csv file while the software is open and
communicating with the sensor.
Click ‘Setup’ and the Setup Logging window appears. Click the
‘Browse button to create or select a csv file.
Select the desired sampling interval. Note that 1 second is the
minimum interval allowed. Click ‘Start’.