Apogee SQ-100 Series User manual

APOGEE INSTRUMENTS, INC. 721 WEST 1800 NORTH, LOGAN, UTAH 84321, USA
TEL: [phone] FAX: [phone] WEB: APOGEEINSTRUMENTS.COM
Copyright © 2013 Apogee Instruments, Inc.
OWNER’S MANUAL
QUANTUM SENSOR
Model SQ-100 and SQ-300 Series
Turfschipper 114 | 2292 JB Wateringen | Tel. [phone] | Fax. [phone] | [email protected] | www.catec.nl Turfschipper 114 | 2292 JB Wateringen | Tel. [phone] | Fax. [phone] | [email protected] | www.catec.nl
M E E T I N S T R U M E N T A T I E

2
TABLE OF CONTENTS
DECLARATION OF CONFORMITY……………………………..……………………. 3
INTRODUCTION…………………………………………………………………………….. 4
SENSOR MODELS....................................................................... 5
SPECIFICATIONS……………………………………………………………………………. 6
DEPLOYMENT AND INSTALLATION……………………………………………….. 9
OPERATION AND MEASUREMENT……………………………………..…………. 10
MAINTENANCE AND RECALIBRATION………………………………….......... 13
TROUBLESHOOTING AND CUSTOMER SUPPORT…………………………… 15
RETURN POLICY AND WARRANTY…………………………………………………. 16

3
DECLARATION OF CONFORMITY
CE and ROHS Certificate of Compliance
We Apogee Instruments, Inc.
721 W 1800 N
Logan, Utah 84321
USA
Declare under our sole responsibility that the products:
Models: SQ-110, SQ-120, SQ-311, SQ-321, SQ-313, SQ-323, SQ-316, SQ-326
Type: Quantum Sensor
are in conformity with the following standards and relevant EC directives:
Emissions: EN 61326-1:2013
Immunity: EN 61326-1:2013
Safety: EN 61010-1:2010
EU directive 2004/108/EC, EMC
EU directive 2002/95/EC, RoHS (Restriction of Hazardous Substances)
EU directive 2011/65/EU, RoHS2
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.
Bruce Bugbee
President
Apogee Instruments, Inc.
June 2013

4
INTRODUCTION
Radiation that drives photosynthesis is called photosynthetically active radiation (PAR) and is typically
defined as total radiation across a range of 400 to 700 nm. PAR is often expressed as photosynthetic
photon flux (PPF): photon flux in units of micromoles per square meter per second (µmol m-2 s-1, equal to
microEinsteins per square meter per second) summed from 400 to 700 nm (total number of photons from
400 to 700 nm). While Einsteins and micromoles are equal (one Einstein = one mole of photons), the
Einstein is not an SI unit, so expressing PPF as µmol m-2 s-1 is preferred.
Sensors that measure PPF are often called quantum sensors due to the quantized nature of radiation. A
quantum refers to the minimum quantity of radiation, one photon, involved in physical interactions (e.g.,
absorption by photosynthetic pigments). In other words, one photon is a single quantum of radiation.
Typical applications of quantum sensors include incoming PPF measurement over plant canopies in
outdoor environments or in greenhouses and growth chambers, and reflected or under-canopy
(transmitted) PPF measurement in the same environments.
Apogee Instruments SQ series quantum sensors 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 PPF measurement in indoor or outdoor environments. SQ series sensors output an analog
voltage that is directly proportional to PPF under sunlight (e.g., model SQ-110) or electric lights (e.g.,
model SQ-120). 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.

5
SENSOR MODELS
Apogee SQ series quantum sensor models covered in this manual are un-amplified versions, SQ-100
series and SQ-300 series. Amplified models are also available, which provide larger voltage signals; see
manual for SQ-200 series quantum sensors.
Line quantum sensors, SQ-300 series, provide spatially averaged PPF measurements. All sensors along
the length of the line are connected in parallel, and as a result, Apogee line quantum sensors output a
single voltage signal that is directly proportional to PPF averaged from the location of the individual
sensors.
Sensor model number, serial number, production
date, and calibration factor are located near the
pigtail leads on the sensor cable.

6
SPECIFICATIONS
Sensitivity:
0.2 mV per µmol m-2 s-1
Calibration Factor:
5.0 µmol m-2 s-1 per mV (reciprocal of sensitivity)
Calibration Uncertainty:
± 5 % (see Calibration Traceability below)
Measurement Repeatability:
< 1 %
Non-stability (Long-term Drift):
< 2 % per year
Non-linearity:
< 1 % (up to 4000 µmol m-2 s-1)
Response Time:
< 1 ms
Field of View:
180o
Spectral Range:
410 nm to 655 nm (wavelengths where response is greater than 50 % of maximum; see
Spectral Response below)
Directional (Cosine) Response:
± 5 % at 75ozenith angle (see Cosine Response below)
Temperature Response:
0.06 ± 0.06 % 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:
SQ-110, -120: 2.4 cm diameter and 2.8 cm height
SQ-313, -316, -323, -326: 50 cm length, 1.5 cm width, 1.5 cm height
SQ-311, -321: 70 cm length, 1.5 cm width, 1.5 cm height
Mass:
SQ-100 series: 90 g (with 5 m of lead wire)
SQ-313, -316, -323, -326: 275 g
SQ-311, -321: 375 g
Cable:
5 m of shielded, twisted-pair wire.
Additional cable available in multiples of 5 m
Santoprene rubber jacket (high water resistance, high UV stability, flexibility in cold conditions)
Pigtail lead wires
Calibration Traceability:
Apogee SQ series quantum sensors are calibrated through side-by-side comparison to the mean of four
Apogee model SQ-110 or SQ-120 transfer standard quantum sensors under high output T5 cool white
fluorescent lamps. The transfer standard quantum sensors are calibrated through side-by-side
comparison to the mean of at least three LI-COR model LI-190 reference quantum sensors under high
output T5 cool white fluorescent lamps. The reference quantum sensors are recalibrated on a biannual

7
schedule with a LI-COR model 1800-02 Optical Radiation Calibrator using a 200 W quartz halogen lamp.
The 1800-02 and quartz halogen lamp are traceable to the National Institute of Standards and
Technology (NIST).
Spectral Response:
Temperature response:
Mean temperature response of eight SQ
series quantum sensors (
errors bars
represent two standard deviations
above and below mean
). Temperature
response measurements were made at 10
C intervals across a temperature range of
approximately -10 to 40 C in a
temperature controlled chamber under a
fixed, broad spectrum, electric lamp. At
each temperature set point, a
spectroradiometer was used to measure
light intensity from the lamp and all
quantum sensors were compared to the
spectroradiometer. The
spectroradiometer was mounted external
to the temperature control chamber and
remained at room temperature during
the experiment.
Mean spectral response of six SQ series
quantum sensors ( error bars represent two
standard deviations above and below
mean
) compared to PPF weighting function.
Spectral response measurements were
made at 10 nm increments across a
wavelength range of 300 to 800 nm in a
monochromator with an attached electric
light source. Measured spectral data from
each quantum sensor were normalized by
the measured spectral response of the
monochromator/electric light combination,
which was measured with a
spectroradiometer.

8
Cosine Response:
Mean cosine response of twenty-three SQ
series quantum sensors (
error bars
represent two standard deviations above
and below mean
). Cosine response
measurements were made by direct side-
by-side comparison to the mean of four
reference thermopile pyranometers, with
solar zenith angle-dependent factors
applied to convert total shortwave
radiation to PPF. Blue points represent the
AM response and red points represent the
PM response.
Directional, or cosine, response is defined
as the measurement error at a specific
angle of radiation incidence. Error for
Apogee SQ series quantum sensors is
approximately ± 2 % and ± 5 % at solar
zenith angles of 45°and 75°, respectively.

9
DEPLOYMENT AND INSTALLATION
Mount the sensor to a solid surface with the nylon mounting screw provided. To accurately measure PPF
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.

10
OPERATION AND MEASUREMENT
Connect the sensor to a measurement device (meter, datalogger, controller) capable of measuring and
displaying or recording a millivolt signal (an input measurement range of approximately 0-500 mV is
required to cover the entire range of PPF from the sun). In order to maximize measurement resolution
and signal-to-noise ratio, the input range of the measurement device should closely match the output
range of the quantum sensor.
DO NOT connect the sensor to a power source. The sensor is self-
powered and applying voltage will damage the sensor.
All Apogee un-amplified quantum sensor models (SQ-100 and SQ-300 series) have a standard PPF
calibration factor of exactly:
5.0 µmol m-2 s-1 per mV
Multiply this calibration factor by the measured mV signal to convert sensor output to PPF in units of µmol
m-2 s-1:
Calibration Factor (5.0 µmol m-2 s-1 per mV) * Sensor Output Signal (mV) = PPF (µmol m-2 s-1)
5.0 * 400 = 2000
Example of PPF measurement with an Apogee quantum
sensor. Full sunlight yields a PPF on a horizontal plane at
the Earth’s surface of approximately 2000 µmol m-2 s-1. This
yields an output signal of 400 mV. The signal is converted to
PPF by multiplying by the calibration factor of 5.00 µmol m-2
s-1 per mV.