Apogee Instruments SQ-500 User manual

APOGEE INSTRUMENTS, INC. | 721 WEST 1800 NORTH, LOGAN, UTAH 84321, USA
TEL: [phone] | FAX: [phone] | WEB: APOGEEINSTRUMENTS.COM
Copyright © 2020 Apogee Instruments, Inc.
OWNER’S MANUAL
QUANTUM SENSOR
Model SQ-500
(including SS model, formerly gold)

TABLE OF CONTENTS
Owner’s Manual ............................................................................................................................................................................... 1
Certificate of Compliance......................................................................................................................................................... 3
Introduction ............................................................................................................................................................................. 4
Sensor Models ......................................................................................................................................................................... 5
Specifications ........................................................................................................................................................................... 6
Deployment and Installation.................................................................................................................................................... 9
Cable Connectors................................................................................................................................................................... 10
Operation and Measurement ................................................................................................................................................ 11
Maintenance and Recalibration............................................................................................................................................. 17
Troubleshooting and Customer Support................................................................................................................................ 19
Return and Warranty Policy................................................................................................................................................... 20

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: SQ-500
Type: Quantum Sensor
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
2015/863/EU Amending Annex II to Directive 2011/65/EU (RoHS 3)
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 lead (see
note below), mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), polybrominated
diphenyls (PBDE), bis(2-ethylhexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), dibutyl phthalate (DBP), and
diisobutyl phthalate (DIBP). However, please note that articles containing greater than 0.1% lead concentration are
RoHS 3 compliant using exemption 6c.
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, April 2020
Bruce Bugbee
President
Apogee Instruments, Inc.

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 almost universally quantified as photosynthetic photon flux
density (PPFD), the sum of photons from 400 to 700 nm in units of micromoles per square meter per second (µmol
m-2 s-1, equal to microEinsteins m-2 s-1). While microEinsteins and micromoles are equal (one Einstein = one mole of
photons), the Einstein is not an SI unit, so expressing PPFD as µmol m-2 s-1 is preferred. Daily total PPFD is typically
reported in units of moles of photons per square meter per day (mol m-2 d-1) and is often called daily light integral
(DLI).
The acronym PPF is also used and refers to the photosynthetic photon flux. The acronyms PPF and PPFD refer to
the same variable. Both terms are used because there is not a universal definition of the term flux. Flux is
sometimes defined as per unit area per unit time and sometimes defined as per unit time only. PPFD is used in this
manual.
Sensors that measure PPFD 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 measurement of incident PPFD on plant canopies in outdoor
environments or in greenhouses and growth chambers, and reflected or under-canopy (transmitted) PPFD
measurement in the same environments.
Apogee Instruments SQ-500 series quantum sensors consist of a cast acrylic diffuser (filter), interference filter,
photodiode, and signal processing circuitry mounted in an anodized aluminum housing, and a cable to connect the
sensor to a measurement device. SQ-500 series quantum sensors are designed for continuous PPFD measurement
in indoor or outdoor environments. The SQ-500 model quantum sensor outputs a voltage that is directly
proportional to PPFD. The voltage output by 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.

SENSOR MODELS
This manual covers the unamplified analog output quantum sensor, model SQ-500 (listed in bold below).
Additional models are covered in their respective manuals.
Model
Signal
SQ-500
0-40 mV
SQ-512
0-2.5 V
SQ-515
0-5 V
SQ-520
USB
SQ-521
SDI-12
SQ-522
Modbus
Sensor model number and serial number are
located near the pigtail leads on the sensor cable.
If the manufacturing date of a specific sensor is
required, please contact Apogee Instruments
with the serial number of the sensor.