LI-COR LI-192 User manual

Underwater
Quantum Sensors
Instruction Manual
LI-192 Underwater Quantum Sensor
LI-193 Spherical Quantum Sensor

Underwater Quantum Sensors
Instruction Manual
LI-COR Biosciences
4647 Superior Street
Lincoln, Nebraska 68504
Phone: [phone]
Toll free: 800-447-3576 (U.S. and Canada)
[email protected]
Regional Offices
LI-COR Biosciences GmbH
Siemensstraße 25A
61352 Bad Homburg
Germany
Phone: [phone]
[email protected]
LI-COR Biosciences UK Ltd.
St. John’s Innovation Centre
Cowley Road
Cambridge
CB4 0WS
United Kingdom
Phone: [phone]
[email protected]
LI-COR Distributor Network:
www.licor.com/envdistributors

NOTICE
The information contained in this document is subject to change without notice.
LI-COR® MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT
LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE. LI-COR shall not be liable for errors contained herein or for incidental or consequential damages in con-
nection with the furnishing, performance, or use of this material.
This document contains proprietary information which is protected by copyright. All rights are reserved. No part of this
document may be may be reproduced or translated into another language with prior written consent of LI-COR, Inc.
All other trademarks or registered trademarks are property of their respective owners.
Copyright © 2006 - 2021, LI-COR, Inc. All rights reservee.
Publication Number: 984-08307
Created on Monday, November 8, 2021
CE Marking:
This product is a CE-marked product. For conformity information, contact LI-COR Support at [email protected]. Out-
side of the U.S., contact your local sales office or distributor.
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device
may not cause harmful interference, and (2) this device must accept any interference received, including interference that
may cause undesired operation.
Printing History
New editions of this manual will include all updates. An update addendum may be used between editions to provide up-
to-date information. Revisions are indicated by the revision number. Minor updates, which do not alter the meaning of
the content, will be incorporated without affecting the revision number.
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iii
Contents
Section 1. General information
Sensor recalibration 1-2
Getting started 1-2
Relationship between the Calibration Constant and Calibration Multiplier 1-2
Connecting to metering devices from other manufacturers 1-3
Using the 2009S Lowering Frame 1-4
Section 2. Factory calibration procedures
Section 3. Using the quantum sensors
LI-192 Underwater Quantum Sensor 3-1
Immersion effect 3-2
Cosine response 3-2
Cosine correction properties 3-3
Spectral response 3-4
LI-193 Spherical Quantum Sensor 3-5
Immersion effect 3-5
Angular response 3-6
Azimuth response 3-6
Spectral response 3-6
Errors 3-7
Mathematical definitions 3-7
Section 4. Cleaning and maintenance
Section 5. Accessories
2222UWB Underwater Cable 5-1
2009S Lowering Frame 5-1
100L Lubricant 5-1
Millivolt Adapters 5-2
2291 Millivolt Adapter 5-2

Section 6. Bibliography
Appendix A. Specifications
Appendix B. Warranty
iv

Section 1.
General information
The LI-192SA and LI-193SA underwater quantum sensors have a coaxial cable that
terminates with a BNC connector. The 2222UWB Underwater Cables used with
LI-COR underwater sensors are terminated with this type of connector, which
allows for direct connection to the LI-250A Light Meter or the LI-1500 Light Sensor
Logger. Figure 1-1 below shows an LI-193SA sensor with the coaxial connector.
This connector also allows the sensor to be used with older (discontinued) instru-
ments, including the LI-189 Quantum/Radiometer/Photometer, LI-250 Light Meter,
the two current channels of the LI-1000 Datalogger, or with older LI-COR integ-
rators.
Figure 1-1. "SA" type sensors are terminated with only a BNC connector on the end of the
coaxial cable.
When a LI-COR Light Meter or data logger is not used, type SA sensors can be used
with other millivolt recorders or data loggers by connecting a millivolt output con-
version adapter. See Accessories on page5-1 for more information. Note that all
LI-COR underwater sensors produce a current signal, not voltage.
1-1LI-192 and LI-193 Quantum Sensors

Section 1. General information
Sensor recalibration
Factory recalibration of LI-COR radiation sensors is recommended every two years.
Sensors can be returned to LI-COR for this service – please contact our technical sup-
port staff for more information.
Getting started
All LI-COR radiation sensors produce a current proportional to the radiation intens-
ity. During factory calibration, sensor output (in microamps) is measured while the
sensor is exposed to a standard lamp of known intensity. The sensor output at this
intensity has general units of microamps per radiation unit and is called the Cal-
ibration Constant (Calconstant). Each sensor has a slightly different output at a
given radiation intensity and will therefore have a unique Calconstant.
Relationship between the Calibration Constant and Calibration
Multiplier
LI-COR Light Meters and dataloggers measure the current output of the sensor in
units of microamps, and convert the measured current to units of radiation. To
make this conversion, LI-COR instruments use the sensor Calibration Multiplier. The
Calibration Multiplier is the negative reciprocal of the Calconstant.
1-1
The LI-192 and LI-193 calibration certificates contain calibration multipliers for both
in air and in water operation. The in water multiplier includes an immersion effect
correction.
To use a type SA sensor with the LI-250, the calibration multiplier is entered in con-
figuration mode, using the up and down arrow keys to scroll the multiplier value(s).
When using the LI-1400 DataLogger, the calibration multiplier must be entered into
the software as described in the Instruction Manual.
When a LI-COR light meter or data logger is not used, your sensor can be used with
other millivolt recorders or data loggers by connecting a millivolt adapter. The LI-
192SA and LI-193SA underwater sensors require the 2291 Millivolt Adapter, which
has a resistance of 1210 Ohms.
1-2 LI-192 and LI-193 Quantum Sensors

The millivolt adapter connects to the BNC connector of the sensor, and the wire
leads of the adapter are connected to the data logger. Sensor output (in millivolts)
when using the millivolt adapter can be computed using "Ohm's Law" (Voltage =
Current × Resistance).
Example: Calculate the millivolt output of an LI-192 Underwater Quantum Sensor
which has a calibration constant of 8.0 μA/1000 μmol s-1 m-2. Assume the 2290 mil-
livolt adapter is used with the sensor.
1-2
The multiplier to use in your data acquisition system is the reciprocal of this result.
For example,
1-3
If the calibration constant for your sensor has been lost or misplaced, it can be
obtained from LI-COR by providing the serial number of the sensor.
Important: When using the sensor under water, the "in water" calibration con-
stant should be used to calculate the millivolt output of the sensor. The "in water"
sensor calibration includes an immersion effect correction.
Connecting to metering devices from other manufacturers
The use of the millivolt adapter with a recorder or data logger other than LI-COR
instruments is often acceptable for radiation levels down to 10% of full sunlight.
Below 10%, the recorder must be very sensitive to pick up the small voltage signal.
The recorder should have a high impedance input (>1 megaohm, such as poten-
tiometric types), and the range adjustment should be 0 - 10 mV, or a more sensitive
range. For low light levels, the sensor should be connected directly to a LI-COR
readout device (without using the millivolt adapter).
In LI-COR underwater cables the inner white wire is positive and the black wire is
negative. The center pin of the BNC connector has a negative signal. This is done
because the trans-impedance amplifier used in LI-COR light meters requires a neg-
ative signal.
Section 1. General information
1-3Connecting to metering devices from other manufacturers

Section 1. General information
For data logger or millivolt applications where the millivolt adapter is needed, the
positive (green) lead should be connected to the low impedance (common terminal)
when plus or minus signal capability is available on the data logger or recorder. This
will minimize noise.
If plus or minus capability is not available on the data logger or recorder, the green
lead should be connected to the positive input and the blue lead to the negative
input. If noise difficulties are encountered, consult LI-COR for special wiring instruc-
tions.
Using the 2009S Lowering Frame
It is recommended that the LI-COR 2009S Lowering Frame (or equivalent) be used
with the sensor for underwater applications.
Important: Do not use LI-COR 2222UWB Underwater Cable to support the
sensor and lowering frame, as damage to the cable can result. An auxiliary cable
should be used to support the lowering frame and sensor. In addition, the
2222UWB cable should not be bent sharply near the sensor.
Note: For cable lengths over 75 m (225 ft.), care should be exercised in its use
since movement of the cable within the water can cause excessive signal noise.
The 2009S Lowering Frame provides for the placement of two cosine sensors, one
each for upwelling and downwelling radiation, or a single underwater spherical
sensor (Figure 1-2 on the facing page). Each LI-COR underwater sensor has three 6-
32 tapped mounting holes on the underside of the sensor for connection to the
mounting ring. Corrosion resistant mounting screws are included with each sensor.
A replacement screw and insulating washer kit is available from LI-COR (p/n 9901-
220).
1-4 LI-192 and LI-193 Quantum Sensors