LI-COR LI-210SA Manual de usuario
LI-COR Radiation Sensors
Instruction Manual
Terrestrial Type SA:
●LI-190SA Quantum Sensor
●LI-200SA Pyranometer Sensor
●LI-210SA Photometric Sensor
●LI-191SA Line Quantum Sensor
LI-COR Terrestrial Radiation
Sensors, Type SA
Instruction Manual
Publication No. 8609-56 November, 1986
Revised July, 1991
LI-COR, inc.
4421 Superior Street
P.O. Box 4425
Lincoln, NE 68504 USA
Telephone: 402-467-3576
FAX: 402-467-2819
Toll-free 1-800-447-3576 (U.S. & Canada)
© Copyright 1986, LI-COR, Lincoln, Nebraska USA
ii
How to Use this Manual
This manual contains the operation and maintenance information for all
LI-COR terrestrial, type SA sensors.
The first section of the manual contains general information which relates to
all LI-COR terrestrial sensors (i.e. operation, recalibration, etc).
After the general information, specific information is given for each sensor.
When reading through the manual, read the general information first and
then read the specific information for your sensor (i.e. the LI-190SA
Quantum Sensor, LI-200SA Pyranometer Sensor, etc).
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
connection 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 photocopied, reproduced, or translated to another
language without prior written consent of LI-COR, Inc.
© Copyright 1986, LI-COR Inc.
iii
Table of Contents
Section 1. General Information
Type "SA" LI-COR Sensors .................................................................... 5
Sensor Recalibration ................................................................................ 5
Operation .................................................................................................. 6
Cosine Response ...................................................................................... 8
Cosine Correction Properties ................................................................... 8
Cleaning Information ................................................................................ 9
Section 2. LI-190SA Quantum Sensor
Use of the Quantum Sensor ..................................................................... 10
LI-190SA Spectral Response ................................................................... 10
Calibration ................................................................................................ 12
LI-190SA Specifications .......................................................................... 13
Section 3. LI-200SA Pyranometer Sensor
Use of the Pyranometer Sensor ................................................................ 14
LI-200SA Spectral Response ................................................................... 15
Calibration ................................................................................................ 15
LI-200SA Specifications .......................................................................... 17
Section 4. LI-210SA Photometric Sensor
Use of the Photometric Sensor ................................................................ 18
Photometric Terms ................................................................................... 19
Spectral Response .................................................................................... 20
Calibration ................................................................................................ 20
LI-200SA Specifications .......................................................................... 21
iv
Section 5. LI-191SA Line Quantum Sensor
Use of the Line Quantum Sensor ............................................................. 22
Cosine Correction Properties ................................................................... 23
Surface Variation Error ............................................................................ 23
Spectral Response .................................................................................... 23
Absolute Calibration ................................................................................ 24
LI-191SA Specifications .......................................................................... 25
Appendix
References ................................................................................................ 26
Accessories .............................................................................................. 26
Warranty .................................................................................................. 27
List of Figures
Figure 1. "SA" type sensors .................................................................... 5
Figure 2. Lambert's cosine law ............................................................... 8
Figure 3. Cosine response of terrestrial sensors ...................................... 9
Figure 4. LI-190SA spectral response curve .......................................... 11
Figure 5. LI-200SA spectral response curve .......................................... 16
Figure 6. LI-210SA spectral response curve .......................................... 18
Figure 7. LI-191SA cosine response ...................................................... 24
List of Tables
Table 1. Millivolt adapters for "SA" type sensors ................................. 6
5
Section I
General Information
Type "SA" Sensors
LI-COR SA type sensors are characterized by having the coaxial sensor
cable terminated with a BNC connector. Figure 1 shows a typical SA type
sensor.
Type SA terrestrial sensors include the LI-190SA Quantum Sensor, the
LI-191SA Line Quantum Sensor, the LI-200SA Pyranometer Sensor, and
the LI-210SA Photometric sensor. The SA type underwater sensors include
the LI-192SA Underwater Quantum Sensor, and the LI-193SA Underwater
Quantum Sensor.
Figure 1. "SA" type sensors are terminated with only a
BNC connector on the end of the coaxial cable.
Sensor Recalibration
Recalibration of LI-COR radiation sensors is recommended every two
years. Sensors may be returned to LI-COR for recalibration or recalibrated
using the LI-COR 1800-02 Optical Radiation Calibrator (NOTE: the
LI-200SA Pyranometer Sensor and LI-191SA Line Quantum Sensor must
be returned to LI-COR for recalibration).
6
Operation
The sensor cable is terminated with a BNC connector. This connector
allows the sensor to be used with the LI-189 Quantum/Radiometer/
Photometer, the two current channels of the LI-1000 Datalogger, or with
older LI-COR integrators, including the LI-510B and the LI-550B.
To use a type SA sensor with the LI-189 Quantum/Radiometer/Photometer,
the calibration multiplier is entered by using the calibrate keys and dialing
in the calibration multiplier using the calibration screw (see LI-189 manual).
The calibration multiplier is given on the certificate of calibration and on
the sensor calibration tag.
To use type SA sensors with the LI-1000, the calibration constant must be
entered into the LI-1000 in the form of a multiplier. The multiplier (entered
as a1 in the polynomial Y = a0 + a1X + a2X2+ a3X3+ a4X4+ a5X5with
LI-1000 version 2.02 software) is given on the certificate of calibration. For
complete information on configuring the LI-1000 please consult the
LI-1000 Instruction manual.
To use a type SA sensor with LI-COR light meters such as the LI-185B,
LI-188B or LI-1776, a factory installed calibration connector is required.
Other LI-COR light meters and integrators including the LI-170, LI-185,
LI-185A, LI-188, LI-510, and LI-550 require the use of the 9901-014
connector conversion cable. Contact LI-COR for further details.
When a LI-COR Light Meter or data logger is not used, the sensors can be
used with other millivolt recorders or data loggers by connecting a millivolt
adapter. Table 1 lists the millivolt adapters required for each sensor and the
resistance of each adapter.
Table 1. Millivolt adapters for "SA" type sensors.
Sensor Millivolt Adapter Resistance
LI-190SA 2290S 604 Ohm
LI-200SA 2220S 147 Ohm
LI-210SA 2290S 604 Ohm
LI-191SA 2290S604 Ohm
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 "Ohms
Law" (Voltage = Current ×Resistance).
7
Example: Calculate the millivolt output of an LI-190SA Quantum
Sensor which has a calibration constant of 8.0 µA/1000 µmol s-1 m
-2.
Assume the 2290S millivolt adapter is used with the sensor.
8.0 A
1000 mol s m
1 A
10 A 6 Ohm = 0.004832 volts
1000 mol s m
-1 2 6 -1 2
µ
µ×µ×µ
−−
04
Or, = 4.83 mV/1000 µmol s-1 m-2
The shield of the coaxial cable on LI-COR light sensors is positive and the
center conductor is negative. (The trans-impedance amplifier used in
LI-COR light meters requires a negative signal). For data logger or
millivolt applications where the millivolt adapter is used, 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. The negative (blue) lead is connected to the signal input. This
will minimize noise.
If plus or minus capability is not available on the data logger or recorder,
the red lead should be connected to the positive input and the black lead to
the negative input. If noise difficulties are encountered, consult LI-COR for
special wiring instructions.
The BNC connector and millivolt adapter are not weatherproof. If the
millivolt adapter is attached to the sensor for connection to a data logger or
millivolt recorder, this connection should be made at the recorder end
(indoors). This eliminates thermocouple effects caused by exposing the
BNC connector and millivolt adapter to rapidly changing direct solar
radiation. These effects are not noticeable when the connectors are used
indoors out of direct radiation.
If a longer cable is needed for your application, use LI-COR extension cable
(2222SB or 2222SB-100), or coaxial (RG174) cable. Cables ≤700 feet
(213 m) can be used if the signal is not degraded by electrical interference
from electromagnetic fields (i.e., from radio transmitters). If you need to
use a cable longer than 700 feet, use a heavier gauge coaxial cable (i.e.,
RG122). The total DC resistance of the extension cable used with the
LI-200SA must be ≤75Ω. The voltage developed across the sensor's
photodiode should not exceed 20 mV. Calculate the voltage according to
[Total cable resistance + mV adapter resistance (Ω)] ×sensor output (µA) = mV.
If extension cable is used where the BNC termination will be exposed
outdoors or on a conductive surface, the BNC connection should be
insulated by wrapping it with tape. This is done to avoid ground loops.
8
Cosine Response
Measurements intended to approximate radiation impinging upon a flat
surface (not necessarily level) from all angles of a hemisphere are most
accurately obtained with a cosine corrected sensor.
A sensor with a cosine response (follows Lambert's cosine law) allows
measurement of flux densities through a plane surface. This allows the
sensor to measure flux densities per unit area (m2). A sensor without an
accurate cosine correction can give a severe error under diffuse radiation
conditions within a plant canopy, at low solar elevation angles, under
fluorescent lighting, etc.
The cosine relationship can be thought of in terms of radiant flux lines
impinging upon a surface normal to the source (Figure 2A) and at an angle
of 60°from normal (Figure 2B). Figure 2A shows 6 rays striking the unit
area, but at a 60°angle, only 3 rays strike the same unit area. This is
illustrated mathematically as
S = (I) (cosine 60°) per unit area
3 = (6) (0.5) per unit area
where S = vertical component of solar radiation; I = solar radiation
impinging perpendicular to a surface and cosine 60°= 0.5.
Unit
Area
A. B.
Figure 2. Lambert's Cosine Law.
Cosine Correction Properties
Cosine corrected LI-COR terrestrial type sensors are all designed for the
same cosine response characteristics. The percent of true cosine response is
presented in Figure 3. The error is typically less than ±5% for angles less
than 80°from the normal axis of the sensor. At 90°a perfect cosine
collector response would be zero and at that angle any error is infinite.
9
Figure 3. Cosine response of LI-COR terrestrial type sensors.
Cleaning Information
DO NOT use alcohol, organic solvents, abrasives, or strong detergents to
clean the diffusor element on LI-COR light sensors.
The acrylic material used in LI-COR light sensors can be crazed by
exposure to alcohol or organic solvents, which will adversely affect the
cosine response of the sensor.
Clean the sensor only with water and/or a mild detergent such as
dishwashing soap. LI-COR has found that vinegar can also be used to
remove hard water deposits from the diffusor element, if necessary.
Este manual sirve para los siguientes modelos
3
Tabla de contenidos
Otros manuales de Accesorios de LI-COR
LI-COR
LI-COR LI-190R Manual de usuario
LI-COR
LI-COR Stevens Hydra Probe II Manual de usuario
LI-COR
LI-COR LI-192 Manual de usuario
LI-COR
LI-COR LI-190R Manual de usuario
LI-COR
LI-COR LAI-2050 Guía
LI-COR
LI-COR LI-1500 Manual de usuario
LI-COR
LI-COR 1400-101 Manual de usuario
LI-COR
LI-COR LI-192 Manual de usuario
LI-COR
LI-COR LI-190R Manual de usuario
