Campbell CMP6-L User manual

INSTRUCTION MANUAL
CMP6-L, CMP10-L, CMP11-L
and CMP21-L Pyranometers
March 2015
Copyright © 2015
Campbell Scientific (Canada) Corp.

WARRANTY AND ASSISTANCE
This equipment is warranted by CAMPBELL SCIENTIFIC (CANADA) CORP. ("CSC") to
be free from defects in materials and workmanship under normal use and service for
twenty-four (24) months from date of shipment unless specified otherwise. *****
Batteries are not warranted. ***** CSC's obligation under this warranty is limited to
repairing or replacing (at CSC's option) defective products. The customer shall assume
all costs of
removing, reinstalling, and shipping defective products to CSC. CSC will
return such products by surface carrier prepaid. This warranty shall not apply to any
CSC products which have been subjected to modification, misuse, neglect, accidents of
nature, or shipping damage. This warranty is in lieu of all other warranties, expressed or
implied, including warranties of merchantability or fitness for a particular purpose. CSC
is not
liable for special, indirect, incidental, or consequential damages.
Products may not be returned without prior authorization. To obtain a Return
Merchandise Authorization (RMA), contact CAMPBELL SCIENTIFIC (CANADA) CORP.,
at [phone]. An RMA number will be issued in order to facilitate Repair Personnel
in identifying an instrument upon arrival. Please write this number clearly on the outside
of the shipping container. Include description of symptoms and all pertinent details.
CAMPBELL SCIENTIFIC (CANADA) CORP. does not accept collect calls.
Non-warranty products returned for repair should be accompanied by a purchase order to
cover repair costs.

i
Table of Contents
PDF viewers: These page numbers refer to the printed version of this document. Use the
PDF reader bookmarks tab for links to specific sections.
1. Introduction................................................................1
2. Cautionary Statements..............................................1
3. Initial Inspection.........................................................1
3.1 Ships With............................................................................................2
3.2 Calibration Certificate..........................................................................2
4. Quickstart...................................................................2
4.1 Siting....................................................................................................2
4.2 Mounting..............................................................................................3
4.3 Datalogger Programming/Wiring.........................................................5
5. Overview.....................................................................6
5.1 Models .................................................................................................6
5.2 Construction.........................................................................................6
6. Specifications.............................................................7
6.1 Pyranometers........................................................................................7
6.2 CVF3 Ventilation Unit.........................................................................8
6.3 CVF4 Ventilation Unit.........................................................................8
7. Installation..................................................................9
7.1 Mounting to a Tripod or Tower ...........................................................9
7.2 Wiring ................................................................................................12
7.2.1 CMP6, CMP10, CMP11, and CMP21 Thermopile Schematic ...13
7.2.2 CMP6 and CMP11 Wiring..........................................................13
7.2.3 CMP21 Wiring............................................................................14
7.3 Programming......................................................................................15
7.3.1 Solar Radiation Measurement.....................................................15
7.3.1.1 Input Range ......................................................................15
7.3.1.2 Multiplier..........................................................................16
7.3.1.3 Offset................................................................................17
7.3.1.4 Output Format Considerations .........................................17
7.3.2 CMP21 Internal Thermistor Measurement .................................17
7.3.3 Example Programs ......................................................................18
7.3.3.1 CR1000 Example Program for Measuring a CMP6 .........18
7.3.3.2 CR1000 Example Program for Measuring a CMP11 .......19
7.3.3.3 CR1000 Example Program for Measuring a CMP21 .......20
7.3.3.4 CR10X Example Program for Measuring a CMP6 ..........21

Table of Contents
ii
8. Maintenance .............................................................23
8.1 Cleaning Domes ................................................................................ 23
8.2 Changing the Desiccant..................................................................... 24
8.3 Check Sensor Output......................................................................... 24
8.4 Recalibration ..................................................................................... 25
9. Troubleshooting.......................................................25
Appendix A. CVF3, CVF4 Heater Ventilator.............A-1
A.1 General Information ........................................................................ A-1
A.2 Siting ............................................................................................... A-1
A.3 Installation....................................................................................... A-2
A.3.1 CVF3........................................................................................ A-3
A.3.2 CVF4 Installation ..................................................................... A-5
A.4 Wiring ............................................................................................. A-7
A.5 Maintenance .................................................................................... A-7
A.5.1 CVF3........................................................................................ A-7
A.5.2 CVF4........................................................................................ A-8
Figures
Figure 4-1 Pyranometer installation................................................................ 3
Figure 4-2 Pyranometer mounted horizontally for the Northern Hemisphere
(left) and Southern Hemisphere (right) ............................................ 3
Figure 4-3 Two views of a pyranometer mounted at an angle for the Northern
Hemisphere ...................................................................................... 4
Figure 4-4 Pyranometer mounted at an anlge for the Southern Hemispher .... 4
Figure 4-5 SCWin Short Cut Program Generator ........................................... 5
Figure 6-1 Dimensions of the CMP6, CMP11, and CMP21........................... 8
Figure 6-2 Dimensions of the CVF3 ............................................................... 8
Figure 6-3 Dimensions of the CVF4 ............................................................... 9
Figure 7-1 CM245 bracket with 2.125" u-bolts positioned to mount the
pyranometer horizontally on a crossarm ........................................ 10
Figure 7-2 CM245 bracket with 1.5" u-bolts positioned to mount pyranometer
at a 40° angle on a vertical pipe ..................................................... 11
Figure 7-3 Exploded view of the pyranometer mounting ............................. 12
Figure 7-4 CMP6, CMP10, CMP11, or CMP21 thermopile detector schematic
....................................................................................................... 13
Figure 8-1 Reading is reduced if dome is not dry or clean ........................... 23
Figure 8-2 Changing the desiccant................................................................ 24

Tables
TABLE 6-1. CMP-Series Specifications ........................................................7
TABLE 7-1. CMP6, CMP10 and CMP11 Differential Connections to
Campbell Scientific Dataloggers ....................................................13
TABLE 7-2. CMP6, CMP10 and CMP11 Single-Ended Connections to
Campbell Scientific Dataloggers ....................................................14
TABLE 7-3. CMP21 Differential Connections to Campbell Scientific
Dataloggers.....................................................................................14
TABLE 7-4. CMP21 Single-Ended Connections to Campbell Scientific
Dataloggers.....................................................................................15
TABLE 7-5. Multipliers Required for Flux Density and Total Fluxes .........16
TABLE 7-6. CR1000 Wiring for CMP6 Example Program.........................18
TABLE 7-7. CR1000 Wiring for CMP11 Example Program.......................19
TABLE 7-8. CR1000 Wiring for CMP21 Example Program.......................20
TABLE 7-9. CR10X Wiring for CMP6 Example Program ..........................21
TABLE A-1. CVF3 Wiring ....................................................................... A-7
TABLE A-2. CVF4 Wiring ....................................................................... A-7

1
CMP6-L, CMP10-L, CMP11-L, and
CMP21-L Pyranometers
1. Introduction
CMP-series pyranometers are designed for continuous outdoor monitoring of
solar radiation intensity. A flat spectral sensitivity from 285 to 2800 nm
enables accurate measurements in natural sunlight, under plant canopies, and in
green houses or buildings. When inverted, these pyranometers can measure
reflected solar radiation. Uses include monitoring global horizontal irradiance
(GHI) and plane of array irradiance (POA). Diffuse sky radiation can also be
measured with the use of a shade mechanism.
CMP-series pyranometers are manufactured by Kipp & Zonen, and cabled by
Campbell Scientific.
Before using these pyranometers, please study:
xSection 2, Cautionary Statements
xSection 3, Initial Inspection
xSection 4, Quick Start
More details are available in the remaining sections.
2. Cautionary Statements
xCMP-series pyranometers are rugged, but they should be handled as
precision scientific instruments.
xCare should be taken when opening the shipping package to not damage or
cut the cable jacket. If damage to the cable is suspected, consult with a
Campbell Scientific applications engineer.
3. Initial Inspection
Check the contents of the shipment. If there is a shortage (see Section 3.1,
Ships With), contact Campbell Scientific. If any damage has occurred during
transport, immediately file a claim with the carrier and contact Campbell
Scientific to facilitate repair or replacement.
The model number and cable length are printed on a label at the connection end
of the cable. Check this information against the shipping documents to ensure
the correct product and cable length are received.

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
2
3.1 Ships With
(2) Bolts for mounting from original manufacturer
(1) Sun Shield from original manufacturer
(2) Nylon washers from original manufacturer
3.2 Calibration Certificate
Each pyranometer is shipped with an instruction manual provided by Kipp &
Zonen that contains information concerning its construction, spectral
sensitivity, cosine response, and a simple sensor check out procedure. Included
with the sensor and manual is a calibration certificate with the sensor
sensitivity value and serial number.
Cross check this serial number against the serial number on your
pyranometer to ensure that the given sensitivity value corresponds
to your sensor.
4. Quickstart
Appendix A, CVF3, CVF4 Heater/Ventilator, provides the
installation procedure for both ventilation units.
4.1 Siting
The pyranometer is usually installed horizontally for global horizontal
measurements. However, the pyranometer can be installed at any angle for
POA measurements and in the inverted position for reflected measurements. In
all cases it will measure the solar flux incident on the sensor surface.
Site the pyranometer to allow easy access for maintenance while ideally
avoiding any obstructions above the plane of the sensing element. It is
important to mount the pyranometer such that a shadow will not be cast on it at
any time.
If this is not possible, try to choose a site where any obstruction over the
azimuth range between earliest sunrise and latest sunset has an elevation not
exceeding 5q. Diffuse solar radiation is less influenced by obstructions near
the horizon. For instance, an obstruction with an elevation of 5qover the
whole azimuth range of 360qdecreases the downward diffuse solar radiation
by only 0.8%.
The sensor should be mounted with the cable pointing towards the nearest
magnetic pole (e.g., in the Northern Hemisphere point the cable toward the
North Pole); see Figures 4-1 to 4-4.
Note
Note

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
3
4.2 Mounting
See Section 7.1, Mounting to a Tripod Tower, for more information.
Figure 4-1 Pyranometer installation
Figure 4-2 Pyranometer mounted horizontally for the Northern
Hemisphere (left) and Southern Hemisphere (right)
CM245 Adjustable
Angle Mounting
Stand
CM2XX-Series
Crossarm

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
4
Figure 4-3 Two views of a pyranometer mounted at an angle for the
Northern Hemisphere
Figure 4-4 Pyranometer mounted at an anlge for the Southern
Hemisphere

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
5
4.3 Datalogger Programming/Wiring
The simplest method for programming the datalogger to measure a CMP6,
CMP10 or CMP11 is to use Campbell Scientific's SCWin Short Cut Program
Generator (see Figure 4.5). Wire the pyranometer according to the wiring
diagram generated by Short Cut.
The CMP21 is not included in Short Cut. Refer to Section 7,
Installation, for wiring and programming information if not using
Short Cut.
Figure 4-5 SCWin Short Cut Program Generator
Note

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
6
5. Overview
5.1 Models
CMP-series models differ in accuracy and performance. See Section 6,
Specifications. The CMP21 also includes an internal thermistor allowing
individually optimized compensation of the measurements. The –L portion of
the model number indicates that the pyranometer has a user-specified cable
length. The pyranometers have several cable termination options. Their cables
can terminate in:
xPigtails that connect directly to a Campbell Scientific datalogger
(cable termination option –PT).
xConnector that attaches to a prewired enclosure (cable termination
option –PW).
xConnector that attaches to a CWS900 Wireless Sensor Interface (cable
termination option –CWS). The CWS900 enables the pyranometer to
be used in a wireless sensor network. Please note that this option is
not available for the CMP21.
5.2 Construction
The pyranometers consist of a thermopile sensor, housing, two glass domes,
and cable. The thermopile is coated with a black absorbent coating. The paint
absorbs the radiation and converts it to heat. The resultant temperature
difference is converted to a voltage by the copper-constantan thermopile. The
thermopile is encapsulated in the housing in such a way that it has a field of
view of 180 degrees and the angular characteristics needed to fulfill the cosine
response requirements.

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
7
6. Specifications
6.1 Pyranometers
Table 6-1 CMP-Series Specifications
Specification
CMP6
CMP10 and CMP11
CMP21
ISO Classification
First Class
Secondary Standard
Maximum irradiance
2000 W•m–2
4000 W•m–2
Spectral range
(50% points)
285 to 2800 nm
Response time (95 %)
<18 s
<5 s
Expected daily
uncertainty
<5% <2%
Zero offset due to
thermal radiation
(200 W•m
–2
)
<15 W•m–2<7 W•m–2
Zero offset due to
temperature change
(5 K•hr
–1
)
<4 W•m–2<2 W•m–2
Non-stability
(change/year)
<1 % <0.5%
Non-linearity
(0 to 1000 W•m
–2
)
<1% <0.2%
Directional error
(up to 80° with 1000
W•m
–2
beam)
<20 W•m–2<10 W•m–2
Tilt error
(at 1000 W•m
–2
)
<1% <0.2%
Level accuracy
0.1°
Operating temperature
–40° to 80°C
Temperature dependence
of sensitivity
<4% (–10° to +
40°C)
<1% (–10° to +4
0°C)
<1% (–20° to +5
0°C)
Sensitivity
5 to 20 μV / W•m–2
7 to 14 μV / W•m–2
Typical signal output for
atmospheric applications
0 to 20 mV 0 to 15 mV
Weight
0.6 kg (1.3 lb) without cable;
0.9 kg (2 lb) with 10 m (33 ft) cable
Impedance*
20 to 200 Ω
10 to 100 Ω
* Impedance is defined as the total electrical impedance at the radiometer output connector fitted to the housing.
It arises from the electrical resistance in the thermal junctions, wires, and passive electronics within the
radiometer.

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
8
Figure 6-1 Dimensions of the CMP6, CMP11, and CMP21
6.2 CVF3 Ventilation Unit
Compatible Pyanometers: CMP6, CMP10, CMP11, CMP21
Power supply: 12 Vdc, 1.3 A (with 10 W Heater)
Operating temperature range: –40° to 70°C
Ventilation power: 5 W continuously
Heating power: 5 W and 10 W
Heater induced offset: <1 W•m–2(with CMP11 Pyranometer)
Weight without cable: 1.6 kg (3.5 lb)
Figure 6-2 Dimensions of the CVF3
6.3 CVF4 Ventilation Unit
Compatible Pyanometers: CMP6, CMP10, CMP11, CMP21
Power supply: 12 Vdc, 0.9 A (with Heater)

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
9
Operating temperature range: –40° to 70°C
Ventilation power: 5 W continuously
Heating power: 5.5 W
Heater induced offset: <1 W•m–2(with CMP10, CMP11
Pyranometer)
Weight without cable: 1.6 kg (3.5 lb)
Figure 6-3 Dimensions of the CVF4
7. Installation
7.1 Mounting to a Tripod or Tower
Tools required for installation on a tripod or tower:
Small and medium Phillips screwdrivers
5/16”, 1/2” open end wrenches
5/32” Allen wrench
Tape measure
UV-resistant wire ties
Side-cut pliers
Compass
Step ladder
The pyranometers include a bubble level and two leveling screws, which allow
them to be leveled horizontally without using a leveling base. They mount to a
mast, crossarm, or pole (1.0 in. to 2.1 in. outer diameter) via the CM245
Mounting Stand.

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
10
If using a CFV3 or CVF4 Ventilation Unit, a different mounting
stand, the 27084 is required. Refer to Appendix A, CVF3 and
CVF4 Heater/Ventilator, for more information.
The CM245 includes slots that allow it to be adjusted to any angle from
horizontal to vertical. If mounting the pyranometer at an angle, ensure that the
crossarm is leveled horizontally before placing the bracket at its proper angle.
Angle positions are included on the bracket label (see Figures 7-1 and 7-2).
Figure 7-1 CM245 bracket with 2.125" u-bolts positioned to mount the
pyranometer horizontally on a crossarm
Note
First
2.125”
u-bolt
Second
2.125”
u-bolt
Second
2.125”
u-bolt
First
2.125”
u-bolt
90
Pyranometer
mounts here

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
11
Figure 7-2 CM245 bracket with 1.5" u-bolts positioned to mount
pyranometer at a 40° angle on a vertical pipe
Do the following to level the pyranometer horizontally (see Error! Reference
ource not found.):
1. Attach the mounting stand to the crossarm.
2. Loosely mount the pyranometer on the mounting stand. Do not fully
tighten the two mounting screws.
3. Turn the leveling screws as required to bring the bubble of the level within
the ring.
4. Tighten the mounting screws to secure the assembly in its final position.
Check that the pyranometer is still correctly leveled and adjust as necessary.
5. Attach the white plastic sun screen to the pyranometer.
First
1.5”
u-bolt
Second
1.5”
u-bolt
40

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
12
6.
Figure 7-3 Exploded view of the pyranometer mounting
7.2 Wiring
Short Cut users should wire the sensor according to the wiring
diagram generated by Short Cut.
The cable of the CMP6, CMP10 and CMP11 has two conductors and a shield.
The cable of the CMP21 has five conductors and a shield. The additional
conductors on the CMP21’s cable are for connecting its internal thermistor. A
schematic for the CMP6, CMP10, CMP11, and the thermopile of the CMP21 is
provided in Section 7.2.1 CMP6, CMP11, and CMP21 Thermopile Schematic.
Wiring for the CMP6, CMP10, and CMP11 is described in Section 7.2.2,
CMP6 and CMP11 Wiring, wiring for the CMP21 is described in Section 7.2.3,
CMP21 Wiring.
Note
Mounting screws
Levelling screw
CM245
mounting stand
Pyranometer
Crossarm
Bubble level
Nylon washers
Sun shield

CMP6-L, CMP10-L, CMP11-L, and CMP21-L Pyranometers
13
7.2.1 CMP6, CMP10, CMP11, and CMP21 Thermopile Schematic
A schematic diagram of a CMP6, CMP10, CMP11, or CMP21 thermopile is
shown in Figure 7-4.
Red
Blue
Black
Figure 7-4 CMP6, CMP10, CMP11, or CMP21 thermopile detector
schematic
7.2.2 CMP6 and CMP11 Wiring
CMP6, CMP10, or CMP11 purchased from Campbell Scientific
has different wiring than a pyranometer purchased directly from
Kipp & Zonen.
The pyranometer is measured using either differential analog channels or
single-ended analog channels.
A differential voltage measurement is recommended because it has better noise
rejection than a single-ended measurement.
Connections to Campbell Scientific dataloggers for a differential measurement
are given in TABLE 7-1. A user-supplied jumper wire should be connected
between the low side of the differential input and ground (AG or
) to keep
the signal in common mode range.
Connections to Campbell Scientific dataloggers for a single-ended
measurement are given in TABLE 7-2able 7-2.
TABLE 7-1. CMP6, CMP10 and CMP11 Differential Connections to Campbell Scientific Dataloggers
Color
Description
CR9000(X), CR5000,
CR3000, CR1000,
CR800
CR510, CR500,
CR10(X)
21X, CR7, CR23X
White
Signal (+)
DIFF Analog High
DIFF Analog High
DIFF Analog
High
Black
Signal (
–)
*DIFF Analog Low
*DIFF Analog Low
*DIFF Analog Low
Shield
Shield
G
* Jumper to AG or
with user supplied 26 AWG or larger wire.
Note
White (+)
Black (-)
Shield