Kipp & Zonen CSD1 User manual

INSTRUCTION MANUAL
Kipp
Zonen
&
0342 300
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SUNSHINE DURATION METER

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IMPORTANT USER INFORMATION
Reading this entire manual is recommended for full
understanding of the use of this product.
The exclamation mark within an equilateral triangle is intended to alert the
user to the presence of important operating and maintenance instructions in
the literature accompanying the instrument.
Should you have any comments on this manual we will be pleased to
receive them at:
Kipp & Zonen B.V.
Röntgenweg 1 2624 BD Delft Holland
P.O. Box 507 2600 AM Delft Holland
Phone [phone]
Fax [phone]
E-mail [e-mail]
Kipp & Zonen reserve the right to make changes to the specifications without
prior notice.
WARRANTY AND LIABILITY
Kipp & Zonen guarantees that the product delivered has been thoroughly
tested to ensure that it meets its published specifications. The warranty
included in the conditions of delivery is valid only if the product has been
installed and used according to the instructions supplied by Kipp & Zonen.
Kipp & Zonen shall in no event be liable for incidental or consequential
damages, including without limitation, lost profits, loss of income, loss of
business opportunities, loss of use and other related exposures, however
caused, arising from the faulty and incorrect use of the product.
User-made modifications can affect the validity of the CE declaration.
COPYRIGHT©2003 KIPP & ZONEN
All rights reserved. No part of this publication may be reproduced, stored in a
retrieval system or transmitted in any form or by any means, without
permission in written form from the company.
Manual version 0104

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DECLARATION OF CONFORMITY
According to EC guideline 89/336/EEC
We Kipp & Zonen B.V.
Röntgenweg 1
2624 BD Delft
declare under our sole responsibility that the product
Type: CSD 1
Name: SUNSHINE DURATION SENSOR
to which this declaration relates is in conformity with the following standards
Imissions EN 50082-1 Group standard
IEC 100-4-2 IEC 801-2 8 kV
IEC 100-4-3 IEC 801-3 3 V/m
IEC 100-4-4 IEC 801-4 1 kV
Emissions EN 50081-1 Group standard
EN 55022
following the provisions of the directive
R.E. Ringoir
Product management
KIPP & ZONEN B.V.

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TABLE OF CONTENTS
IMPORTANT USER INFORMATION............................................................3
DECLARATION OF CONFORMITY .............................................................5
TABLE OF CONTENTS................................................................................ 7
1. GENERAL INFORMATION.....................................................................9
1.1 USING THE CSD 1 ..........................................................................................9
1.2 THE MINIMUM NECESSARY REQUIREMENTS.......................................... 11
1.3 INSTALLATION .............................................................................................. 11
1.4 MEASUREMENT OF SUNSHINE DURATION .............................................. 14
1.5 MEASUREMENT OF DIRECT RADIATION ..................................................15
1.6 USING THE HEATER .................................................................................... 15
1.7 CALIBRATION & QUALITY CONTROL ......................................................... 15
1.8 MAINTENANCE ............................................................................................. 16
1.9 OPTICAL THEORY ........................................................................................ 16
2. PROPERTIES OF CSD 1 ...................................................................... 19
2.1 SPECIFICATIONS OF THE SUNSHINE DURATION MEASUREMENT....... 19
2.2 SPECIFICATIONS OF THE DIRECT RADIATION MEASUREMENT ........... 19
2.3 SPECIFICATIONS OF THE HEATER............................................................ 20
3. TROUBLE SHOOTING .........................................................................21
4. ADJUSTMENT OF THE CALIBRATION FACTOR...............................23
5. DELIVERY.............................................................................................27
6. SPARE PARTS .....................................................................................29
7. ELECTRICAL DIAGRAMS ...................................................................31
8. RECALIBRATION SERVICE ................................................................ 33

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1. GENERAL INFORMATION
CSD 1 is a sensor for measurement of sunshine duration. The sunshine
duration is defined as the time during which the direct solar radiation
exceeds the level of 120 W/m².
CSD 1 can also supply a derived value of the level of direct radiation.
CSD 1 was designed for use in agricultural meteorology (evaporation), for
tourist information (number of sunshine hours), for building automation
(automatic control of sunscreens), and for health resorts (climatology for
treatment and recovery).
One of the main features of CSD 1 is the built-in two-level heating, which
can remove dew, frost and even ice. In many applications this provides a
significant improvement in the reliability of the measurement.
CSD 1 employs 3 detectors, each covering part of the sky. The direct
radiation is calculated from the differences in signal levels.
Great care has been taken to design the angular characteristics of the
detector, resulting in a measurement that can be used anywhere on Earth in
a fixed position, and that minimises seasonal effects.
The three detectors have exactly the same spectral and angular
characteristics. This makes the process of recalibration very easy.
CSD 1 has no moving parts and low power consumption.
The following chapters will explain the various aspects of using CSD 1.
1.1 USING THE CSD 1
Using CSD 1 is easy. Figure 1.1 shows the dimensions. The unit must be
installed, using the mounting hole in the instrument arm. The sunny/not
sunny switched output for sunshine duration must be connected to a
recorder with a voltage input. If desired the continuous output of the
estimated direct radiation can be connected to another voltage recorder.
If the instrument is covered by dew, frost or snow, the measurement can be
improved by switching on the built-in heater.

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Typically the unit will run without attendance. Paragraphs 1.2 to 1.6 expand
upon the above.
CSD 1 should be regularly maintained and if possible be re-calibrated once
every year in order to check the instrument stability. These items are
addressed in 1.7 and 1.8.
More about the optical theory can be found in 1.9.
Figure 1.1 Dimensions of CSD 1

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1.2 THE MINIMUM NECESSARY REQUIREMENTS
For working with CSD 1 at least 1 channel of data acquisition is needed.
Usually the measurement values are stored and integrated during each day.
After a day of measurement, the daily total is usually stored and reset to 0.
The output of the sunshine duration signal is 0 Volt when it is not sunny, or 1
Volt if the direct solar radiation exceeds the level of 120 W/m².
Secondly one needs a suitable place for installation. The most suitable
location is a where the sun is visible during the full day. An open horizon is
best. In any case, during the day there should always be exposure to the
direct radiation.
The sensor needs power from a source that can provide 9-15 VDC at a
power of 10 mW (without heating on). This can easily be supplied by a small
solar panel or a battery.
When using the measurement of the direct radiation, an additional voltage
channel of data acquisition is required.
The expected output range is 0-1000 mV.
When using the heaters, additional power must be supplied. There are two
power levels available at 12 VDC, 1 Watt and 10 Watts.
1.3 INSTALLATION
For proper installation one must know the latitude of the location and have a
map or compass available to determine the North-South axis.
When using a mast, the CSD 1 must be mounted south of the mast in the
northern hemisphere, north of the mast in the southern hemisphere, to avoid
the shadow of the mast falling on the instrument.
As seen from above, the instrument “axis" must be North-South.

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As seen from figure 1.3.1, the angle between the instrument axis and a
horizontal plane should be equal to the latitude of the installation location.
Installing like this the measurement is optimised.
When connecting the wiring, make sure to shield the power and signal
cables as much as possible.
Figure 1.3.1 installation of the CSD 1. The unit has to be installed at an
angle that depends on the latitude of the location, and be
positioned parallel to the North-South axis.

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Figure 1.3.2 a global view of the installation of the CSD 1

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colour signal outputs
red
blue
grey
not sunny/sunny 0 V/1 V
both signals ground
direct radiation, 1 W/m21 mV
colour power input
brown
yellow
power supply + 12 VDC
power supply ground
colour heater inputs
white
black
green
heater supply 10 W +12 VDC
both heaters common 0 V
heater supply 1 W +12 VDC
Figure 1.3.3 wiring schedule of CSD 1. Outputs: sunshine duration, direct
radiation, Inputs: heater low, heater high, power supply.
1.4 MEASUREMENT OF SUNSHINE DURATION
For measurement of sunshine duration, connect the power supply input and
the sunshine duration output. If the direct radiation level is higher than 120
W/m² by definition the time should be added to the sunshine duration. The
output voltage is 1 V. When the sun is not shining the output is 0V.
The usual procedure is to integrate the period with high output, and to store
either the 1 minute values or the totals for each day.

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1.5 MEASUREMENT OF DIRECT RADIATION
An output representing the direct radiation is available. This signal is 0 V
when no direct radiation is present, and varies linearly with the irradiance.
The calibration is factory set at a level of 1 mV equivalent to 1W/m2.
Measuring this parameter can be useful because the information in the
sunshine duration signal is limited, only showing if this signal is above or
below a certain level.
Note: This signal is not a substitute for Pyranometer/Pyrheliometer
measurements and does not have the same level of accuracy.
1.6 USING THE HEATER
One of the major error sources in the sunshine duration measurement is the
obstruction of the light by water that is deposited on the instrument. This can
be caused by rain, dew, frost or snow, and can be greatly reduced by
heating the instrument.
CSD 1 has on-board heaters that can be used at two levels. The heaters are
simple high power resistors that deliver 1 or 10 Watts at the recommended
supply voltage of 12 VDC. Switching of the heating levels can be done
externally with a switch or by a thermostat system (not included).
The low level heating will keep dew away and heating at the high level will
melt snow and ice at an ambient temperature not lower than -15 °C
It is recommended to use the heater only when this is strictly necessary. At
ambient temperatures of more than +10 °C the heater could be conditionally
switched off. Also in order to save power, during the night it is suggested not
to use the heater.
1.7 CALIBRATION & QUALITY CONTROL
CSD 1 has 3 detectors that have exactly the same spectral and angular
characteristics. This will benefit the process of re calibration. At Kipp &
Zonen, the calibration is done against a reference that is traceable to a
broadband solar radiation measurement under clear sky conditions.

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Re-calibration should preferably be carried out by Kipp & Zonen.
If done locally, the resistors for adjusting the sensitivity are accessible. A
special chapter has been dedicated to the procedure for adjustment of the
sensitivity.
1.8 MAINTENANCE
CSD 1 needs limited maintenance only. Regular cleaning of the transparent
window is recommended. If the desiccant in the plastic cartridge on top of
the instrument has turned pink (normally it is blue), this indicates saturation
with water. The tube can be opened and refilled. It is possible to recondition
the desiccant by heating it in an oven at 300°C for 15 minutes.
1.9 OPTICAL THEORY
The sunshine duration is defined as the time during which the direct solar
radiation exceeds the level of 120 W/m2. The reference measurement of
direct radiation can be done using a radiation sensor with a limited field of
view (a Pyrheliometer) and pointing this towards the sun (typically done
using a solar tracker).
CSD 1 is an instrument that is primarily designed to offer a relatively simple
way of measuring the sunshine duration. Relative to the standard method,
several compromises had to be made. The direct radiation level is not
determined directly, but derived from a differential measurement between
the signal levels of several detectors. Also the full solar spectrum is not
measured due to the response characteristics of the detectors.
This philosophy has made it possible to make a sensor that does not require
moving parts, and has a relatively low cost.
Further features of the CSD 1 design are:
Low power consumption;
Easy to recalibrate;
Minimal seasonal effects;
Installation at any latitude and longitude.

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Figure 1.9.1 CSD 1 with its three detectors, D1, D2 and D3.
The way that CSD 1 works is as follows:
CSD 1 has three detectors, D1, D2 and D3. D1 detects all the solar
radiation, direct and diffuse. D2 and D3 only cover part of the sky; the part
that is covered by D2 is not seen by D3.

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The electronics of CSD 1 first determines whether D2 or D3 is receiving
direct radiation (maximum signal). It chooses the detector with the smallest
signal, and assumes that this output represents approximately
1
/
3
of the
diffuse radiation. Some corrections, C, for geometry are made, (see the
formula below).
The value of D1 is reduced by the estimated value of the diffuse radiation to
result in the direct radiation.
Direct radiation = D1 - C * (smallest of D2 and D3)
Where D1, D2, D3 are the signals of detectors D1, D2, D3. C is a geometry correction.
This direct radiation signal can be monitored at one of the instrument outputs
and is compared internally with a voltage reference equivalent to the 120
W/m² level recommended by WMO, in order to switch the sunny/not sunny
output signal for sunshine duration.
Sunshine Duration output high (sunny) if direct radiation > 120 W/m².

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2. PROPERTIES OF CSD 1
Measurement accuracy was determined by experimental comparison with
reference instruments that are traceable to WRR (Word Radiometer
Reference) standards.
Operating temperature of CSD1 -30 °C (10 W heating on)
to +70 °C (no heating)
Location any longitude and latitude
Required power supply
without heating < 0.1 W at 12 VDC
heating low level 1 W ± 0.1 W at 12 VDC
heating high level 10 W ± 1 W at 12 VDC
2.1 SPECIFICATIONS OF THE SUNSHINE DURATION
MEASUREMENT
Estimated accuracy of the sunshine duration measurement
sunny > 120 ± 40 W/m² 1 ± 0.1 V
not sunny < 120 ± 40 W/m² 0 ± 0.1 V
2.2 SPECIFICATIONS OF THE DIRECT RADIATION
MEASUREMENT
Estimated accuracy of the direct radiation measurement
output level 1 mV/W/m² ± 33% at 120 W/m²
expected output range 0-1000 mV

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2.3 SPECIFICATIONS OF THE HEATER
Power supply heating low level 1 W ± 0,1 W at 12VDC
Power supply heating high level 10 W ± 1 W at 12VDC
Expected temperature range for melting ice
heating low level only dew removal
heating high level 0 °C to -15 °C (wind <1 m/s)