AT BF5 Manuel utilisateur
User Manual for the
Sunshine Sensor
type BF5
Delta-T Devices Ltd
BF5-UM-2.3
Notices
Copyright
All rights reserved. Under the copyright laws, this manual may not be
copied, in whole or in part, without the written consent of Delta-T Devices
Ltd. Under the law, copying includes translation into another language.
Copyright © 2022 Delta-T Devices Limited
BF5 Sunshine Sensor optics design and theory are Copyright © 1996
John Wood, Peak Design & Development, Winster, Derbyshire, U.K. and
protected by Patent Nos. EP1012633 & US6417500.
Trademarks
Windows is a registered trademark of Microsoft Corporation.
All other trademarks are acknowledged. Some names referred to are
registered trademarks.
CE Conformity
The BF5 Sunshine Sensor conforms to EU regulations regarding
electromagnetic emissions and susceptibility and is CE marked by
Delta-T Devices Ltd.
For certificates look on our website at www.delta-t.co.uk ,
or the Delta-T Software and Manual DVD.
Warnings
To maintain conformance to CE standards, the equipment must be used
as described in this manual. Modifications to the equipment may invalidate
CE certifications.
Delta-T Devices Ltd reserves the right to change the designs and
specifications of its products at any time without prior notice.
Authors
John Wood, Edmund Potter, Stephen Nobbs, Nick Webb.
User Manual Version: 2.3 Jul 2022
Delta-T Devices Ltd Tel: +44 (0)1638 742922
130 Low Road, Burwell Fax: +44 (0)1638 743155
CAMBRIDGE CB25 0EJ e-mail: sales@delta-t.co.uk
U.K. www: http://www.delta-t.co.uk
BF5 User Manual v 2.3 Contents 3
Contents
1
Notices 2
Introduction 6
About this Manual 6
Description and Functions 6
What it measures 6
What it is used for 7
Advantages of BF5 7
SunRead software 7
Use with a data logger 7
Use with SunScan 8
Differences from BF1, BF2 and BF3 8
Construction 9
Heater 9
Accessories 11
Mounting 11
Cables 11
Power Considerations 12
Heater 13
Getting Started 15
PC software 15
SunRead Installation 15
Connect your BF5 16
Preliminary Checks 17
Battery and Desiccant 17
Check the Dome 17
Use with SunScan 18
Setting up the BF5 18
Connecting to SunScan 18
Environment and Moisture protection 19
Use with a data logger 20
Effect of engineering units on sensitivity and resolution 20
Sunshine Status Output 20
Analogue outputs 21
Simplified output schematic 22
Suggested power supply connections 23
4 Contents BF5 User Manual v 2.3
Suggested Sun output connections 25
Ground and screen connections 27
Delta-T data logger connections 28
GP1 logger 28
GP2 Logger 28
DL2e logger 28
DL6 logger 28
Technical reference 29
Specifications 29
BF5 Accuracy and Resolution 29
Other specifications 30
BF5 Components Specifications 31
BF5 - SunScan Cable 31
BF5 Logger Cable 31
BF5 Analogue Extension Cables Can be used to extend both
BF5-Sunscan cable and BF5-Logger Cables 31
RS232 Serial Cable 31
Serial Extension Cable 32
Telescopic Tripod 32
Cross Arm for Mast Mount 32
Cosine response 33
Spectral response 34
Routine Maintenance 35
Batteries 35
Desiccant 35
Maintaining the dome 35
Recalibration of BF5 35
Warranty and Service 38
Terms and Conditions of Sale 38
Service and Spares 39
Technical Support 39
Contact details: 39
Problems 40
Problem Reports 40
Troubleshooting 40
BF5 Not Responding 40
Appendix A: Design and Test Summary 41
Introduction 41
Design objectives 41
How the design evolved 41
Calculation of Outputs 42
Conversion to appropriate units 42
BF5 User Manual v 2.3 Contents 5
Molar units (mol.m-2.s-1) 42
Energy units (W.m-2) 42
Illuminance units (lux) 43
Sunshine state 43
Glossary 48
Index 49
6 Introduction BF5 User Manual v 2.3
Introduction
About this Manual
This manual describes the BF5 Sunshine Sensor, and how to use it.
SunScan Users: If using the BF5 with the SunScan Canopy Analysis
system refer to the Preliminary Checks on page 17 and Use with
SunScan on page 18.
See also the SunScan documents on the Software and Manuals DVD.
Appendix 1 describes the BF5 design and includes a summary of the test
results of several experimental trials of its predecessors, the BF3 & BF2.
See also:
BF5 Quick Start Guide
BF3 Optical Design v2
BF3 Evaluation
These are also on the Software and Manuals DVD.
Description and Functions
What it measures
The BF5 Sunshine Sensor is one sensor with three output channels:-
1. Total (global) solar radiation
2. Diffuse radiation
3. Sunshine status.
The Direct beam component of solar radiation can be calculated from
the Total minus the Diffuse component.
You can set up the two radiation outputs to give millivolt signals
scaled to the radiation units of your choice:
For PAR, in mol.m-2.s-1
For Energy, in W.m-2 ,or
For Illuminance, in klux .
The Sunshine status output is a logic level that corresponds to
sun, or no sun. This can be processed to give sunshine hours
duration.
The Sunshine status threshold corresponds to the World Meteorology
Office (WMO) value of 120 W.m-2 in the direct beam, using an
BF5 User Manual v 2.3 Introduction 7
algorithm based on the Total radiation, and the ratio of Total to
Diffuse radiation.
The radiation outputs have a cosine-corrected response.
What it is used for
SunScan Canopy Analysis System reference
Canopy analysis studies, and HemiView reference information
Meteorological Global Direct and Diffuse solar radiation and Sunshine
duration measurements
Solar energy monitoring, and solar collector studies
Architecture and building design, illumination and heat balance
studies of buildings
Advantages of BF5
It requires no shadow band.
There are no moving parts.
It does not need to be adjusted or repositioned to track the sun – a
distinct advantage over devices with shadow rings.
It does not need to be oriented towards North. It will work accurately
in any orientation as long as it is mounted horizontally.
It does not require knowledge of the Latitude or Longitude, and can
be used at any Latitude or Longitude.
It measures sunshine hours as well as Total and Diffuse radiation
A heater allows use in condensing and frosty situations.
SunRead software
SunRead runs on a PC running Windows 10, 8, 7, Vista XP.
About SunRead
Reads the BF5 output values and status information via the PC
RS232 serial port.
Sets the BF5 output units, to mol.m-2.s-1 (PAR), or W.m-2 (Energy), or
klux (Illuminance) as required.
Logs data directly to PC.
Use with a data logger
The three outputs of the BF5 can be logged with a suitable data
logger. The Total and Diffuse radiation millivolt outputs require two
analogue channels. The use of a data logger with differential sensor
inputs (rather than single-ended) is recommended.
8 Introduction BF5 User Manual v 2.3
The sunshine state logic output can be taken to a digital channel, or
for some purposes can be connected to an analogue channel in order
to give readings of sunshine duration.
The BF5 is a powered sensor. For power economy, the BF5 can be
woken up via a warm-up signal from the data logger.
The internal heater requires a separate power supply. This should be
completely isolated from all other BF5 ground connections.
Use with SunScan
The SunScan system is used for measuring PAR (Photosynthetically
Active Radiation) interception by plant canopies, and hence
estimating Leaf Area Index (LAI).
The BF5 can be connected to SunScan probe to provide an
instantaneous reference of solar radiation incident on the canopy.
The measurements give the incident Diffuse and Total PAR above
the canopy. This also improves the accuracy of estimating canopy
LAI.
Differences from BF1, BF2 and BF3
The BF1 was a very simple sensor consisting of two PAR
photodiodes and an adjustable shadow band. It measured Total and
Diffuse PAR. It required alignment to true North, and the shadow
band required frequent adjustment.
The BF2 design measured Total and Diffuse PAR without needing
any adjustment or North alignment, only horizontal levelling. The BF2
also measured Sunshine state.
The BF3 used the same optical design as the BF2, but gave the user
a choice of output units for Total and Diffuse radiation, in mol m-2 s-1
(PAR) , Wm-2 (Energy) , or klux (Illuminance) , as well as Sunshine
state.
The BF5 has the same performance and specifications as the BF3, but
with an improved electronic and mechanical design.
The power consumption is improved:- the external power requirement
reduced from 6.5 to 2 mA, the number of internal AA batteries
reduced from four to two, and their typical lifetime increased from 6 to
12 months.
The accuracy of the analogue outputs has been improved, with the
output offset reduced to 3mV.
There are now no internal jumpers or fuses.
The design also includes a heater and more rugged and weather-
proof cabling connectors and extension cables which are now
interchangeable with the SPN1 Sunshine Pyranometer.
BF5 User Manual v 2.3 Introduction 9
Construction
Seven cosine-corrected photodiodes are arranged under a patterned,
hemispherical dome, along with a levelling bubble, a desiccant-status
indicator, and a red light emitting diode (LED). The LED flashes when the
photodiodes are powered up for a reading.
There are two panel mounted sockets for communications:
An 8 pin, M12 male analogue socket for connection to SunScan or to
a data logger.
This can also connect to a logger warm-up power supply for the BF5
sensor and to a separate power supply for the heater.
A 5-pin M12 male connector serial port for connection to a PC or to
the SunScan radio link option.
The serial port is provided for checking real time readings, for changing
the output units, and for logging data directly to the PC.
A camera tripod type connector (1/4” BSW thread) is fitted to the base.
Heater
The BF5 is fitted with a thermostatically controlled heater for protection
against frost and condensation. Its use is recommended for logging
applications. It requires a separate external 12V DC power supply.
Use of the heater stabilises the internal temperature of the BF5 in cold
conditions, keeping the dome free of frost and resulting in greater
measurement accuracy.
The heater consists of two 15W resistors fixed to the shadow-mask.
When power is applied to the heater it works as follows:-
If the external temperature is above 5C, the heater provides 2W,
reducing to zero above 35C.
This is sufficient to remove condensation and dew.
Whenever the temperature drops below 5C the heater is increased,
to full power below 0C - to remove snow or ice.
At zero wind speed a BF5 at minus 20C will become snow and ice free in
30 minutes once power is applied to the heater.
At 2m.s-1 wind speed the dome will remain snow and ice free down to
minus 10C.
Warning:The bare heaters can get hot enough to burn your skin when on.
Do not operate the heaters with the dome removed.
Warning: Ensure the heater ground is isolated from all other BF5 ground
connections. If possible use a data logger with differential sensor inputs.
See also page 21
10 Introduction BF5 User Manual v 2.3
Cable connectors and components inside the dome
Section through BF5, showing internal PCBs and battery pack
Table des matières
