Summary of Contents for Hukseflux VU01
- Page 1 USER MANUAL VU01 Ventilation unit for SR20 and SR22 pyranometers and IR20 pyrgeometers Copyright by Hukseflux | manual v1620 | www.huksefluxusa.com | info@huksefluxusa.com...
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Page 2: Warning Statements
Warning statements Always power off the ventilation unit when conducting maintenance or installing VU01. VU01 may be used with SR20, SR20-D2, SR22, SR25, SR25-D1, IR20 & IR20WS sensors. VU01 is not meant to be used with other pyranometers and pyrgeometers. -
Page 3: Table Of Contents
Maintenance and trouble shooting Recommended maintenance Life expectancy Trouble shooting Appendices Appendix on dust filter replacement Appendix on tools for VU01 Appendix on spare parts for VU01 Appendix on cable extension / replacement EC declaration of conformity VU01 manual v1614 3/25... -
Page 4: List Of Symbols
Voltage drop over cable drop Fan voltage supply Cable resistance cable Wire resistance per meter /m wire Cable length cable Fan current draw Fan status signal high S,high Fan status signal low S,low Rotation rate treshold 1/min VU01 manual v1614 4/25... -
Page 5: Introduction
VU01 provides an airflow over the instrument body and dome and has two heaters on board to heat the air. The use of heating (5W or 10W) is optional. The VU01 ventilation unit runs on 12 VDC voltage. VU01 may be used in combination with Hukseflux’ SR20, SR20-D2, SR22, SR25 and SR25-D1 secondary standard pyranometers and IR20 and IR20WS research grade pyrgeometers. - Page 6 VU01 is designed, using high-quality materials, in agreement with the recommendations of ISO/TR 9901 and BSRN. The footprint of VU01 is small, which prevents accumulation of snow. The ventilator power is relatively high in order to increase the airflow. The heaters should be activated using external relays.
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Page 7: Ordering And Checking At Delivery
The standard configuration of VU01 is with 5 metres cable. Options are: longer cable (in multiples of 5 m and a pack of 5 dust filters. Consult Hukseflux for cable options. One dust filter and one spare dust filter are included with VU01. -
Page 8: Instrument Principle And Theory
VU01 cover VU01 fixation of cover VU01 levelling feet VU01 filter retainer VU01 ventilator, heaters and filter replacement system (below cover) VU01 connector (10) VU01 cable and cable connector Ventilation promotes thermal equilibrium between all components of radiometers, and thereby reduces zero offsets. Dew and frost formation is prevented. Additional heating will promote evaporation of water droplets and sublimation of snow. -
Page 9: Specifications Of Vu01
Specifications of VU01 3.1 Specifications of VU01 VU01 is a high-quality ventilation unit that may be used with pyranometer models SR20, SR20-D2, SR22, SR25 and SR25-D1, and pyrgeometer models IR20 and IR20WS. Its purpose is to improve the dependability of the measurement. Measurement accuracy improves because offsets are reduced. -
Page 10: Dimensions Of Vu01
(330 x 250 x 220) mm VERSIONS / OPTIONS / ACCESSORIES Longer cable, in multiples of 5 metres option code = total cable length; consult Hukseflux see chapter 5.5 on installation design considerations Pack of 5 dust filters order code = VU01F 3.2 Dimensions of VU01... -
Page 11: Standards And Recommended Practices For Use
Methods of Observation, practice for use Pyrheliometers and UV chapter 7, measurement of Radiometers radiation, 7.3 measurement of global and diffuse solar radiation, 7.4 measurement of total and long-wave radiation BSRN Operations Manual, Version 2.1, April 2005 VU01 manual v1614 11/25... -
Page 12: Installation Of Vu01
Once the VU01 cover is removed, the ventilation unit can be mounted to a flat mounting surface using the supplied VU01 mounting hardware. Optionally a large hole can be made by the user in the mounting surface under VU01 if obstruction of the airflow from the sides is expected, for example by snow buildup. -
Page 13: Installation Of The Vu01 Cover
Lift the cover, tilting around positioning pin (5) Figure 5.3.1 Installation and removal of ventilator cover: (1) VU01 thumbscrew, (2) VU01 cover, (3) sensor connector, (4) VU01 connector, (5) VU01 positioning pin. Figure 5.3.2 Cutaway of VU01 showing internal components and SR20 pyranometer. -
Page 14: Electrical Connection Of Vu01
SR20 / SR22 / SR25 / IR20 cable and do not connect the SR20 / SR22 / SR25 / IR20 connector to the VU01 cable; both VU01 and the sensor will not function. Cables generally act as a source of distortion, by picking up capacitive noise. We recommend keeping the distance between VU01 and a power supply as short as possible. -
Page 15: Power Supply And Cable Length
5.5 Power supply and cable length Standard VU01 is delivered with a cable length of 5 m. Longer cable lengths, in multiples of 5 metres, are offered by Hukseflux. Please consult Hukseflux. In case of cable replacement or extension beyond 5 m, please note that the voltage drop across the regular VU01 cable becomes significant and that a cable with a lower electrical resistance must be used. - Page 16 Examples: For a cable length of 50 metres, the resistance of AWG16 is low enough to deliver 11.1 V to VU01 when using a 12 VDC power supply. For a cable length of 15 metres, AWG 26 and AWG 24 cabling should not be used because the voltage drop prohibits VU01 from receiving a sufficient amount of power.
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Page 17: Using The Status Signal For Monitoring
5.6 Using the status signal for monitoring VU01 provides users with a fan status signal which may be used to monitor rotation of the fan. Using the fan status signal is optional. The fan status signal is either high (OK) or low (not OK). - Page 18 VU01 includes an internal load resistor, allowing direct use of the fan status signal. To use the optional status signal, the user has to measure the signal between the blue (fan status signal [+]) and yellow (fan status signal [-]) wire, as shown in Figure 5.6.2.
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Page 19: Maintenance And Trouble Shooting
For maintenance and trouble shooting of pyranometers or pyrgeometers consult the SR20, SR20-D2, SR22, SR25, SR25-D1 or IR20 manual. When conducting maintenance on VU01, always power off the ventilation unit. Powering off VU01 may be done by disconnecting the VU01 connector. - Page 20 VU01 manual v1614 20/25...
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Page 21: Appendices
Dust filters have to be replaced manually. Filters may be re-used several times after cleaning with water and soap. Hukseflux offers a pack of 5 replacement dust filters as an option. The replacement interval depends on local conditions, and may vary from 1 week to 6 months. -
Page 22: Appendix On Cable Extension / Replacement
In case of cables longer than 5 metres, consult Hukseflux. See the specific paragraph in this manual about power supply and cable length. The cable of VU01 is equipped with a M16 straight connector. In case of cable replacement, it is recommended to purchase a new cable with cable connector at Hukseflux. -
Page 23: Ec Declaration Of Conformity
7.5 EC declaration of conformity Hukseflux Thermal Sensors B.V. Delftechpark 31 2628 XJ Delft The Netherlands in accordance with the requirements of the following directive: 2004/108/EC The Electromagnetic Compatibility Directive hereby declare under our sole responsibility that: Product model: VU01... - Page 25 © 2016, Hukseflux Thermal Sensors B.V. www.hukseflux.com Hukseflux Thermal Sensors B.V. reserves the right to change specifications without notice.
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