Hukseflux VU01, Руководство пользователя

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VU01 manual v1614 5/25
Introduction
VU01 is a high-quality ventilation unit for use with SR20 and SR22 pyranometers and
IR20 pyrgeometers. Its purpose is to improve the dependability of the measurement.
Measurement accuracy improves because offsets are reduced. Reliability benefits from
prevention of dew and frost formation and quick evaporation and sublimation of water
and snow. ISO/TR 9901
“Solar Energy - Field Pyranometers - Recommended practice for
use” recommends use of ventilators wher e high accuracy and reliability are required.
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.
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. It should be noted
that heating in combination with pyranometers will lead to increased thermal offsets, so
heating is only recommended if necessary.
Using VU01 is easy. The ventilator is generally used continuously; the heater is typically
controlled by the datalogger. ISO/TR 9901 “Solar Energy - Field Pyranometers -
Recommended practice for use” recommends use of ventilators where high accuracy and
reliability are required. More details can be found in paragraph 5.2.2 and annex A. The
Baseline Surface Radiation Network, BSRN, recommends ventilation for radiometers in its
BSRN operations manual v2.1.
Figure 0.1
VU01 ventilation unit with SR20 secondary standard pyranometer