Renseignements généraux

Nº de série

40380

Nº de partie

1

Nombre total de parties

1

Ou

Wind monitor

Brevets

S/O

Description générale

synthetic body, shaft, propeller and parts/ metal clamp and parts

Dimensions

Remarque : Cette information reflète la taille générale pour l’entreposage et ne représente pas nécessairement les véritables dimensions de l’objet.

Longueur

56,5 cm

Largeur

17,8 cm

Hauteur

37,0 cm

Épaisseur

S/O

Poids

S/O

Diamètre

S/O

Volume

S/O

Lexique

Groupe

Météorologie

Catégorie

Mesure de vitesse et direction du vent de surface

Sous-catégorie

S/O

Fabricant

Ou

Young

Pays

United States of America

État/province

Michigan

Ville

Traverse City

Contexte

Pays

Canada

État/province

Inconnu

Période

1990 - 2004; this example is hand marked 2003; this instrument was apparently in use for six years (Ref. 6)

Canada

An example of an instrument used for measuring wind speed by the Meteorological Service of Canada at observing sites across Canada. The RM Young Wind Monitor is used at most of the datalogger based automatic weather stations and on all buoys amounting to hundreds of installations in Canada. The Wind Monitor has been used since 1990 and in 2004 was the most widely used anemometer in the service (Ref. 1). This example is hand marked 'Hurricane Isabel', which affected Lake Ontario and Ontario in September 2003 (Ref. 5). Part of a large collection of meteorological instruments acquired from the Meteorological Service of Canada (previously Atmospheric Environment Service) by the CSTM since 1967. MSC is the government agency responsible for collecting and disseminating meteorological data and forecasts in Canada. It was founded in 1871 in Toronto where it is still headquartered. The MSC was originally on the University of Toronto downtown campus but moved to Downsview in 1971 on land owned by UofT. The headquarters houses laboratories, research facilities and calibration and instrument maintenance facilities (now largely contracted out).

Fonction

An instrument that measures wind speed by means of a rotating propeller and wind direction by means of a wind vane, transmitting the data to a separate indicator.

Technique

An example of a propeller type anemometer, still available for purchase in 2006 (Ref. 4). The wind speed sensor is a four blade helicoid-shaped propeller. Propeller rotation produces an AC sine wave voltage signal; the frequency is directly proportional to the wind speed. The AC signal is induced in a transducer coil by a six-pole magnet mounted on the propeller shaft. The wind direction sensor is a vane with a sufficiently low aspect ratio to assure good quality fidelity in fluctuating wind conditions. Vane angle is sensed by a precision potentiometer, the output voltage is directly proportional to vane angle (Refs. 3-4). It is called a ‘prop and vane' anemometer because it has a propeller on the front of a vane that directs the propeller into the wind. With the passage of 29 cm of air the prop will rotate once and will produce three alternating pulses. The speed error is accurate to ±0.6 mph up to 30 mph and ±2% above that to a maximum of 134 mph. The propellers distance constant (the 63% response distance) is 2.7 metres. A 360 degree potentiometer measures the wind direction with an error of ±3 degrees. There is a blank section called a 'deadband' between 355 and 360 degrees that has to be removed by processing. This is possible because surface wind direction will vary continuously over a range of 20 to 40 degrees. Also to remove direction ambiguities caused by averaging, the N-S and E-W vectors are calculated and all subsequent computations are done on these vectors. This causes some errors at very low wind speeds. Prop and vane anemometers suffer from the yaw error. This is caused when a gust occurs because the direction of a gust veers about 30 degrees from the general surface wind and the vane cannot respond in time. The speed will also be reduced slightly since the direction of the gust is off the main axis of the propeller. These anemometers are also more susceptible icing than cup anemometers (Ref. 1).

Notes sur la région

Inconnu

Détails

Marques

white lettering on black ground on either side of vane reads"YOUNG' / beige and black label on junction box reads "[logo]/ YOUNG'/ incised lettering on junction box reads '40380'/ handwritten lettering on vane reads 'FM 45148/ C.O.. WOODS/ DEC 05/03/ 1st YEAR RS' and '40380/ FROM 45159/ DEC 08/03/ HURRICANE/ ISABEL REPL.'

Manque

appears complete

Fini

white vane and body/ black head, propeller, shaft, junction box/ plated clamp

Décoration

S/O