Vaisala WS425F, WS425G Technical data

P.O. Box 26, FI-00421 Helsinki, FINLAND

Tel: [phone]

Fax: [phone]

E-mail: [e-mail]

www.vaisala.com

e ice-free WS425 F/G meets the standards of the US National Weather Service.

Features/Benefits

• Premium, ice-free sensor for most
demanding weather conditions

•

Enhanced 150 W heating to ensure
ice-free operation

• Wide measurement range up to 165
knots

• Highly accurate up to 125 knots

• Maintenance-free

• Superior data availability secured
by Vaisala patented WINDCAP®
technology

• Triangular shape prevents wind
interference between transducers

• Wide operating temperature range

-62 ... +55 °C (-80 ... +130 °F)

• Large transducer heads are
insensitive to rain

• Optical cable modem, RS-232 for
service mode

• Field verification device available

• US National Weather Service relies
on Vaisala WINDCAP® technology

WS425 F/G for harsh
conditions

e WS425 F/G models are special
ice-free versions of the standard
WS425 family. With its exeptionally
high heating power of 150 W, the
WS425 F/G is suitable for most
demanding conditions.

Initially, these models were designed
to interface with the network of
the Automated Surface Observing
System (ASOS), the primary surface
weather observing network in the
United States.

Maintenance-free

e WS425 F/G has no moving parts,
and it is resistant to contamination
by salt, dust, and corrosion. In
addition to improving accuracy and
the reliability of data in all wind
conditions and climates,
the WS425 F/G requires no
on-demand or periodic maintenance.

Measurement based on
ultrasound

e WS425 F/G uses ultrasound to
determine horizontal wind speed
and direction. e measurement is
based on a transit time, the time
it takes for the ultrasound to travel
from one transducer to another,
which depends on the wind speed.

e transit time is measured in
both directions for each pair of
the transducer heads. Using two
measurements for each of the three
ultrasonic paths at 60° angles to each
other, the WS425 F/G computes the
wind speed and direction.

e wind measurements are
calculated in a way that completely
eliminates the effects of altitude,
temperature, and humidity.

Heating

To secure operation in the most
difficult conditions, the sensor has an
enhanced heating feature with a total
heating power of 150 W. e heater
foils are placed inside the ceramic

WS425 F/G Ultrasonic Wind Sensor

transducers, the transducer arms,
and the bird spike.

e heating control is located in the
power supply module, an integral
part of the delivery.

ASOS compatibility

e WS425 F/G includes a 10-meter
sensor cable, a power supply with a
heating control circuitry, and power
relays to control the heating current.

e optical modem that isolates the
sensor from the host system allows
for safe communication.

e mounting tube, cable assembly, and an adapter for F/G
models.

Technical Data, Dimensions

Ref. B210527EN-A 2006-10

Wind

Wind speed

Range 0 ... 165 knots
Starting threshold virtually zero
Delay distance virtually zero
Resolution 0.1 knots
Accuracy (range 0 ... 125 knots) ±0.26 knots

or +/-3 % of reading, whichever is greater

Wind direction

Range 0 ... 360°
Starting threshold virtually zero
Delay distance virtually zero
Resolution 1°
Accuracy
(2 knots < wind speed < 0 ... 125 knots) ±2°

Outputs

Communication media Optical cable,

RS-232 for service
Message format ASOS compatible
Baud rate 2400, 4800, and 9600
Available averages 1 ... 30 s
Response time
(continuous measurement)

1 s

WINDCAP® is a registered trademark of Vaisala.
Specifications are subject to change without prior notice.
© Vaisala Oyj

General

Operating voltage

115 VAC/60 Hz or 240 VAC/50 Hz
Power consumption
(max. heating)

150 W
Operating temperature -62 ... +55 °C (-80 ... +130 °F)
Material

body, arms, power stainless steel
tranducer heads silicone rubber

Sensor dimensions

height 350 mm
width 250 mm
depth 286 mm
weight 1.7 kg

Power dimensions

height 340 mm
width 342 mm
depth 165 mm
wieght 12.5 kg

Approvals CE

Accessories

Power supply WS425PowerUS, WS425PowerEU
Cable 4253100
Installation kit for ASOS 4257100
Field verifier WS425VERIFIER

WS425 F/G

WIND