Vaisala WAT12 Technical data

WAT12 Analog Wind Transmitter

e WAT12 is designed to convert the wind speed and direction data measured into
two analog current loop signals.

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

Tel: [phone]

Fax: [phone]

Email: [e-mail]

www.vaisala.com/WAT12

Features/Benefits

• Converts the digital data supplied

by the Vaisala Wind Set 15 and
the Vaisala Wind Set 25 into two
industry standard analog current
loops; one for speed, the other for
direction

• Selectable loop current

• Suitable for nearly any input type

• Wide range of input power

• provides the sensors with a

throughput for optional heating
power.

e Vaisala Wind Transmitter WAT12
is an economic solution to a standard
interface between Vaisala's wind
sensors and analog panel meters,
chart recorders, digital LCD or LED
displays, data loggers, computers with
analog inputs, etc. e transmitter
converts the wind speed and direction
data measured by either Vaisala Wind
Set WA15 or Vaisala Wind Set WA25
into two analog current loop signals,
respectively. e power to the sensors
is also supplied through the WAT12
unit.

e WAT12 consists of a PC board unit
in a junction box and a cross arm for
mounting the wind sensors. A 4-wire
cable for the wind speed and direction
signals and power supply is needed
between the transmitter and the
receiving end.

User selectable loop
current

e loop current is selectable of, e.g.,
4 ... 20 mA, 0 ... 10 mA, and 1 ... 5 mA.
e loops are supplied by high-side
drivers with a return to the signal &
power ground; thus nearly any input

type can be driven.

e transmitter accepts a wide range
of input power, i.e. 12 ... 28 VDC. With
5 mA loop current selected, the total
current consumed is less than 40 mA
(including the sensors and the loop
current), hence making it possible to
remotely supply the operating power
from a distance of several kilometers,
even through private or leased
telephone lines.

Optional heating power

e WAT12 also provides the sensors
for throughput of optional heating
power. e heating power connection,
if required, calls for an extra pair of
wires. Since the heating elements
typically consume some 500 mA, the
heating power is most conveniently
supplied from a local power source.
A thermostat switch is optionally
available for automatic connection of
heating power below +4 °C (+39.2 °F).

128

Vaisala Instruments Catalog 2008

Ref. B210712en rev. A

WAT12

Technical Data

WIND

Digital-to-analog current loop converter for Vaisala wind sensors

Signal input from sensors

Wind direction 6-bit parallel GRAY code
(optionally 7 bits)
Wind speed Pulse frequency 0 ... 750 Hz

Output signals

Two analog current loops, one for direction, one for speed. High­side drivers; the loops return to the common signal & power ground.
Loop driving voltage 10 V typ.

Output accuracy Better than 1% of full scale
Loop current options 0 ... 5 mA; 1 ... 5 mA
(jumper selectable) 0 ... 10 mA; 2 ... 10 mA
0 ... 20 mA; 4 ... 20 mA
Max. loop resistance 1800 ohm for 5 mA loop
900 ohm for 10 mA loop
450 ohm for 20 mA loop
(incl. cable resistance + receiver's input resistance)

Full scale options (jumper selectable)
For direction 0 ... 360°/0 ... 540°
For speed 0 ... 51.2 m/s / 0 ... 76.8 m/s
Signal cable 4 wires minimum (Vin+, Vin–, DOP, SOP)

General

Input operating power 12 ... 28 VDC, 30 mA
Output sensor power
On-board regulated to 10.7 VDC typically
Temperature range
operating –55 ... +55 °C (-67 ... +131 °F)
storage –60 ... +70 °C (-76 ... +158 °F)
Humidity 0 ... 100 %RH
Material
Cross arm AI anodized
Junction box AI painted grey

Complies with EMC standard EN 61326-1:1997 + Am1:1998 +
Am2:2001; Generic Environment

Dimensions

PC board 114 × 69 mm2
Junction box 125 (w) × 80 (h) × 57 (d) mm
Cross arm length 800 mm

Mounting to a Ø 60 mm pole mast
Weight 1.5 kg

Vaisala Instruments Catalog 2008

Ref. B210712en rev. A

Specications subject to change without prior notice.
©Vaisala Oyj

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