4 supplies for power and communications options, 5 determining true north for wind vane orientation, Supplies for power and communications options – Campbell Scientific ET107 Evapotranspiration Monitoring Station User Manual

Page 16: Determining true north for wind vane orientation

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ET107 Weather Station

Wire strippers

Pocket knife

Calculator

Volt / Ohm Meter

Electrical Tape

Step ladder (6 ft)

Station manuals

Station log and pen

Open end wrenches: 3/8 in, 7/16 in, 1/2 in, 9/16 in, 15/16 in

Socket wrench and 7/16 inch deep well socket

Adjustable wrench

Pliers

Conduit and associated tools (as required)

Felt-tipped marking pen

Claw hammer

Pipe wrench (12 in)

1.4 Supplies for Power and Communications Options

AC Power

Wire, conduit, and junction boxes as needed (see FIGURE 2-1).

User supplies valve box at base of station and weatherproof

enclosure for transformer. See FIGURE 2-1.

Phone Modem

Phone modem at the central computer.

Dedicated single twisted pair with shield phone line to the weather station

valve/junction box (see FIGURE 2-1).

Short-Haul Modem

Direct burial cable with a minimum of 2-twisted pairs with shield (minimum 5

conductors total) to travel from the weather station to the central computer

junction box. Direct burial armored cable may be required for rocky soils or

rodents (Anixter pn F-02P22BPN (phone 847-677-2600)) or equivalent type

cable (see FIGURE 2-1).

RF450

Antenna for the ET107 station (pn 14205 Yagi antenna recommended). PS24

Power Supply and pn 18520 Hanger Kit if not using ac power (see Appendix

B, PS24 24 Ahr Power Supply and 10 x 12 inch Enclosure).

1.5 Determining True North for Wind Vane Orientation

Magnetic declination, or other methods to find True North, should be determined

prior to installing the weather station. True North is usually found by reading a

magnetic compass and applying the correction for magnetic declination*; where

magnetic declination is the number of degrees between True North and Magnetic

North. The preferred method to obtain magnetic declination for a specific site is to

use a web calculator offered by NOAA (Section 1.5.1, Web Calculator). The

magnetic declination can also be obtained from a map or local airport. A general

map showing magnetic declination for the contiguous United States is shown in

FIGURE 1-6.

NOTE

6

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