Measuring Wind DirectionWith A Map Compass

Tools For Pesticide Applicators

Larry SchulzePesticide Education Specialist

University of Nebraska- Lincoln Extension

Wind Direction & Velocity• Have strong impact upon

pesticide applications• Influence the ability to damage

sensitive / off target areas• Drift is a primary regulatory

compliant and concern

Determination of Wind Direction

• What direction is the wind?

• Example: South

• What is the possible impact of the use of a very general wind direction such as “south”?

Determination of Wind Direction

• In a court of law, a “south” wind–May be construed to be anything

just south of east through just south of west

–About 170 degrees

–“South” is not accurate

–Be more exact

What DirectionIs The Wind?

• North?

• Northeast?

• East?

• Southeast?

• South?

• Southwest?

• West?

• Northwest?• With 360 degrees in a circle– There are 45 degrees in each

selection of the above directions– This is still not specific enough

Wind Direction• It’s crucial to accurately record

the wind direction–For good application records• It’s not required, but recommended

–To protect one’s actions–To reduce potential liability

Compass Exercise• To acquaint applicators about a

compass..–To measure wind direction

–To manage drift

–To protect sensitive areas

–For accurate records

Map Compass

As an example………Click here for Coghlan’s Web site

See “Products Listing,” then “Compasses” Product No. 8162

Parts of a Compass

Orientation Arrow

Red Needle (points to magnetic North)

Black Arrow Outline

Rotating Dial

Measuring Wind Direction

• Hold compass flat and level

• Point red arrow on plastic base into the wind

Measuring Wind Direction

• Observe red needle with green tip points to magnetic North

• Turn compass dial until black arrow outline is under the red needle

Measuring Wind Direction

• Read wind direction in degrees at base of red arrow

• 45 degrees (a northeast wind)

Compass Guidelines• Always hold

compass level

• Use compass away from metal

• Do not use in tractor cabs

Vendors• Sporting goods

stores

• Tackle shops

• Hardware stores

• Price about $5.00