Digital Anemometer Master

Digital Anemometer

An anemometer measures the speed of moving air, most often wind speed. You will be using it to calculate the speed of air moving through a vent.

Operating Instructions

1. Turn the anemometer on by depressing and holding the “mode” button. The device should power up in a few seconds. 2. To change the units for measuring wind speed, depress and hold the “mode” button until the speed unit flashes. 3. Depress “set” to get the desired wind speed unit. 4. To change from ºC to ºF or vice -versa, remove the yellow cover from the device, turn it over, and use a push-pin or straightened paper clip to depress the “C/F” button on the back. 5. The device will also show the Beaufort Scale for the wind speed, as a series of pointed blocks stacking upon each other.

BEAUFORT NUMBER

NAME OF WIND LAND CONDITIONS

0 Calm Smoke rises vertically 1 Light air Direction of wind shown by smoke drift but not by wind vanes

WIND SPEED (MPH)

Less than 1 1 - 3

2 Light breeze Wind felt on face, leaves rustle, ordinary wind vane moved by wind 3 Gentle breeze Leaves and small twigs in constant motion, wind extends light flag 4 - 7

8 - 12

4 Moderate breeze Wind raises dust and loose paper, small branches move 13 - 18

5 Fresh breeze Small trees and leaves start to sway 6 Strong breeze Large branches in motion, whistling in wires, umbrellas used with difficulty 7 Near gale Whole trees in motion, inconvenient to walk against wind 8 Gale Twigs break from trees, difficult to walk 9 Strong gale Slight structural damage occurs, shingles and slates removed from roof 19 - 24 25 - 31

32 - 38

39 - 46 47 - 54

10 Storm Trees uprooted, considerable structural damage occurs 55 - 63 11 Violent storm Widespread damage 64 - 63 12 Hurricane Widespread damage, devastation Greater than 72

What is the Beaufort Scale?

In 1805, Sir Francis Beaufort of the Royal Navy developed the scale to help sailors estimate wind speed for settings sails based on visible effects of winds. The scale describes wind effects seen on land or at sea and assigns a value of 0 to 12 according to the force applied by the wind. The higher the number, the stronger (faster) the wind.

Portrait by Stephen Pearce of Sir Francis Beaufort; c. 1855-1856, oil painting