Make A Spring Gauge Wind Anemometer From Cardboard USA 1910

3 Pages·1910·0.03 MB·English

Jf the loan of an anemometer cannot be ch-
tsined, a simple form af wind-pressure meter
should be used to determine the right weight
fixe. 49) required ww jast hold the windrnill
sails at the velocity decided upon. Such an
apparatus is sketched in fig. 76, Lt is mercly a
sheet of stout, carfbourd. 2 feet X 1 font, bung
‘an one of the narrow edges by a hinge of linen,
the middle of the lower edge being connected
as shown to a sma‘l spring letter balance capa-
hile of reading up to at Ieest one pound, A tabte
of wind-pressures and velecities is given helow,
by whieh any pressure registered can be con
verted int velacity, The pressure-board mst,
of course, squarely face the wind lowing at the
time of the cxperiment. Note that the spring
valance is just at zero when no wind fs ime
pressed on the buard. ur a false reading may
be obtained. Af made to the given sizes, the

Fig 70—-A. Siete Wind-pre

sore Gauge.

readings will he direct measurements of the
pressure per sare foot.

The brake harse-perwer of a windmill can he
taken in exactly the same way as that of a
s‘camengine, the only diffieutty being the asual
tradiness of the wind. At a time when the
nd is fairly steady and about right in velocity,
such a test should be made, one observer wateb-
ing the pressure-mcter and noting the pres

say, every half-minute, another reading the
spring balance of the brake at similar intervals,
the test lasting for a quarier of an hour. Aver-
age results may then be obtained, which may
be exiromely useful for determining the size of
dynamo required. it being remembered that the
power of the wind varies (thearetically) directly
as the cube of its velocity. In practice the vari-
ation rate lies between this and the square of the
velocity.

‘Trot of Woro Purser as Vevociries,
se

ies pe| Poster | Feet per TE eg
jour | caine, | second. 1 tbe, rer | Deveription,
es A faq. toot
1] 8 as ere
2 | ue 2] gun pecepe
| Gente biewe
ob) ae | {
bl as| 2 Plenent bree
|) Be
B | ne) 2 Sik gale
| dea | 4 | fare
| jos | a High wind,
# | eal & Wary high wind
% ) ae | $s. stom.
wo | se | fe 3
io | si | 02 {| Great storm,
| Sap | ae

Huricane