On May 23, 2014, at 11:12 PM, Mark Sims hol...@hotmail.com wrote:
The nice thing about measuring temperature via sonic measurements is that the
measurements are unaffected by solar heating of the apparatus... it does not
need to be in the shade.
I stumbled on this paper a while back when I
I ran across this very issue when trying to calibrate my barometer chip against
the NWS station located less than two miles away. Their numbers for millibars
and inches of mercury do not agree. I sent them an email and asked what was
going on. They said their instruments read out in
atmospheric pressure taken for a weather observation is measured in
millibars and respresents the barometric pressure at ground level at
that location. If the instrument is located somewhere besides ground
level it will be corrected to ground level.
The value given in inches of mercury is
Here in the US, most people who really care about wind speed think
knots. For causal use to the general public them it's MPH.
If you want to be esoteric use the Beaufort Wind Scale It is
actually still used because it can be estimated from looking at the
water. It is easy to learn to tell a
In message blu170-w517a3e7d32e32be4c3d3a4ce...@phx.gbl, Mark Sims writes:
I am building a weather sensor that includes a ultrasonic anemometer
Now the question... I would like it to be able to output data in
imperial or metric units. In what units is the typical wind speed
reported
Hi Mark,
I second Paul Henning,
here in Europe we use officially the SI standard, does mean m/s and hPa!
Privately used other units are another thing like km/h or units Beaufort
and mb (millibar),
but not official. If possible use always the international SI units and
as personal choice km/h,
Hello,
Wind speed usually in meters/sec (when used for scientific data) or km/h
(used in the news, so the people can compare with car speed ;) )
Pressure in millibars. Meteorologist also usually refers to
hectopascals, but it is more for representing something at a given
altitude (for
hektopascal is pseudo-SI form, as it is a compromize between the old
milibar and propper SI unit of Pascal with suitable prefix 1 mbar = 1
hPa, but since we have normal pressure at 1013 mbar we should write it
as 101,3 kPa but not 1013 hPa if we is to follow SI all the way.
Temperature in C
Here in Canada, for many years we have officially used km/hr and
kilopascals (kPa) for all reporting (both civil and aviation). These
units are now easily understood by the general population.
Personally, for pressure I preferred hectopascals but over the years
even I have adapted to the
Hi Mark:
The key benefit of an ultrasonic wind speed/direction sensor is that it can
detect very slow wind speeds.
My Peet Bros. system does not start telling me anything until the speed is a
few MPH.
http://www.prc68.com/I/UltimeterWeatherStation.shtml
But all the weather stations I've seen
I am building a weather sensor that includes a ultrasonic anemometer to measure
wind speed, direction, and air temperature. It uses 4 cheap ($1 each) HC-SR04
ultrasonic rangefinder modules that output a pulse width proportional to the
time of flight of the sound signal (topic is time nut
For civilian use, Miles/hour and inches Hg. Aviation and marine would be
knots and inches Hg.
Tom
- Original Message -
From: Mark Sims hol...@hotmail.com
To: time-nuts@febo.com
Sent: Friday, May 23, 2014 9:16 PM
Subject: [time-nuts] Weather/units question for European members
I am
Mark
I think wind speed is also in Bueforts. Pretty sure thats misspelled.
Regards
On Fri, May 23, 2014 at 9:16 PM, Mark Sims hol...@hotmail.com wrote:
I am building a weather sensor that includes a ultrasonic anemometer to
measure wind speed, direction, and air temperature. It uses 4 cheap
Sent: Friday, May 23, 2014 18:17
To: time-nuts@febo.com
Subject: [time-nuts] Weather/units question for European members
I am building a weather sensor that includes a ultrasonic
anemometer to measure wind speed, direction, and air
temperature. It uses 4 cheap ($1 each) HC-SR04
Beaufort scale
Mark
I think wind speed is also in Bueforts. Pretty sure thats misspelled.
Regards
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I have a crappy Chinese-made handheld propeller anemometer. I'm not in
Europe but FWIW the output can be selected as: m/s, km/h, ft/min, knots
or mph. So, the first two of those seem to be likely metric choices.
Your method sounds interesting. Would you be willing to share any
details about
The project sounds like a fun hack -- I would be curious as to the resolution
you achieve with these modules.---
The best description on the net about building a sonic anemometer is one by
Hardy Lau:http://www.technik.dhbw-ravensburg.de/~lau/ultrasonic-anemometer.html
I have also built one
I am building a weather sensor that includes a ultrasonic anemometer to
measure wind speed, direction, and air temperature. It uses 4 cheap ($1
each) HC-SR04 ultrasonic rangefinder modules that output a pulse width
proportional to the time of flight of the sound signal (topic is time nut
On Saturday, May 24, 2014, David J Taylor david-tay...@blueyonder.co.uk
wrote:
Now the question... I would like it to be able to output data in imperial
or metric units. In what units is the typical wind speed reported
(meters/sec, km/hour, ?). Also air pressure (millibars/hectopascals/
On Sat, 24 May 2014 01:16:32 +, Mark Sims wrote:
Now the question... I would like it to be able to output data in
imperial or metric units. In what units is the typical wind speed
reported (meters/sec, km/hour, ?). Also air pressure
(millibars/hectopascals/pascals/?).
Our weather
There is a great sonic anemometer in:
An inexpensive sonic anemometer for eddy correlation G.S.Campbell and
M.H.Unsworth, (1979), Journal of Applied Meteorology Vol 18, August 1979, Pp.
1072-1077.
This unit uses 4000 CMOS, a LM301A and two cheap ultrasonic transducers. It
operates a
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