Author Topic: Barometer and Wind Speed  (Read 1871 times)

0 Members and 1 Guest are viewing this topic.

Offline Ryan Hothersall

  • Senior Contributor
  • ****
  • Posts: 160
    • My Stuff on the Web
Barometer and Wind Speed
« on: May 12, 2009, 08:40:02 PM »
Was looking at the spec sheets on the Davis site and was wondering what type of barometer is in the console. Is it an aneroid type or something else?.

Secondly I see the wind speed is displayed as a whole number on the console, but is shown as a decimal ie 3.2 in weatherlink. The speed on my station is set to kph.

Offline wxtech

  • Weather Equipment Technician
  • Forecaster
  • *****
  • Posts: 1698
  • USAF Weather Equipment Maintenance Tech (retired)
    • Lexington, Ga. Weather
Re: Barometer and Wind Speed
« Reply #1 on: May 12, 2009, 10:07:54 PM »
Was looking at the spec sheets on the Davis site and was wondering what type of barometer is in the console. Is it an aneroid type or something else?.
semiconductor piezoresistive, my guess; which would function like aneroid in that pressure differences between chambers causes a diaphram to move. 
It's similar to this one, but with one tube, approx dimensions .56" x .56" x .5"
« Last Edit: May 13, 2009, 12:18:06 AM by wxtech »
Al Washington, Lexington, Ga.,  NWS Coop station=LXTG1, Fischer Porter, SRG, MMTS. 
CoCoRaHS=GA-OG-1. CWOP=CW2074.  Davis VP2+ WLIP 5.9.2, VP(original) serial, VWS v15.00 p02. ImageSalsa, Win7 & Win8 all-in-one.

Offline dalecoy

  • Forecaster
  • *****
  • Posts: 6360
    • Lee's Summit, MO
Re: Barometer and Wind Speed
« Reply #2 on: May 12, 2009, 11:42:42 PM »
Was looking at the spec sheets on the Davis site and was wondering what type of barometer is in the console. Is it an aneroid type or something else?.

Secondly I see the wind speed is displayed as a whole number on the console, but is shown as a decimal ie 3.2 in weatherlink. The speed on my station is set to kph.

There are exactly two types of barometers that are "affordable".  One uses a column of fluid, and typically would use mercury.

Mercury barometers are inherently about 32 inches tall.  And they present some hazards. 

The other type is aneroid.  That's what you have.

============

Your observations about the display of wind speed are "the way it is".

Offline Ryan Hothersall

  • Senior Contributor
  • ****
  • Posts: 160
    • My Stuff on the Web
Re: Barometer and Wind Speed
« Reply #3 on: May 13, 2009, 08:27:34 AM »
Was looking at the spec sheets on the Davis site and was wondering what type of barometer is in the console. Is it an aneroid type or something else?.

Secondly I see the wind speed is displayed as a whole number on the console, but is shown as a decimal ie 3.2 in weatherlink. The speed on my station is set to kph.

There are exactly two types of barometers that are "affordable".  One uses a column of fluid, and typically would use mercury.

Mercury barometers are inherently about 32 inches tall.  And they present some hazards. 

The other type is aneroid.  That's what you have.

============

Your observations about the display of wind speed are "the way it is".

So which one is showing the proper wind speed?

Offline dalecoy

  • Forecaster
  • *****
  • Posts: 6360
    • Lee's Summit, MO
Re: Barometer and Wind Speed
« Reply #4 on: May 13, 2009, 10:20:56 AM »
Was looking at the spec sheets on the Davis site and was wondering what type of barometer is in the console. Is it an aneroid type or something else?.

Secondly I see the wind speed is displayed as a whole number on the console, but is shown as a decimal ie 3.2 in weatherlink. The speed on my station is set to kph.

Your observations about the display of wind speed are "the way it is".

So which one is showing the proper wind speed?

Both are showing the "proper" wind speed.

Is your question about "whole numbers versus decimal"?  Or about "console versus weatherlink"?

Offline Ryan Hothersall

  • Senior Contributor
  • ****
  • Posts: 160
    • My Stuff on the Web
Re: Barometer and Wind Speed
« Reply #5 on: May 13, 2009, 06:45:33 PM »
I was wondering why both the console and weatherlink show either whole or decimal numbers.

Offline dalecoy

  • Forecaster
  • *****
  • Posts: 6360
    • Lee's Summit, MO
Re: Barometer and Wind Speed
« Reply #6 on: May 13, 2009, 08:04:56 PM »
I was wondering why both the console and weatherlink show either whole or decimal numbers.

Oh.  You'll have to ask Davis. 

I could speculate that the console wind speed, because it uses large digits, didn't have room for decimals - while the WeatherLink displays just use small digits.

But "why" questions have to be answered by the designers.

 

anything