Note: Be sure to remove the rubber tube and rubber plug from the top of the barometer tube.
These are only present during shipping to prevent spillage of the red fluid.
-Barometer U-shaped tube with red fluid
-Thermometer tube filled with blue fluid
-Tendency Dial – tracks pressure changes
-Hygrometer – measures relative humidity
On December 23, 1818, Alexander Adie, an optician from Edinburgh, received his patent for an invention: the Sympiesometer. He named his invention using the Greek words “sumpiesometer” (pressing together) and “metron” (measure). His instrument proved to be a reliable weather predictor. We constructed, according to his patent, a completely new series of very special weather instruments: The Tendency Barometer
A Tendency Barometer consists mainly of two parts: A U-shaped tube (red fluid) and a thermometer (blue fluid). The red fluid rises or falls according to changes in air pressure. The U-shaped tube is also influenced by temperature, that is the reason why the combination with the thermometer is required. All temperature deviations during the reading of the pressure tendency will be corrected. All you need to do is to compare the level of the red fluid to the blue fluid. The difference between both fluid levels (use the Celsius scale to take difference readings) is set with the pointer on the Meteo-tendency scale. The changes in air pressure can be easily observed and an accurate forecast made.
Example: When the red fluid is 6 lines below the blue fluid. -6 (remember, use the Celsius scale to take the difference) the weather forecast is for Fair Weather. When the red fluid is 8 lines above the blue, +8, the forecast is Rainy or Stormy.
When the red and blue fluid levels are equal, the weather condition is Change.
Red fluid below the blue fluid, Good Weather (high pressure).
Red fluid above the blue fluid, Bad Weather (low pressure)
DD Barometer Main Page 
