Air Temperature and Relative Humidity

Our weather station includes two probes in this cylinder, each small but powerful. One measures relative humidity by measuring the ratio of water in the air using a thin film polymer sensor. If there is a high humidity rating, we feel hotter outside in the summer and colder in the winter. The other probe measures actual temperature with an electronic thermometer. Both probes are protected by a radiation shield, and send information to the museum's website and the National Weather Service sites.

Anemometer

Our weather station uses an ultrasonic wind sensor device to measure wind speed and direction. It measures wind velocity based on the time it takes for sonic pulses to travel between pairs of transducers. Sonic anemometers can take measurements with great precision, 20 Hz or better, which make them well suited for automated weather stations since they have no moving parts.

Barometer

Our weather station uses a Vaisala Pressure Sensor PMT16A .

A barometer measures air pressure. Air pressure and differences in pressure are among the most important weather makers. The centers of storms are areas of relatively low air pressure, compared to pressures around the storm. High air pressure generally brings good weather. A rising barometer indicates increasing air pressure; a falling barometer indicates decreasing air pressure .

Current Weather Detector

One of the most high tech devices on our weather station is the current weather detector. It measures visibility conditions up to 6500 feet, and has the capability to detect four different types of precipitation (rain, drizzle, mixed rain/snow, snow), as well as fog, mist, haze, or clear conditions.

Lightning Rod

The lightning rod is used to protect the weather station from a lightning strike which could harm the sensitive electronic instruments. The lightning rod is attached to a heavy copper wire which is connected to a six-foot-long copper rod driven into the ground near the station. If lightning does hit the lightning rod it is directed into the ground where it is dissipated harmlessly, protecting the weather station instruments.

Radiation Shield

This round instrument that looks like a stack of cereal bowls is actually a radiation shield that protects the humidity and temperature probes from the direct sunlight and rain. The actual probes are located inside the shield.

Rain Gauge

Our station uses a tipping bucket to measure rainfall and other forms of precipitation. At the top of the cylinder is a funnel that collects and channels the precipitation. The precipitation falls onto one of two small buckets or levers which are balanced in the same manner as a scale or child’s seesaw. After a measureable amount of precipitation falls into the funnel, the lever tips and an electrical signal is sent to the recorder. The total amount of precipitation is calculated by counting the number of times that the bucket tips. The device can also measure snowfall. Snow in the funnel is melted by a special heater and the resulting water drains into the tipping bucket assembly.

Snow Depth Sensor

Our weather station uses an ultrasonic transducer to measure the amount of snow on the ground. An ultrasonic transducer is a device that converts energy into ultrasound, or sound waves above the normal range of human hearing. By sending a sound wave toward the ground, and then listening to how long it takes to bounce back, it is possible to determine the distance to the ground, or in this case, the snow. By comparing the measurement at frequent intervals, we can determine the rate of snowfall, as well as the amount of snowfall in the past day or hour.

Transmitter Antenna

Our weather station collects data and transmits it to the Museum every minute using a special two-way radio and stored on a computer. Once the data is stored on the computer a special program uses the Internet to send information to the National Weather Service and the Museum’s website.