Peet Bros Ultimeter 2000 Weather Station

Weather Sensors

ANEMOMETER

The wind sensor is an all-digital design containing two magnetic switches. Each switch opens and closes once each time the cups go around. Wind speed is calculated by measuring the time between consecutive pulses from one switch. Wind direction is determined by measuring the relative timing between pulses from the two switches. North is indicated when the two sets of pulses exactly coincide. South is indicated when pulses from one switch occur exactly midway between consecutive pulses from the other switch.

Features:

• Extremely Reliable
• No friction contacts to wear out
• Elegantly simple for longevity and reliability
• Top quality electrical components - two ultra-reliable, glass enclosed, hermetically sealed, magnetically operated reed switches
• Top quality mechanical components - UV resistant Lexan(c) molded parts, corrosion resistant bearings with Delrin races and surgical stainless steel balls that can be taken apart and reassembled for cleaning, if necessary, without tools and without affecting accuracy.
• Digital pulse data - resists electrical interference from radio transmitters or other sources
• Can operate over long distances with full accuracy, thanks to all-digital design.

Its heater is thermostatically controlled and draws a maximum of only 0.8 watt. It is powered directly from the standard junction box of the ULTIMETER 2000 using a six conductor cable for both heater power and wind speed and direction signals.

BAROMETRIC PRESSURE SENSOR

The barometric pressure sensor is a precision solid state electronic device, housed within the keyboard/display unit. A quartz membrane over an evacuated chamber flexes as the air pressure changes. Resistance elements on the membrane translate its flex into voltage levels that are converted to digital signals and sent to the microprocessor.

Features:

• Readings are stable because each sensor is individually temperature compensated.

• You can use the system at altitudes from sea level to 15,000 feet without factory

recalibration.

• Pressure changes are shown as numeric values - not just with directional arrows.

• Pressure changes are determined over a full 3 hour interval.

• Pressure change data is updated every 10 minutes.

• The barometric pressure change alarm can be set for rising or falling pressure.

• There is a built-in preset Storm Alert feature. If the pressure falls more than 0.18 inches of

mercury in 3 hours, the barometer symbol will flash when pressure is displayed.

*This is a solar radiation shield which houses both a temperature and humidity sensor. Its purpose is to shield the temperature sensor from direct contact with the sun allowing for a more accurate outdoor temperature reading.

OUTDOOR TEMPERATURE SENSOR

A precision aged metal-oxide thermistor is used to measure temperature. As the temperature increases, its electrical resistance decreases, changing a signal voltage that is first converted to digital form, then sent to the microprocessor.

Features:

• Each sensor is precision calibrated for complete interchangeability.

• Each sensor is specially aged to assure long term stability.

• The microprocessor is programmed to make minute corrections over the specified

temperature range, further enhancing the resultant accuracy.

• No user calibration is required or provided for, because of the precision interchangeability

of the sensor elements, even in the event of sensor replacement.

OUTDOOR HUMIDITY/TEMP SENSOR

The Humidity Sensor utilizes precision thick film polymer capacitance device. The sensor is used in a low frequency oscillator circuit, which changes frequency as the relative humidity changes. The output of the oscillator is fed into the microprocessor. The exceptional long-term stability of the humidity sensor element means years of use without recalibration.

Features:

• It is accurate from 0% R.H. to 100% R.H. Others are typically said to be accurate from

10% to 90% or even 20% to 80% R.H.

• Unlike others, our humidity sensor will not be damaged by prolonged high humidity. In

fact it's so rugged, it could even be totally immersed in water without damage!

DEW POINT

Dew point is measured by the Outdoor Humidity/Temp Sensor. The dew point temperature is derived from the outdoor temperature and relative humidity measurements.

WIND CHILL

Wind chill temperature is measured by the Wind Sensor and Outdoor Temperature Sensor. It is calculated from wind speed and outdoor temperature measurements by the weather station.

"PRO" RAIN GAUGE

The "PRO" Rain Gauge features superb accuracy and extraordinary reliability. Although it empties itself automatically, it has absolutely no adjustments and no moving parts - the long term accuracy and reliability are molded in! Operating on a drop-counting principle, the PRO Rain Gauge senses every one-thousandth inch of rain and reports each one-hundredth inch back to the ULTIMETER Weather Station. In spite of its amazing resolution, the PRO gauge can handle "world record" class rain rates of more than 10 inches per hour!

The Pro Rain Gauge is 5 1/8" high and has a maximum diameter of 4 1/2". It can mount directly on a 1" pvc post or on an optional universal mounting bracket. The PRO Rain Gauge comes with a 40 foot, 4-conductor cable that makes power and signal connections to the junction box of an ULTIMETER 2000 Weather Station.

Accuracy of the PRO gauge starts with its exclusive parabolic funnel that traps wind driven rain so it won't splash out. Rain is funneled into a precision drop forming tube, much like those you'd see in a hospital IV bottle. Each uniform drop coming out of the tube is equivalent to exactly 0.001 inches of rain. Each uniform drop falling from the tube is detected by four gold plated sensing electrodes that signal an electronic counting circuit. After each ten drops this circuit sends a signal to the ULTIMETER keyboard indicating that another hundredth  inch of rain has fallen.