NCAR Weather Station Sensor Specifications


Barometer

The barometer is a monolithic piezo-resistive device with lazer-minimal temperature compensation.
Range:
600 to 1100 millibars
Resolution:
1 millibar reported
Accuracy:
3 millibars
Operation Temperature:
-40 to 85 Degrees C
Compensated Temperature:
0 to 50 Degrees C
In Accuracy Specification:
0 to 50 Degrees C

Humidity Sensor

The humidity sensor is a Vaisala Humicap thin film device.
Range:
0 to 100% Relative Humidity
Accuracy at 20 degrees Celcius:
+/- 2 percent (0 to 90% RH)
+/- 3 percent (90 to 100% RH)
Temperature Coefficient:
+/- 0.04% RH/Degree C
90% Response Time:
15 seconds
Long Term Stability:
< 1% RH/year

Temperature Sensor

The temperature sensor is a powder metal oxide thermistor device.
Range:
-50 to +50 degrees Celsius
Accuracy:
+/- 0.15 degrees Celsius
Time Constant:
3.0 seconds

Wind Sensor

The wind sensor is an R. M. Young prop-vane device with a helicoid propeller.
Range:
0 to 60 meters per second (0 to 134 miles per hour)
Threshold:
1.0 meters per second (2.2 miles per hour)

Rain Gauge

The rain gauge is a Texas Electronics Inc TR525I tipping bucket collector. With all tipping bucket rain gauges, there may be some inaccuracy at the beginning of a rainfall event as the collection funnel gets wet. Partially full buckets also account for some inaccuracy at the beginning and end of a rainfall event. We are not currently heating the rain gauge so snowfall will show up after the event when the temperature warms up enough to thaw the snow, and the amount reported may be inaccurate due to overflow of the collection funnel and wind effects. The Rain Accumulation data is reset to zero every day at midnight.
Resolution:
0.01 inches reported per tip
Accuracy:
1% at 2 inches/hour or better
Temperature Limits:
0 to 50 Degrees C
Humidity Limits:
0 to 100 percent C
Receiving Orifice Diameter:
15.4 cm (6 inches)