USGS Home
Contact USGS
Search USGS

CLIMET Station

Any use of trade, product, or firm names in this web site is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Scroll down page to read descriptions of CLIM-MET station parts, or click links in list below: Marble dust trap Airfoil "frisbee" dust collector Pyranometer Radio telemetry system Wind speed/direction Air temperature and relative humidity Temperature gradient sensor Power module Datalogger Rain gauge BSNE field dust sampler SENSIT erosion monitor Soil moisture

1. Marble Dust Trap

The design consists of a single-piece Teflon-coated angel-food cake pan painted black on the outside and mounted on a steel fence post about 2 m above the ground. A circular piece of 1/4-inch-mesh stainless-steel mesh is fitted into the pan so that it rests 3-4 cm below the rim, and glass marbles fill the upper part of the pan above the mesh. The Teflon coating is nonreactive and adds no mineral contamination to the dust sample should it flake. The steel mesh resists weathering under normal conditions. The 2-m height eliminates most saltating sand-sized particles. The marbles simulate the effect of a gravelly fan surface and prevent dust that has filtered or washed into the bottom of the pan from being blown away. The empty space below the mesh provides a reservoir that prevents water from overflowing the pan during large storms. All dust traps are fitted with two metal straps looped in an inverted basket shape and the top surfaces of the straps are coated with Tanglefoot. This sticky material never dries and effectively discourages birds from roosting.

2. Airfoil "frisbee" dust collector

The shape of the collector minimizes the discriminating effects of the turbulent wake over the surface, as wind changes angle of attack.

It collects two types of samples:

1. Particles for analysis by microbeam methods, for morphology and chemical composition
2. Bulk deposition for bulk chemical analysis

3. Pyranometer

Instrument: Licor LI200X. Measures solar radiation in the Light Spectrum Waveband 400 to 1100 nm

Stability: <2% change over a 1-year period

Accuracy: Absolute error in natural daylight is +- 5% maximum: +- 3% typical

Sensitivity: 0.2 kW m-2 mV-1

4. Radio telemetry system

Mojave sites transmit data to a base station computer via a system of 900 MHz radio transceivers.

The CR10X datalogger is connected to a radio transceiver and antenna. Campbell Scientific software on a remote base station computer makes scheduled connections to the sites in the field via radio telemetry.

Equipment: Radio Tranceivers: Freewave Technologies 900 MHz FGR-115RC

Antennas: Bluewave 7 element, 10dB Gain, Yagi antenna

5. Wind speed/direction

Instrument:: Campbell model 5103

Wind speed range: 0 to 60 meters/sec

Wind speed accuracy: >+-.9 meters/sec

Wind direction accuracy: +- 3%

6. Air temperature and Relative humidity

Instrument: Campbell HMP35C

RH measurement range: 0 - 100%

RH accuracy:
+- 2%, 0 to 90%
+- 3%, 90 to 100%

AT measurement range: -35°C to +50°C

7. Temperature Gradient Sensor

Instrument: Custom USGS fabrication

Temperature gradient in degrees centigrade measured between 1 and 3 meters above the ground surface.

8. Power Module

• Modular design that can contain one or two 26 amp gel-cel batteries
• Charged by a 10 or 20 watt solar panel
• Double fuse protected
• Regulated
• Keyed plugs in power cables allow easy installation/removal of batteries without risk of shorts

9. Datalogger

Instrument: Campbell CR10X

• 12 single-ended-analog inputs, expandable with a multiplexer
• 3 excitation outputs
• 2 pulse counting inputs, expandable with a timer module

Storage module: Campbell SM716

• 716k bytes or 358k low-resolution data points
• Totally self contained, lithium-battery powered with a 2-year battery life
• Can be exchanged in the field, carried to the office to retrieve data
• Data stored as binary, converted to comma-delimited ASCII when downloaded

---

10. Rain gauge

Instrument: Campbell TE525 Tipping bucket

Range: Infinite in increments of 0.1 mm (least count)

Accuracy: 1.0% at 50.8mm/hour or less

11. BSNE field dust sampler

This is a field dust sampler suitable for collecting airborne dust under natural field conditions. The sampler orients itself into erosive winds. Samples are taken at 15, 50, and 100 cm above the ground surface.

Minimum sample height: 15mm

Efficiency: Most efficient with particle sizes above 60 microns

12. SENSIT erosion monitor

Instrument: Sensit model H7

An experimental instrument used to detect particles in saltation. The instrument's responses are:

1. [PC] A pulse train. Each pulse represents one particle impact, impacts are counted over a sampling period
2. [KE] A pulse train. Each pulse represents a fixed amount of kinetic energy, pulses are counted over a sampling period

*Unlike most sensors, the SENSIT may go for long periods without producing any output pulses (no saltation has occurred). Data examination cannot differentiate between a faulty sensor (no output) and no saltation (no output). Therefore, the KE output is integrated with a constantly running background signal. Every measurement period will record a count from this signal, even when no saltation has occurred. This is an indication that the sensor is working. Be aware that the frequency of the background pulse train can vary with temperature. Removing the background from the data is not exact because of this variation.

13. Soil moisture

Instrument: Campbell CS615 Water Content Reflectometer

Accuracy: +-2% when calibrated to the soil

Soil Temperature: Campbell model 107

Measurement range: -35°C to +50°C

Accuracy:
+-0.4°C -24° to +48°C
+-0.9°C -38° to +53°C

Accessibility FOIA Privacy Policies and Notices

U.S. Department of the Interior | U.S. Geological Survey
URL: http://gec.cr.usgs.gov/info/sw/clim-met/anatomy/index_nojava.html
Page Contact Information: GECSC Web Team
Page Last Modified: Fri 16-Apr-2010 13:08:36 MDT