russell betsuie environmental team supervisor gila river indian community department of...
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METEOROLOGICAL INSTRUMENTATION
Russell Betsuie Environmental Team Supervisor
Gila River Indian Community Department of Environmental Quality
METEOROLOGICAL INSTRUMENTATION
Gila River Indian Community Akimel O’odham (Pima) & Pee Posh (Maricopa) Located in Central Arizona, adjacent to Phoenix in
Maricopa & Pinal counties Established in 1859 by Executive Order 374,000 acres Population 15,500 people (on reservation)
+ 1, Keith’s baby daughter
METEOROLOGICAL INSTRUMENTATION
Meteorological Sensors Overview Wind speed Wind Direction Ambient temperature Relative humidity Barometric pressure Precipitation gauge
Brief overview Solar radiation Fuel moisture / Fuel temperature
Meteorological Tower Data Logger Documentation
Other information
METEOROLOGICAL INSTRUMENTATION
Wind Speed Sensor Propeller
Lightweight material Magnetically induced AC sine
wave output voltage Met Card
Frequency directly proportional to wind speed
Translator output is an analog voltage
Voltage applied to Data Logger Voltage In Card
METEOROLOGICAL INSTRUMENTATION
Wind Speed Sensor Cup assembly
Chopper wheel directly coupled to speed sensor which interrupts light path of optic link
Pulse frequency proportional to wind speed
Met Card
Translator output is an analog voltage
Voltage applied to data logger Voltage In Card
METEOROLOGICAL INSTRUMENTATION
Met One 010C Wind Speed Sensor Cover remove showing the
light chopper disk that produces the pulse frequency
Detector light assembly Electronic board
METEOROLOGICAL INSTRUMENTATION
Sine wave
Time
+
+
-
Hz (Hertz) is cycles per second
Use sensor unit specs for range
Wind Speed Sensor Frequencies
Pulsed frequency
METEOROLOGICAL INSTRUMENTATION
Voltage Signal Voltage Signal
1 Volt
999.3 Hz =100 MPH
Full Scale
If 1.0 volt = 100 Mile per hour then 0.5 volts = 50.0 MPH
0.5 Volt 552.2 Hz =50 MPH
Change is proportional
Basic Signal Concept
METEOROLOGICAL INSTRUMENTATION
Wind direction Sensor Lightweight vane material
Wind vane directly coupled to potentiometer
Potentiometer produce an analog output voltage
Voltage is proportional to vane angle (wind direction)
Voltage is applied to translator or data logger
Voltage In Card
METEOROLOGICAL INSTRUMENTATION
Wind direction Sensor Lightweight material
Airfoil shape Polyurethane Directly coupled to potentiometer Potentiometer produce an analog
output voltage Voltage proportional to vane angle
(wind direction) Voltage is applied to translator or
data logger Voltage In Card
METEOROLOGICAL INSTRUMENTATION
Voltage Degrees Voltage Degrees
1 Volt 360 Degrees
Full Scale
If 1.0 volt = 360 degrees then 0.5 volts = 180 Degrees
0.5 Volts 180 Deg.
Change is proportional
Basic Analog Concept
METEOROLOGICAL INSTRUMENTATION
Ultra Sonic Wind speed and direction
sensor combined Solid state Analog and Digital output No moving parts
Less maintenance No calibration required
METEOROLOGICAL INSTRUMENTATION
RM Young Vane Alignment Rod
Notch and box will always face true south with rod pointing to true north
Met One Cross-arm
Notch on direction sensor face south with cross arm pointing south / true north
METEOROLOGICAL INSTRUMENTATION
Compass will show magnetic north Set wind direction sensor to true north Each area has declination to use for correction to true
north Eastern part of U.S. declination is positive Western part of U.S. declination is negative
Web site www.ngdc.noaa.gov/seg/geomag/jsp/struts/calcDeclination
METEOROLOGICAL INSTRUMENTATION
Ambient Temperature Sensor High impedance thermistors or thermocouple
Cold temperature will increase sensor resistance Hot Temperature will decrease sensor resistance
Relative Humidity Sensor Measure water vapor contents of atmosphere
Works based on capacitive change Integrated Sensor unit
Advantage 2 sensors in one sensor (cost)
Disadvantage If temperature or relative humidity component is damaged.
Sensor must be replace sacrificing other sensor data
METEOROLOGICAL INSTRUMENTATION
2 types of Radiation Shields 1. Multi-plate Radiation Shield
White aluminum housing with disk plates
Protect sensors from rain and from direct sun rays
Allows air flow through plates to sensor located in center of shield
METEOROLOGICAL INSTRUMENTATION
2. Fan Aspirated Radiation Shield White coating on aluminum and white material housing Protect sensors from rain and from direct sun rays Fan produce continuous ambient air flow through shield and
sensor Prevents convective heat transfer to sensor Requires more cleaning of housing and replacement of fan
METEOROLOGICAL INSTRUMENTATION
Fuel moisture /fuel temperature sensor Basically a temperature and humidity sensor
Used for applications such as fire management Can help determine fire danger levels Used for determining fuel moisture & fuel
temperature of area. Mounted over fuel bed Typical fuels may be forest material: timber,
brushes & also trash
METEOROLOGICAL INSTRUMENTATION
Barometric pressure sensors Outside & Inside Sensors Detect atmospheric pressure Typically a solid-state pressure
transducer Internal electronic circuitry Analog output voltage
METEOROLOGICAL INSTRUMENTATION
Precipitation gauge Measures amount of rain fall Tipping bucket located below funnel Rain droplets collects in tipping
bucket Tipping action activates switch Switch closure sends signal to
translator box or data logger Important to level bucket, some
buckets have a internal bubble level
METEOROLOGICAL INSTRUMENTATION
Solar radiation sensor Solar Pyranometer
Detects amount of solar radiation from sun (sunlight)
Complements ozone data Complements fuel stick data
Operation Detector element: black & white Different rates of absorption Temperature differential Be aware of obstruction that may
effect data Shade from trees or buildings Night light from street lights
METEOROLOGICAL INSTRUMENTATION
Tower 10 x the distance of the height of obstruction (tree drip line, buildings) May not be ideal location due to:
Security Access Power Accessible
Reference: EPA Quality Assurance Handbook for Pollution Measurement Systems: Volume IV Meteorological Measurements
METEOROLOGICAL INSTRUMENTATION
Three Type of Met Towers 10 meter height (30 feet) Grounding kit Lowering clearance free of electrical lines Set hinge base correctly for lowering Concrete base or attach to structure and/or guy
wiring. Secure kids from climbing tower
1. Free Standing Tower Popular Needs clearance for lowering down Pre-plan for location of base tower
Courtesy: Aluma Tower Company Inc.
METEOROLOGICAL INSTRUMENTATION
2. Telescoping Tower No clearance for lowering
Tower stay in vertical position Top sections lowers into lower
section Hand or Electrical Winch
Parts for winch
Courtesy: Aluma Tower Company
METEOROLOGICAL INSTRUMENTATION
3. Tri-pod Tower Quick setup Guy wiring and secure footing Mobile
Gila River has a 10 meter tripod on roof of school library. Couldn’t secure footing on roof.
Courtesy: NovaLynx
METEOROLOGICAL INSTRUMENTATION
Data Loggers ESC
AC source, use in temperature control environment
Voltage Input Card Met Card
Tipping bucket, Sensor power source Campbell
DC source, use in outside ambient temperatures
Good for solar panels Retrieve data
Download data on laptop computer w/ RS-232 cable. Phone line w/ modem, Wireless, Satellite
METEOROLOGICAL INSTRUMENTATION
Sine wave 0 – 1 Volt etc. Pulse wave Resistance Voltage
0 – 1 Volt etc.
METEOROLOGICAL INSTRUMENTATION
Calibration equipment Vane Torque Gauge
Checks for wear on wind direction sensor bearing
Propeller Torque Disc Checks for wear on speed
sensor bearings Also used for Cup assay
sensors
METEOROLOGICAL INSTRUMENTATION
Calibration equipment Anemometer Drive
Wind-speed calibrator (RPM) Used for propeller and cup assay
sensor Annual calibration traceable to
NIST (National institute of Standard and Technology)
Vane Angle Stand Set points of degree angles Airfoil vane requires another
angle bench
METEOROLOGICAL INSTRUMENTATION
Calibration /verification of Sensors (manufacturer recommends annual or 6 months) Wind-speed sensor
7-point checks Wind-direction sensor
5-point checks
METEOROLOGICAL INSTRUMENTATION
Temperature Sensor Wet Bath 3 point check
Ambient Temperature Hot water Temperature Cold water TemperatureBe aware combination RH/Temp sensor can not be submerge in water
Relative Humidity Sensor Micro-Bath /Dry Cal Salt solutions
Chamber (very expensive)
METEOROLOGICAL INSTRUMENTATION
Precipitation gauge Verification equipment
Measured container or burette with Stand and nozzle squeeze container. Distill water (tap water causes residue)
In Clean rain bucket and screen(s) several times a year
Dirt, Leaves & Insects
METEOROLOGICAL INSTRUMENTATION
Barometric Pressure Sensor Digital Pressure device
1 point ambient pressure reading
Precipitation Rain Bucket Check level of bucket Measured amount of distill water
Graduated cylinder Burette w/ stand & nozzle squeezable bottle
Solar Radiation Sensor Clean sensor of debris Cover and Uncover sensor
METEOROLOGICAL INSTRUMENTATION
For cold climates sensor have internal heaters Maintenance
Clean sensors: direction vane, speed propeller or 3 cups assembly and temperature shield housing
Replace bearings and worn parts Lubricate rubber rings
Tighten connectors to sensors to prevent moisture damage
Check for crack lines Check guy wires and tighten bolts Tighten connectors to cross-arm shields and sensors
METEOROLOGICAL INSTRUMENTATION
Documentation Site log book Personal log book Site check list Calibration & audit forms Repair forms Purchase-order forms Ship for certification and/or repairs Shipping receipts Disposition forms etc…
METEOROLOGICAL INSTRUMENTATION
Recommendation Have some experience in Excel, Word, carpentry, electronics
and electricity Vendors to calibrate equipment and/or repair Purchase equipment similar to surrounding agencies
and tribal air programs For troubleshooting tips Audits
Items to have: Basis set of tools Digital multi-meter & 16 -14 gauge wiring Computer Conversion software Ty-wrap to secure cables Tap in monitor or sampler to collect certain data Solder
Pictures courtesy of: ESC, Met One, RMYoung, Cambell, Climatronics and SRMPIC.
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