Contents

Standard Anemometer
- Installation Manual
- Components
- Hardware
  - Tools and Materials Needed
  - Note: Make sure the clips or ties you use to secure the anemometer cable have screw holes or other means for mounting the cable. Do not use metal staples to secure the cables.
- Testing the Anemometer
  - 1. Connect the anemometer cable to the appropriate connector on your junction box.
  - 2. Push the wind cups onto the smaller of the two stainless steel shafts at the end of the arm.
  - 3. Spin the wind cups gently. You havent secured them yet, and if you spin them too hard you may knock them off.
  - 4. Check the display on your weather station to make sure you are getting a wind speed reading.
  - 5. Grasp the upper, larger of the two stainless steel shafts at the end of the arm with your fingers and twist the shaft about 1/2 turn.
  - 6. Check the display to make sure the wind direction reading on your display changes.
  - Note: The wind direction readings will not change as rapidly as you turn the shaft. The station uses a low pass filter to smooth out the constant small shifts in wind direction and keep the direction display from jumping about in gusty winds.
    - 7. Disconnect the cables when you are finished testing the anemometer.
- Assembling the Anemometer
  - 1. Push the wind cups onto the smaller of the two stainless steel shafts.
  - 2. Slide the wind cups as far up the shaft as possible.
  - 3. Use the allen wrench provided to tighten the set screw on the side of the wind cups.
  - 4. Spin the wind cups. If they do not spin freely, loosen the set screw, lower the cups slightly, then retighten the set screw.
  - 5. Repeat Step 4 until the wind cups spin freely.
- Choosing the Best Anemometer Location
  - Note: If you live in an area subject to frequent thunderstorms, installing a lightning rod nearby can reduce the risk of damage.
    - Orient the Wind Vane
- Installing the Anemometer
  - Installing on a Sensor Mounting Arm
  - Check the Anemometer Base Orientation
    - 1. Insert the anemometer arm into the base.
    - 2. Attempt to push the #4-40 x 1 1/4" pan head screw through the holes in the arm and the base.
    - 3. If the screw does not slide easily through the holes, rotate the base 180 to line up the opposite holes, then try again.
  - Installing the Base on a Wooden Post or Surface
    - 1. Hold the anemometer base against the wood surface and use a pencil to mark the location of the four holes on the base.
    - 2. Use a drill with a 3/16" (5-mm) drill bit to make pilot holes in these locations.
    - 3. Drive the lag screws through the holes in the anemometer base and into the wood.
  - Installing on Antenna Mast or Metal Pipe
    - 1. Hold the anemometer base against the pipe and insert the two U-bolts through the back of the base so that the U-bolts wrap around the pipe.
    - 2. Place a 1/4" washer and a 1/4-20 hex nut over each end of the U-bolts and use a wrench to tighten the hex nuts.
    - 1. Use two stainless steel hose clamps to attach the mounting base to masts or pipes larger than 1 1/4" diameter, large enough to fit around the mast or pipe and the anemometer base.
    - 2. Hold the anemometer base against the pipe and fasten the hose clamps over the anemometer base and around the metal mast or pipe.
  - Attaching Arm to Base
    - 1. Insert the anemometer arm into the anemometer base.
    - 2. Insert the pan head screw into one of the holes in the base and slide it through the arm.
    - 3. Secure the pan head screw using the flat washer, lock washer, and hex nut as shown.
  - Installing the wind vane
    - 1. Slide the wind vane down onto the shaft as far as it will go. (Because of the shape of the shaft, the vane will only go on one way.)
    - 2. Use the allen wrench provided to tighten the set screw on the side of the wind vane.
    - 3. Test your assembly by pointing the wind vane in any direction and (using the compass or map as a guide) making sure the console displays the correct wind direction.
    - 4. Because of the low pass filter used by the station, allow the wind direction reading approximately 5 seconds to stabilize after you turn the vane.
    - 5. Spin the wind cups to make sure you get a wind speed reading. Readjust the cups if necessary.
    - 6. Secure the cable to the metal mast or pipe with electrical tape. Secure the rest of the cable according to the directions below.
  - Securing the Cable
  - Securing cable
  - Note: Do not use metal staples to secure cables. Metal staples can cut the cables.
- Maintenance
  - CAUTION: DO NOT attempt to lubricate the wind cup shaft and bearings or the wind vane shaft. Natural or synthetic lubricants will inhibit the normal operation of the anemometer.
- Troubleshooting
  - Wind speed reads 0 all the time or intermittently or wind direction reading is dashed out
  - Wind speed reading seems too high or too low
- Contacting Davis Instruments Technical Support
- Specifications
  - Wind Direction
  - Accuracy: 3
    - Wind Speed
  - Range: 0 to 200 mph., 1 to 322 kph, 1 to 173 knots,0.5 to 89 m/s
  - Accuracy: 2 mph (3 kph, 2k ts,1 m/s) or 5%, whichever is greater

Davis 7911 Installation Manual

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Davis 7911 Anemometer Specification

The Davis 7911 Anemometer is a precision instrument designed for accurate wind speed and direction measurement, essential for meteorological and environmental monitoring. The device features a robust design, built to withstand harsh weather conditions, ensuring durability and reliable performance over time. Constructed with high-quality materials, the anemometer includes a corrosion-resistant, UV-stabilized thermoplastic that protects its sensitive components from environmental damage.

The wind speed measurement range of the Davis 7911 spans from 1 to 200 mph (1.6 to 322 km/h), with a resolution of 1 mph (1.6 km/h) and an accuracy of ±2 mph (±3.2 km/h) or ±5%, whichever is greater. It utilizes a cup-anemometer design, which allows for responsive and precise wind speed detection. The wind direction is measured using a wind vane, providing full 360-degree detection with a resolution of 16 points (22.5 degrees) and an accuracy of ±7 degrees.

This anemometer is equipped with a 40-foot (12-meter) cable, facilitating flexible installation options for optimal data collection. The Davis 7911 is compatible with the Davis Vantage Pro2 weather stations, enabling seamless integration into existing systems for comprehensive weather monitoring and data analysis. The anemometer's simple design allows for straightforward installation and maintenance, requiring minimal technical expertise.

Overall, the Davis 7911 Anemometer is engineered to deliver precise and consistent wind data, making it an ideal choice for applications ranging from agricultural and industrial monitoring to academic research and personal weather stations. Its reliable performance, coupled with ease of use, establishes it as a trusted tool for professionals who require accurate wind analysis.

Davis 7911 Anemometer F.A.Q.

How do I properly install the Davis 7911 Anemometer on a mast?

Ensure the anemometer is mounted at least 10 feet above any obstructions. Attach the unit securely to the mast using the provided mounting hardware, and ensure the wind cups and vane can rotate freely.

What should I do if the anemometer is not recording wind speed accurately?

Check for obstructions or debris in the wind cups or vane. Ensure the unit is mounted level and the cable connections are secure. Perform a manual spin test to verify the cups spin freely.

How can I calibrate the Davis 7911 Anemometer for precise readings?

The anemometer is factory-calibrated. If recalibration is needed, compare readings with a known reference and adjust using the compatible monitoring console, if available.

What maintenance does the Davis 7911 Anemometer require?

Regularly inspect for debris, clean the wind cups and vane with mild soap and water, and check for any signs of wear or damage. Lubricate moving parts annually with a light machine oil.

How do I replace the bearings in the anemometer?

Disassemble the anemometer by removing the wind cups and vane. Carefully remove the old bearings and install new ones, ensuring they are seated properly before reassembling the unit.

What should I do if the anemometer's wind vane is not pointing in the correct direction?

Check for physical obstructions and ensure the vane is not damaged. Re-align the vane with true north using a compass and adjust the mounting as necessary.

Can the Davis 7911 Anemometer be used in extreme weather conditions?

Yes, the anemometer is designed to withstand extreme weather conditions, including high winds, rain, and snow. Ensure it is securely mounted to prevent damage.

How do I connect the Davis 7911 Anemometer to a weather station console?

Use the provided cable to connect the anemometer to the input jack on the compatible weather station console. Follow the console's manual for configuration settings.

What are the common signs of wear and tear on the Davis 7911 Anemometer?

Look for cracks in the wind cups or vane, rust on the mounting hardware, and any looseness in the moving parts that might affect performance.

How can I test the functionality of the Davis 7911 Anemometer after installation?

Perform a manual spin test by gently spinning the wind cups and observing the corresponding readings on the connected console. Verify that the wind direction changes as you move the wind vane.