Contents

Rain Collector (# 7852 & 7852M)
- Note: Model number 7852 is factory-calibrated to take rain measurements in 0.01 inches. The metric version, 7852M, comes factory-calibrated to take measurements in 0.2 mm.
Components
- The rain collector includes the following components. Please make sure you have all listed components before continuing.
- Tools and Materials Needed
- Rain Collector Internal Components
Prepare the Rain Collector
- 1. Turn the rain collector upside down and remove the cone from the base by rotating the base until the latches on the cone line up with the latch openings in the base then lifting the base away from the cone.
- 2. Carefully cut and remove the plastic tie which holds the tipping spoons in place during shipping.
Test the Rain Collector
- 1. Open the transmitter shelter on the ISS. Remove the foam insert and feed the rain collector cable up through the opening. Plug the cable to the appropriate connector in the sensor interface (See illustration on page 5.)
- 2. Press the RAINDAY button on your console to display rainfall.
- 3. While watching the display on your console to see if it changes, slowly tip the bucket until it drops to the opposite side. Each tip indicates 0.01" or 0.2 mm of rain. (It may take up to a minute for the first tip to register at the console.) If t...
Install the Rain Collector
- Note: Climbing on your roof may be hazardous. If you are uneasy about installing your unit please have a qualified professional complete the installation. Davis specifically disclaims any liability for injury or loss resulting from the installation o...
  - Choosing a Location for the Rain Collector
  - Installing the Rain Collector
  - Tip: Manuals are available online at www.davisnet.com in the Weather Support section.
    - 1. If you have not already done so, separate the cone from the base and disconnect the rain collector cable from the sensor interface in the transmitter shelter.
    - 2. Place the base on the mounting surface and mark the location of the four holes (the base has eight to choose from) you will use to secure the base.
    - 3. Make pilot holes using a 3/32" (2 mm) drill bit. You should make the pilot holes about 1/2" (12 mm) deep.
    - 4. Fasten the base to the mounting surface using the #8 x 3/4 screws provided.
    - 5. Open the transmitter shelter on the ISS. Remove the foam insert and feed the rain collector cable up through the opening. Plug the cable to the appropriate connector. Replace the foam and close the shelter.
    - 6. To be certain the rain collector is functioning properly after installation, retest the unit. See Test the Rain Collector on page 3.
    - 7. To use the bird spikes, insert one spike in each socket around the rim of the cone. The sockets are tapered: push firmly or tap lightly with a hammer for a more secure fit.
    - 8. Place the cone back onto the base by putting the latches on the cone into the latch openings in the base and rotating the cone clockwise until the latches lock into place. As you reattach the cone, make sure to run the cable to the cable slo...
    - 9. Place the debris screen, pointed end up, into the cone. The screen prevents large bits of debris from blocking the funnel hole. If bird nesting is a problem, you can place a spike in the hole on top of the debris screen. Note that using a bird spi...
- Note: If you choose not to install bird spikes now, keep the packet of spikes for possible future use.
  - 10. To prevent fraying or cutting of the cable where it is exposed to weather, it is important that you secure it so it doesnt whip about in the wind.
- Use cable clips or weather resistant cable ties to secure the cable. Place clips or ties approximately every 3 to 5 feet (1 to 1.6 m). Do not use metal staples or a staple gun to secure cables. Metal staplesespecially when installed with a staple ...
  - Extending Cable Runs
Adjusting the Rain Collector
- Note: Modify both adjustment screws by the same amount.
- Note: Avoid comparison to rainfall readings obtained from television, radio, newspapers, or neighbors readings. Such readings are not an accurate measurement of the weather conditions in your specific location. The rain collector is carefully test...
Maintaining the Rain Collector
- 1. Disconnect the rain collector cable from the sensor interface in the transmitter shelter.
- 2. Separate the cone from the base.
- 3. Use a soft damp cloth to clean pollen, dirt, and other debris from the cone, cone screens, and bucket.
- 4. Use a pipe cleaner to clear the funnel hole in the cone and the drain screens in the base. When all parts are clean, rinse with clear water.
- 5. Reattach the cone and replace the debris screen.
- 6. Reconnect the rain collector cable to the sensor interface.
Troubleshooting Guide
- Contacting Davis Technical Support
Specifications
- Sensor Type Tipping bucket with magnetic reed switch
- Output Contact closure
- Attached Cable Length 40 (12 m)
- Cable Type 4-conductor, 26 AWG
- Connector Modular connector (RJ-11)
- Recommended Max.Cable Length 900 (270 m)
- Housing Material UV-stabilized ABS plastic
  - Dimensions
  - Rain Collector and base 8.75" diameter x 9.5" high (22.2 cm diameter x 24 cm high)
  - Collection Area 33.2 in2 (214 cm2)
- Range
  - Daily Rainfall 0.00 to 99.99 (0.0 mm to 999.8 mm)
  - Total Rainfall 0.00 to 199.99 (0.0 mm to 6553 mm)
- Accuracy For rain rates up to 2"/hr (50 mm/hr): 4% of total or +0.01 (0.2mm) (0.01" = one tip of the bucket), whichever is greater. For rain rates from 2"/hr (50 mm/hr) to 4"/hr (100 mm/hr): 5% of total or +0.01 (0.2mm) (0.01" = one tip of ...
  - Update Interval 20-24 seconds
- Input/Output Connections
  - Red Switch terminal
  - Green & Yellow Switch terminal

Davis 7852 Instruction Manual

Pages 8

Year 0

Language(s)

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Davis 7852 Rain Collector Specification

The Davis 7852 Rain Collector is a precision instrument designed for accurate measurement and reporting of rainfall. Engineered with advanced aerodynamic design, it minimizes rain-induced measurement errors, providing precise data even in extreme weather conditions. The rain collector features a robust UV-resistant, weather-proof housing that ensures long-lasting durability in outdoor environments. Its tipping bucket mechanism is constructed from high-grade materials, enabling it to measure rainfall in increments as fine as 0.01 inches (0.2 mm) with exceptional accuracy.

The collector is compatible with Davis weather stations and can be integrated seamlessly into existing systems for real-time data transmission and analysis. Equipped with a debris screen, the rain collector minimizes potential obstructions or clogging, ensuring consistent performance. Maintenance is simplified with an easily removable cover, allowing for straightforward cleaning and inspection. The Davis 7852 is designed to withstand temperatures ranging from -40°F to 140°F (-40°C to 60°C), making it suitable for diverse climates.

Installation options are versatile, allowing the collector to be mounted on flat surfaces or poles, ensuring optimal placement for accurate readings. The device also includes a built-in leveling feature to facilitate proper setup and enhance measurement precision. With its combination of durability, accuracy, and ease of use, the Davis 7852 Rain Collector is ideal for both amateur weather enthusiasts and professional meteorologists seeking reliable rainfall data collection.

Davis 7852 Rain Collector F.A.Q.

How do I install the Davis 7852 Rain Collector?

To install the Davis 7852 Rain Collector, mount it on a level surface using the included hardware. Ensure it is positioned in an open area away from obstructions. Connect the collector to your weather station using the appropriate cable.

What should I do if the rain collector is not recording rainfall accurately?

First, check for any debris blocking the funnel. Ensure the collector is level and securely mounted. Verify the connection to the weather station and inspect the tipping bucket for any obstructions or damage.

How often should I clean the Davis 7852 Rain Collector?

It is recommended to clean the rain collector at least once a month, or more frequently if you live in an area with heavy pollen, dust, or bird activity.

Can the Davis 7852 Rain Collector be used in freezing temperatures?

The rain collector is not designed for use in freezing temperatures as ice can damage the tipping mechanism. Consider using a heated rain gauge if you require measurements in freezing conditions.

How do I calibrate the Davis 7852 Rain Collector?

To calibrate, use a graduated cylinder to pour a known amount of water into the collector and verify the output matches the expected rainfall. Adjust the calibration screws if necessary. Consult the manual for detailed calibration procedures.

What maintenance is required for the Davis 7852 Rain Collector?

Regularly check for and remove any debris from the funnel and tipping bucket. Ensure the collector remains level and clean the internal components as needed. Inspect for any signs of wear or damage.

How can I prevent birds from interfering with the rain collector?

Install bird spikes or a bird guard around the collector to deter birds. Regular cleaning and maintenance can also help prevent bird-related issues.

What should I do if the rain collector is leaking?

Inspect the collector for cracks or damage. Check the sealing gasket and ensure all connections are tight. Replace any damaged parts to prevent leaks.

Is it possible to connect the Davis 7852 Rain Collector to a computer for data logging?

Yes, you can connect the rain collector to a compatible weather station that supports computer connectivity. Use the appropriate software to log and analyze the data on your computer.

How do I troubleshoot connectivity issues with the Davis 7852 Rain Collector?

Check the connection cables and ensure they are securely attached. Restart both the rain collector and the weather station. Update the firmware if necessary and consult the product manual for further troubleshooting steps.