Setting up and reading your Crystal Rain gauge
LOCATION
For accurate measurement, keep your rain gauge away from buildings, trees or other objects. The Bureau of Meteorology recommends a minimum distance of twice the height of the nearest object, and preferably four times the height. So, for instance, the gauge should be at least 10 metres away from a 5 metre high building and 30 metres away from a 15 metre high tree. To minimise the influence of wind on readings, keep the gauge as low as possible, while being safe from accidental damage and accessible for reading. Bureau of Meteorology rain gauges have the top of the collection funnel 300 mm above ground level. Keep surrounding grass and other foliage low.
For more details, visit the Bureau of Meteorology’s website at www.bom.gov.au.
Mounting and Assembly
The Crystal Rain Gauge stainless steel mounting bracket should be fixed to a secure support using the four stainless steel screws supplied. A fence post or similar is ideal. Make sure the bracket is vertical so the collection opening is level. With the bracket mounted, slide in the outer glass cylinder and rotate it so the measurements are visible through the left window. Assemble the collection funnel and inner cylinder as follows:
1. Check the silicone o-ring is in the groove around the collection funnel and the segmented foam rubber gasket is in place in the funnel spout.
2. Carefully insert the lugs on the inner cylinder in the slots on the funnel, push against the foam gasket and rotate anti-clockwise to secure them. The inner cylinder will now hang from the funnel with the gasket securing it.
3. Carefully lower the funnel and inner cylinder assembly into the outer cylinder and align its graduations so they’re visible from the front of the rain gauge.
The video below shows how to mount the Crystal Rain Gauge on a wooden fence post.
How to read
The Crystal Rain Gauge is designed to be readable from up to three metres away. The inner measuring cylinder measures up to 23mm rainfall.
Once the inner cylinder is full, it will overflow into the outer cylinder to measure up to 200mm of rainfall. Read approximate rainfall directly from the outer cylinder’s markings. For more accurate measurement, empty into the inner cylinder and add up the total. Record the day’s rainfall on the supplied rain chart.
Emptying the gauge
Lift the funnel and inner cylinder straight up. Holding the cylinder and funnel together, empty the cylinder and replace in the outer cylinder immediately.
If rain has overflowed into the outer cylinder, place the inner cylinder down on its side while removing the outer cylinder.
If the contents are frozen, you’ll need to thaw them by putting the cylinder(s) into warm water. While borosilicate glass can tolerate large changes in temperature it shouldn’t be exposed to direct flame.
Handling and care
The Crystal Rain Gauge is made from strong borosilicate glass. While it’s extremely durable and built to withstand extreme heat and cold, strong winds, sunlight and other environmental hazards, its glass cylinders are breakable.
So take care when removing the collection funnel and inner cylinder. Lift them straight up and disassemble and reassemble with care.
Do not stand the inner cylinder up if you’ve taken it out. It will break if you knock it over onto a rock!
If you should have an accident with any part, spares are available at a reasonable price. We want your Crystal Rain Gauge to last forever!
Cleaning
The glass parts of the gauge can be cleaned with normal dishwashing detergents and the supplied brush. Do not use any abrasives.
Keep the stainless steel bracket clean to avoid any corrosion spots, particularly if you’re near the coast.
When to measure
Bureau of Meteorology daily rainfall figures are normally measured at 9:00am each day. Of course for your own use, you can measure at any convenient time.