Snowfall is often just measured by its depth in inches (or centimeters). But there are other important factors to consider. The density, the temperature, and the crystal shape all greatly affect how the snow behaves when you try to work with it. So it might be useful if we also measured other properties of snow as well.
For instance, if you have to shovel snow, the thing that you are most concerned about is the weight of the snow. To measure this, I made a simple scale that can be read remotely. This lets you monitor the snowfall from the comfort of your warm house. It makes a great addition to any DIY home weather station.
Step 1: Materials
Kitchen Scale (preferably one that doesn't zero itself when turned on)
Four Long Wires
Small Plastic Bowl
Fine Toothed Saw or Rotary Cutting Tool
Hot Glue Gun
Step 2: Background: How a Digital Scale Works
A load cell is typically a metal bar with a sensor glued to the side of it. On older scales this sensor would be a simple strain gauge that changes its resistance as the bar is deformed. The circuit measures the change in resistance and converts that to a weight measurement. Newer scales often have multiple sensors with built-in circuitry. These sensors output serial data that is then processed by the external circuit.
Most digital scales have a tare button that resets the reading to zero. This is very useful for calibrating the scale. However, some scales automatically reset themselves every time that they turn on. This feature is very problematic for this design. This would require the scale to be constantly on in order to measure any new snowfall. If you have this kind of scale, I would recommend using an Arduino to monitor the output of the load cell instead of using the original monitoring circuit. This option is discussed more in step 11.
Step 3: Open the Housing of the Scale to See How All the Parts Are Laid Out
On this scale the load cell takes up half the housing and the monitoring circuit takes up the other half. The load cell is connected circuit board with a single 4-wire cable. The load cell and the circuit board are both attached to the housing with screws.
Step 4: Remove All the Parts From the Housing
Step 5: Cut the Housing into Two Sections
Once all the internal parts had been removed, I fit the two pieces of the housing back together and I marked a line between each section. Then I used a fine toothed saw to slowly cut through the whole housing.
Step 6: Connect the Load Cell to the Circuit Board With Extension Wires
You want the cable to be long enough to go from the location where the load cell will be placed to the location where you set up the monitoring circuit. I wanted to set up the monitoring circuit in my kitchen window and the sensor a few feet out in the yard. So I used about ten feet of wire to connect the two parts.
Step 7: Mount the Scale Parts Back into Each Section
Step 8: Seal the Cut Opening on Each Section
Step 9: Mount a Bowl to the Plate to Catch the Snow
Step 10: Set Up the Scale to Monitor Snowfall
Step 11: Alternative Setup: Monitor the Snowfall With an Arduino
Using an Arduino gives you quite a few options as to how you will monitor and process your snowfall data.