You will need an aluminum beverage can, scissors, water, ice and a thermometer to complete this method of measuring dew point. If you want to do this experiment on a larger scale, use a metal bucket instead. You might also benefit from having a pencil and paper to record your results. Cut off the top portion of the lid. For a clean cut, use a can opener. Be gentle and take your time or else you may have sharp aluminum protruding out. Check the weather forecast before starting the experiment. To accurately measure dew point, instead of frost point, the temperature should be above freezing. Aim for 60 °F (16 °C) weather for best results. You can still proceed with your experiment if the weather is colder or warmer.
++++++++++
One-sentence summary -- Gather the materials. Cut your aluminum can. Complete the experiment on a day when temperatures are above freezing.


Grip the last 1–2 feet (30–61 cm) of the 10/4 cable between the jaws of a wire stripper and pull them toward the end to cut off the coating. Clamp the stripper 1⁄2 inch (1.3 cm) from the ends of each wire from inside the cable and remove the insulation around them. Work on 1 wire at a time so you don’t accidentally damage them. Use a utility knife to cut through the coating on the 10/4 cable if you can’t remove it with your wire strippers. The safety panel on your circuit breaker box is the cover that hides all of the wires and breakers inside. Locate the screws around the edges of the circuit breaker box and rotate them counterclockwise to loosen them from place. Set the panel aside while you’re working so it’s out of the way. Never remove the safety panel cover while the power is still on. This could cause to get electrocuted. Inspect the sides or top of the circuit breaker box to look for a circular piece that has a precut edge around it, also known as the knockout. Position the end of a screwdriver in the middle of the circle, and tap on the screwdriver’s handle with a hammer to punch the knockout out from the side.  You can use a hole in the side of your circuit breaker box that already has wires running through it if there’s room for your cable. You may have to drill through the circuit breaker box if there aren’t any more knockouts you can use. Be sure to use a drill bit meant for metal. A cable clamp is a small cylindrical shape with metal bars on top to protect cables and hold them so they don’t slip. Get a cable clamp that matches the size of the knockout on your circuit breaker box, and slide the clamp through the hole. Screw the locking nut onto the threaded end of the clamp to hold it securely against the box. You can buy cable clamps from your local hardware store. Push the 4 wires from the 10/4 line between the bars on top of the cable clamp so they go inside the circuit breaker box. Pull the wires into the box completely so you have 1–2 feet (30–61 cm) of wire to work with. Once the wires are inside, tighten the screws on the top bars of the clamp so the wires don’t move around.  Don’t feed any part of the 10/4 cable that still has the outer coating since it won’t hold the wires as securely. You can always loosen the clamp if you need to pull more wire into the circuit breaker box if it wasn’t initially long enough. A double-pole breaker allows twice the power to run through it as a standard 15-amp single pole breaker, and takes up the same space as 2 single-pole breakers. Find a spot along the line of other breakers where the double-pole breaker will fit. Push in the top of the breaker into the metal clips inside the box so it snaps into place before pushing the bottom into place.  You can buy double-pole breakers from your local hardware store. Make sure you get a breaker that matches the circuit breaker box brand you have. Make sure the breaker is off before you install it. Different brands of breakers snap into place in various ways, so check the instructions before you install it so you don’t accidentally damage them. Once you have it in place, locate the 2 ports in the bottom of the breaker where you’ll connect the power. Take the ends of the black and red wires and feed one of them into each of the ports. Tighten the screws on the bottom of the breaker with a screwdriver to hold the wires in place. It doesn’t matter which ports the black and red wires go into since they’re both transferring power to the outlet. Look on the inside walls of the circuit breaker box to find a bar with multiple screws and wires attached to it, which is the grounding bar. Bend the ends of the green and white wires into hooks and wrap them around separate screws along the bar. Tighten the screws so the wires don’t move or shift around. Don’t wrap the wires around screws that already have other wires around them since you could short out the power or cause a current to travel to a different appliance. Hold the safety panel up to the circuit breaker box so you can find where the new breaker lines up with it. Place the end on your screwdriver over the slots where the breaker would go, and tap the end with a hammer to punch it out. Pull off the piece of the safety panel you punched out so the breaker fits easily. You don’t have to punch out any slots if the breaker already lines up with an existing hole in the panel. Hold the panel back up against your circuit breaker box and reattach the screws with a screwdriver. Make sure the safety panel sits tightly on the front of the box and that none of the wires are exposed. Once you finish, turn the main power back on the circuit breaker box so you can use your outlet.
++++++++++
One-sentence summary --
Strip the insulation from the 10/4 cable and the wires that will connect to the circuit breaker. Remove the safety panel from the front of the box. Take out the circular knockout on the side or top of the circuit breaker box. Put a cable clamp in the hole you just knocked out. Feed the wires from the cable through the clamp into the box. Install a 30-amp double-pole breaker on the circuit. Push the ends of the red and black wires in both ports of the breaker. Wrap the green and white wires around the screws on the grounding bar. Knock out the slots on the circuit breaker box’s safety cover that line up with the breaker. Screw the cover back on the circuit breaker box before turning it on.