Electroscope

Two thin leaves of copper foil in a glass jar. They spread apart when they touch something charged. It's the cheapest electrical instrument, and it's deliberately a rough one.

Crafting

A Copper Foil above a Glass block.

F
G

Using it

• Right-click any electrical block (cable, cell, generator, magnet) to get a voltage reading on your action bar, like "Electroscope: 1.0 V".
• Carry it anywhere in your inventory and Jade's tooltip on electrical blocks shows volts as well as Live/Dead.

What it can't do

It only shows voltage, and only roughly: readings come in steps of 0.5 V, so a cell's 1.1 V reads as 1.0 V and small differences along a cable won't show up. It can tell you a line is live and roughly how strongly. It can't tell you how much current is flowing. For that you need a Galvanometer.

Tips

• Touch it to an Electrostatic Generator while someone turns the handle, and you'll see the leaves jump and fall again.
• Compare the reading at a Galvanic Cell with the reading at the far end of a long cable. If they differ, the cable is costing you power.