Storage set for pH electrodes

A 200 turn wire coil on a bobbin that has a base with three terminals that accommodate banana plug contacts for measuring current or voltage. Can be mounted on a Helmholtz base.

A 400 turn wire coil on one end of a wand that has two terminals at the other end to accommodate banana plug contacts, permitting easy connection of an electric circuit.

When plugged into a detector coil, the LED flashes red or green as the detector coil passes through the magnet to indicate which direction the current flows through the detector coil.