Conductivity Tester

thingiverse

This container houses a 9V conductivity tester for the Don't Judge a Powder event at middle and high school Science Olympiad competitions. To participate, follow the circuit-building instructions available at http://scioly.org/wiki/index.php/Can't_Judge_A_Powder (copy and paste into browser). Use a 5mm LED for optimal fit. Secure connections with shrink wrap. Print box and lid in PLA to prevent cracking common in ABS prints. Assemble by inserting the LED through the hole, folding resistor and excess wire next to the battery, then adding the battery and wire. Seal the lid with tape if desired. Demonstrate the LED lighting in a glass of salt water versus filtered water.