Where can I get calibration solutions for an ORP sensor?

Vernier does not sell calibrating solutions for the ORP Sensor.

ORP reference solutions can be purchased from Hach Company. The order code for a bottle of 500 mL of 200 mV reference solution is 25M2A1001-115. The order code for a bottle of 500 mL of 600 mV reference solution is 25M2A1002-115.

Cole Parmer also carries ORP standard solution, order code: EW-05730-55.