Hanna Instruments HI7021L ORP Test Solution at 240 mV, 500mL Bottle
ORP solution for platinum and gold electrodes. Reads 240 mV at 25 degree C/77 degree F. ORP standard solutions allow you to test the precision of ORP electrodes. If the reading is outside the indicated interval, clean and condition your ORP electrode in Hanna pretreatment solution. Size: 500ml. Pack of 1.