ORP standard solutions allow you to test the precision of ORP electrodes. For example, by immersing the electrode in HI 7020 solution, you should read within the 200 to 275 mV range (@20°C/68°F).
If the reading is outside the indicated interval, clean and condition your ORP electrode in HANNA® pretreatment solution. Use HI 7092 for oxidizing or HI 7091 for reducing pretreatment.
HI7042S Refilling Solution for Galvanic Probe, 30ml
HI937521-01 Calcium - Reagents - 50 Tests
HI98309 UPW - Ultra Pure Water Tester - Conductivity (up to 1.999 µS/cm)
HI710006 Power Adapter, 230 Vac to 12 VDC, European Plug
HI5001 - 1.00 pH@25°C - TQ - 500ml 



