... with back light 3.Temperature compensation 4. Anjun ph indicator controller with High QualityApplicationIndustrial waste water,pure water, circulating water,food ... : 4.00~20.00mA4.Operation: -10~+60degree;0~95% relative humidity, no condensing5.Storage: -20~+70°C;0~95% relative ... humidity, no condensing6.Relay: 2 relays; SPDT contactor, 3A 110/220VAC, ...