The pH 500 series of controllers are simple to operate, microprocessor-based process meters packed with features. For more flexibility and better resolution for chart recorders, any two points between 0 and 14 pH can be chosen to correspond to the analog output spans. Push button password programming prevents tampering. The Fail Safe Alarm System protects the pH 500 against the pitfalls of process control, like power interruption or line failure. With pH 500 quick one, two or three point calibration at pH 4.01, 7.01 and 10.01 comes standard. The temperature can be manually or automatically compensated for. It is supplied complete with mounting brackets and instructions. Range: 0.00 to 14.00 pH; -9.9 to 120 degree C. Resolution: 0.01 pH; 0.1degree C. Accuracy at 20 degree C: + / -0.02 pH; + / -0.5 degree C. 1012 Ohm input impedance. automatic, one, two or three point, at pH 4.01, 7.01, 10.01 pH calibration. automatic or manual from -9.9 to 120 degree C temperature compensation. Analog, galvanically isolated: 0-1 mA, 0-20 mA and 4-20 mA, 0-5 VDC, 1-5 VDC and 0-10 VDC output. 2 contact outputs SPDT 5A-250 VAC, 5A-30 VDC ( resistive load) , fuse protected ( 2A, 250V fast fuse) set point relay. 1 contact output SPDT, 5A-250 VAC, 5A-30 VDC ( resistive load) , fuse protected ( 2A, 250V fast fuse) alarm relay. 115 VAC + / -10 percent, 50/ 60 Hz power supply. 15 VA power consumption. 400 mA 250V fast fuse over current protection. 4 MHz max oscillation frequency. 0 to 50 degree C ( 32 to 122 degree F) ; RH maximum 95 percent non-condensing environment. Measures 144mm length by 144mm width by 170mm height. 115V. Weight: 1.6 kilograms.