The pH 500 series controllers have a 4 - 20 mA output with a zoom function to allow better resolution on any two points between 0 and 14 pH. The fullyprogrammable microprocessor comes complete with a 3 month back-up power supply to maintain all set points and parameters during power interruptions. Easy 1 or 2 point calibration using pH buffers 4.01, 7.01 or 10.01 ensure accuracy or reliability. An additional standard feature of the HA-504 is a differential circuit which eliminates ground loops from the process being monitored and significantly extends the life of the electrode.

Specfications

• Range: -2.00 to 16.00 pH; -2000 to 2000 mV; -30 to 130.0°C 
• Resolution: 0.01 pH; 1 mV; 0.1°C (above -10 °C); 1°C (below -10°C)
• Accuracy (@ 20°C/68°F): ±0.02 pH; ±2 mV; ±0.5°C (-9.9 to 130.0°C); ±1°C (-30 to -10°C)
• Input Impedance: 1012 Ohm 
• Isolated output; contact closed upon Hold mode 
• 1 or 2 independent outputs (configuring as 0-20 mA or 4-20 mA) 
• Dosing and Alarm Relay: electromechanical relay SPDT contact output; 5A - 250 Vac, 5A - 30 Vdc (resistive load) fuse protected: 5A, 250V “Quick Blow” fuse 
• Temperature Compensation: automatic or manual, -30 to 130°C 
• Temperature Probe: Pt100/Pt1000 sensor (with automatic recognition and damage test)
• Power Supply: 24 Vdc/ac, 115 Vac ±10%, 230 Vac ±10%, 100 Vac ±10%; 50/60 Hz 
• Environment: 0 to 50°C (32 to 122°F); RH max 85% non-condensing 
• Casing: IP54 (front panel) 
• Dimensions / Weight: panel cutout:140 x 140 mm, instrument: 144 x 144 x 170 mm / 1.6 kg (3.5 lb.)