HI 21

Industrial Grade pH Digital Controllers Wall Mounted with Matching Pin

The HI 21 controllers are simple to operate, microprocessor-based pH process controllers packed with features. With HI 21 quick one, two or three point calibration at pH 4.01, 7.01 and 10.01 comes standard and you can choose from ON/OFF, proportional and PID control to save on chemicals. These instruments have a differential input, extending electrode life by eliminating ground loop current through the reference.

Password protection prevents unauthorized modifications in settings or calibration. The Fail Safe Alarm System protects the HI 21 against the pitfalls of process control, like power interruption or line failure.
Wiring the controllers is simple with extractable terminal modules. A host of self-testing features and user-friendly functions make HI 21 a great value.

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. Some HI 21 models are equipped with a bi-directional RS485 port, which allows remote control of the instrument from a PC.

Specifications
Range pH 0.00 to 14.00 pH
Temperature -9.9 to 120°C
Resolution pH 0.01 pH
Temperature 0.1°C
Accuracy @ 20°C pH ±0.02 pH
Temperature ±0.5°C
Input Impedance  1012 Ohm
pH Calibration  automatic, one, two or three point, at pH 4.01, 7.01, 10.01
Temperature
Compensation  automatic (with Pt100 probe) or manual from -9.9 to 120°C
Analog Output  0 to 1 mA, 0 to 20 mA, 4 to 20 mA; 0 to 5 VDC, 1 to 5 VDC, 0 to 10 VDC
Digital Output  RS485
Relays 1 and 2  electromechanical relay SPDT contact outputs, 5A-250 VAC, 5A – 30 VDC (resistive load) (HI 211YZ and HI 212YZ), fuse protected: 5A, 250V fast fuse
Alarm Relay  electromechanical relay SPDT contact output, 5A – 250 VAC, 5A – 30 VDC (resistive load) fuse protected: 5A, 250V, 250V fast fuse
Power Supply Input  ±5V (for amplified electrodes)
Power Supply  115 VAC ±10% or 230 VAC ±10%; 50/60 Hz
Power Consumption  15 VA
Over Current Protection  400 mA, 250V, fast fuse
Environment  0 to 50°C (32 to 122°F); RH max. 85% non-condensing
Protection  IP 54
Dimensions  221 x 181 x 86 mm (8.7 x 7.1 x 3.4’’)
Weight  1.4 kg (3.1 lb.)

Accessories
Solutions
HI 7004L
4.01 pH Buffer Solution
1 x 500 mL bottle
HI 7007L
7.01 pH Buffer Solution
1 x 500 mL bottle
HI 7010L
10.01 pH Buffer Solution
1 x 500 mL bottle
Accessories
HI 8427
pH and mV Precision Simulator
HI 931001
pH and mV Precision Simulator