HP-480TP, Panel-Mount Type pH Meter with Time-Sharing Proportional Control HP-480TP, HORIBA

The HP-480TP is a panel-mount industrial pH meter from HORIBA's 48/96 Series, combining full pH measurement functionality with an integrated time-division proportional control function. While the HP-480PL drives pulse-type dosing pumps directly, the HP-480TP controls solenoid valves, motor-driven pumps, and other devices that respond to relay on/off timing — modulating the duty cycle of the relay output within a fixed cycle time in proportion to the pH deviation from setpoint. The F-zone self-extending cycle time feature automatically lengthens the off-time of the duty when the measured pH enters a configurable range near the setpoint, providing smooth and precise control without overshooting. A maximum control volume setting further constrains reagent addition to prevent excessive dosing regardless of deviation magnitude. The HP-480TP fits the standard 48 × 96 mm DIN cutout and carries an IP65 panel face rating, sharing the same platform as the HP-480 with full 3 A relay contacts and CE marking.

Key Features HP-480TP

• Time-division proportional control: duty cycle of relay output modulated within cycle time (5–300 s) proportional to pH deviation; proportional band 0.00–4.00 pH; control output shift 0–50%.
• F-zone self-extending cycle time: when pH deviation enters a set range (1–100% of proportional band), the off-time automatically extends in proportion to deviation — providing smooth fine control near setpoint (disabled when shift function is active).
• Maximum control volume setting: 50–100% — limits reagent dosing regardless of deviation magnitude for process safety.
• ON/OFF control also available: upper/lower limit setting 0.00–14.00 pH; control width 0.00–4.00 pH (±0.00–±2.00 pH).
• pH measurement range 0–14, resolution 0.01 pH; temperature display 0–100 °C, 1 °C resolution (selectable).
• Isolated 4–20 mA DC transmission output; max. load resistance 900 Ω; free output range setting; repeatability and linearity ±0.05 pH / ±0.08 mA.
• Two relay contact outputs (SPDT 1c, 240 V AC / 30 V DC, 3 A): selectable upper/lower limit alarm, ON/OFF control, or maintenance mode.
• Two-point automatic calibration with automatic electrode validation; standard solutions pH 2/4/7/9/10; manual calibration available.
• Automatic temperature compensation 0–100 °C; supports NTC thermistors (350 Ω, 500 Ω, 6.8 kΩ, 10 kΩ at 25 °C) and Pt 1 kΩ; compensation can be disabled.
• Panel face IP65 (IEC60529 / JIS C0920); rear case IP20; ABS panel case; PBT terminals; Class II device IEC61010-1, Pollution Level 2.
• CE marked: EMC EN61326-1, Low Voltage EN61010-1, RoHS EN50581; FCC Part 15.

Applications

The HP-480TP is suited to pH monitoring and time-division proportional dosing control in industrial wastewater neutralization, chemical process pH adjustment, water treatment, and any application where relay-controlled devices (solenoid valves, motor pumps) are used for reagent addition and smooth proportional control near setpoint is required.

Installation and Safety Notes

Install into a standard 48 × 96 mm panel cutout. Power: 100–240 V AC, 50/60 Hz, 10 VA max. Panel face IP65; rear case IP20; terminals IP00 — protect the rear of the panel from moisture. Ultrasonic cleaners can be retrofitted without additional sequence control; for other cleaner types, customer-side sequence control is required. Operating temperature −5 to 45 °C; storage −25 to 65 °C; humidity 20–85% RH non-condensing.

Technical Specifications