The Holykell HPT604, part number 604BL16FGE5S10D2N2003, is a submersible hydrostatic level transmitter designed for continuous liquid-level measurement. It operates on 24 V DC, measures levels from 0 to 2.5 m, and provides a standard industrial 4–20 mA output for connection to PLCs, displays, controllers, and monitoring systems.

Product Description

Holykell HPT604 Submersible Level Sensor – 0–2.5 m – 4–20 mA – 24 V DC

The Holykell HPT604 is a hydrostatic submersible level sensor designed for accurate and reliable measurement of liquid levels in tanks, reservoirs, wells, basins, and industrial installations. When immersed in a liquid, the sensor converts the hydrostatic pressure generated by the liquid column into a proportional 4–20 mA analog signal.

With its calibrated measuring range of 0 to 2.5 metres, this model is especially suitable for low- and medium-depth liquid-level applications. Its 24 V DC supply allows straightforward integration into industrial control panels, automation systems, pump-control equipment, data-acquisition modules, and programmable logic controllers (PLCs).

The HPT604 series uses piezoresistive pressure-sensing technology and is designed for submerged level measurement in demanding environments. Depending on the exact version, the series features a robust metal housing and a vented measuring cable for reliable hydrostatic level measurement.

Technical Specifications

• Brand: Holykell
• Series / Model: HPT604
• Manufacturer Part Number: 604BL16FGE5S10D2N2003
• Serial Number: 23041130001
• Device Type: Submersible hydrostatic level transmitter
• Measuring Range: 0 to 2.5 m
• Measured Variable: Liquid level / liquid column height
• Output Signal: 4–20 mA
• Power Supply: 24 V DC
• Measurement Technology: Piezoresistive pressure sensor
• Installation: Direct immersion in the liquid
• System Compatibility PLC, level display, controller, SCADA system, data logger
• Red wire Vcc+ / positive power supply
• Green wire: Si+ / positive signal
• Yellow wire: Shield / cable screening

Main Application Water-level and compatible-liquid measurement

With a standard 4–20 mA output, the sensor can transmit measurements reliably over relatively long cable distances. In a typical configuration, 4 mA represents 0 m and 20 mA represents 2.5 m of liquid level.

Areas of Application

The Holykell HPT604 is suitable for installations requiring continuous, accurate, and automatable liquid-level monitoring, including:

• Water-storage tanks, reservoirs, and elevated water tanks.
• Boreholes, wells, and groundwater-level monitoring systems.
• Rainwater-harvesting tanks, underground cisterns, and retention basins.
• Pumping stations, booster systems, and automatic pump-control installations.
• Water-treatment facilities, technical tanks, and industrial process reservoirs.
• Agricultural irrigation tanks, farm water reservoirs, and livestock watering systems.
• Sewage-treatment applications, sump pits, and wastewater tanks, subject to liquid compatibility.
• Water-level management in buildings, hotels, hospitals, schools, factories, and public infrastructure.

For corrosive liquids, fuels, heavily contaminated water, or hazardous/explosive environments, verify the sensor’s material compatibility, cable material, diaphragm type, and applicable certifications before installation.

Project Examples

• Automatic overhead-tank control: Install the HPT604 at the bottom of a water tank, connect its 4–20 mA output to a PLC or programmable relay, and automatically start or stop the borehole pump according to configured water-level thresholds.
• Rainwater-tank monitoring: Connect the sensor to a 4–20 mA level indicator or an IoT monitoring system to display available water volume and activate an irrigation pump when the tank contains sufficient water.
• Borehole monitoring and dry-run protection: Use the transmitter to monitor water levels in a well or borehole, protect the pump from dry running, and send status information to a remote supervisory system.
• Industrial basin control: Integrate the sensor with a PLC to operate a drainage pump, solenoid valve, or high-level alarm whenever the liquid level reaches a predefined setpoint.
• Building water-reservoir automation: Automatically manage the filling of a water tank in a hotel, school, apartment building, or factory while displaying the actual water level in the electrical control panel.