The Seojin Instech ST-600 Series Float Type Level Transmitter, configuration model code ST-600-A-1-A-6-A-3-F, is 100% designed, engineered, and manufactured in South Korea by Seojin Instech Co., Ltd. Globally recognized as a benchmark continuous liquid level telemetry solution, the ST-600 series delivers high measurement repeatability, mechanical durability, and long-term operating stability across thermal power plants, municipal water treatment utilities, industrial steam boiler systems, and large-scale bulk fuel storage terminals.

The operating principle is governed by Archimedean liquid buoyancy coupled with non-contact magnetic actuation. Inside a heavy-duty stainless steel SUS304 stem, a linear ladder circuit consisting of precision reed switches and resistors is hermetically sealed and serially arranged at fixed intervals of 10 to 20 mm. A cylindrical float equipped with an internal permanent magnet travels smoothly along the stem corresponding to the rising or falling liquid level. The magnetic field emitted by the float closes the adjacent reed switches, sequentially altering the total circuit resistance proportional to the liquid height. The integrated electronic head converter instantaneously transforms this resistance variation into an industry-standard 4 ~ 20mA DC analog output signal (2-wire loop powered at 24VDC), delivering reliable, interference-immune level telemetry directly to plant PLCs, DCS controllers, or digital indicators.

The ST-600-A-1-A-6-A-3-F configuration is specifically engineered for deep vessels, featuring an extended measurement range up to 0 to 6 meters (code 6). All wetted components—including the guide stem, magnetic float, travel stoppers, and process flange—are fabricated from premium SUS304 stainless steel (code A), providing superior resistance against chemical corrosion, oxidation, and mechanical wear under working pressures up to 10 kg/cm² and temperatures up to 100 °C. The electrical terminal housing is cast from heavy-duty ADC12 aluminum alloy with an industrial protective finish certified to IP65 weatherproof standards (code A). Outfitted with a standardized JIS 10K 80A 6T FF flange (code 1) and a dedicated electrical conduit connection (code F), the ST-600 ensures robust sealing against environmental moisture, offering seamless field installation and virtually maintenance-free operational life.

• Manufacturer: Seojin Instech Co., Ltd.
• Origin: 100% Korea (South Korea)
• Product Series: Float Type Level Transmitter (ST-600 Series)
• Configuration Model Code: ST-600-A-1-A-6-A-3-F
• Measurement Principle: Magnetic float actuating a series of internal reed switches and precision resistors
• Measuring Part Length: 0 ~ 6 Meters (Code 6 - Extended maximum deep-tank measurement)
• Output Signal: 4 ~ 20 mA DC (2-Wire Loop Powered)
• Operating Power Supply: 15 ~ 32V DC (Standard 24V DC)
• Measurement Resolution: Approx. 10 mm ~ 20 mm
• Measurement Accuracy: ±10 mm
• Field Calibration: Integrated Zero and Span trimmers located on the internal converter board
• Wet Part Material (Stem, Float, Flange, Stopper): Stainless Steel SUS304 / 304SS (Code A)
• Magnetic Float Style & Dimension: Cylindrical SUS304 float Ø79 mm × 90 mm Height (or Ø75 mm option)
• Minimum Medium Specific Gravity: 0.85 g/cm³ and above
• Process Operating Temperature Range: -10 °C to +100 °C
• Maximum Vessel Operating Pressure: Up to 10 kg/cm² (~10 bar)
• Process Mounting Connection: JIS 10K 80A 6T FF Flange (Code 1)
• Electrical Enclosure: Weatherproof Housing (Code A), heavy-duty die-cast aluminum ADC12 with protective powder coating
• Enclosure Protection Rating: IP65 according to IEC 60529
• Conduit Cable Connection: Option F conduit connection (PF 1/2" or PF 3/4")
• Applicable Industries: Thermal power stations and steam boiler utilities (feedwater and condensate tanks), municipal water distribution and industrial wastewater plants, standby generator diesel storage tanks (DO/FO), centralized heavy-machinery lubrication systems, industrial cooling tower basins, mild chemical storage tanks, deep underground fire-water sumps, and marine shipboard liquid cisterns.