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Home > Products > Insertion Ultrasonic Flowmeter > ST502 Insertion Ultrasonic Flowmeter with ±0.5% Accuracy, IP65 Enclosure, and RS485 Communication

ST502 Insertion Ultrasonic Flowmeter with ±0.5% Accuracy, IP65 Enclosure, and RS485 Communication

Product Details

Place of Origin: Shenzhen

Brand Name: Flo-Instru

Certification: CE; ISO9001

Model Number: ST502

Payment & Shipping Terms

Minimum Order Quantity: 1

Packaging Details: Conventional Packaging

Delivery Time: 3-5 working days

Payment Terms: T/T

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Highlight:
Repeatability:
0.15%
Output:
4-20mA, OCT Pulse Output, Relay Output, RS-232 / RS-485, RTD Temp. Input
Transducers Temperature:
-40℉ ~ +176℉ (-40℃~+80℃)
Velocity Range:
0.03 ~±40ft/s (0.01~±12m/s)
Power Supply:
24V DC
Pipe Size:
DN25-DN5000
Repeatability:
0.15%
Output:
4-20mA, OCT Pulse Output, Relay Output, RS-232 / RS-485, RTD Temp. Input
Transducers Temperature:
-40℉ ~ +176℉ (-40℃~+80℃)
Velocity Range:
0.03 ~±40ft/s (0.01~±12m/s)
Power Supply:
24V DC
Pipe Size:
DN25-DN5000
ST502 Insertion Ultrasonic Flowmeter with ±0.5% Accuracy, IP65 Enclosure, and RS485 Communication
ST502 Insertion Ultrasonic Flowmeter
Product Overview

The ST502 Insertion-Type Ultrasonic Flow Meter utilizes advanced digital signal processing technology to achieve ±0.5% high-accuracy flow measurement across a wide range of pipe sizes and clean liquid applications. Designed with a robust industrial-grade insertion probe, the ST502 provides strong ultrasonic coupling directly within the flow stream, ensuring excellent signal strength, long-term stability, and dependable performance.

A clear, intuitive user interface and menu system allow for easy configuration and operation. Unlike clamp-on models, the insertion design positions the ultrasonic transducers directly inside the pipe, enabling stronger signal penetration and enhanced stability—particularly beneficial for large-diameter pipelines, complex process conditions, or applications requiring highly reliable and repeatable measurements.

Engineered for versatility, the ST502 is ideal for water distribution systems, cooling loops, industrial process liquids, energy monitoring, and HVAC applications. Its combination of high accuracy, stable performance, and durable construction makes it a dependable solution for long-term flow monitoring and critical measurement tasks.

Key Benefits
  • Measures the actual flow and total consumption of various liquids
  • CNC machined process with magnetic open cover technology (no screws required)
  • Adaptive signal processing algorithms optimize performance in challenging flow conditions
  • Clear LCD display interface with alarm function for easy operation and debugging
  • Transit-time ultrasonic technology enables bidirectional flow measurement
  • Built-in 2G SD card for historical flow data analysis and system optimization
  • Built-in keypad and simple menu system for fast configuration
  • Aluminum alloy construction with full-sealed iron-absorbing side-opening technology
Measurement Principle

The Transit-Time (TVT) Ultrasonic Flow Meter is a highly reliable flow measurement technology widely used for clean liquids. Unlike clamp-on designs, the insertion-type meter places the ultrasonic transducers directly into the pipe wall so they make contact with the fluid. This ensures strong ultrasonic transmission, excellent signal quality, and stable long-term performance, especially on large or thick-walled pipes.

In an insertion-type TVT flow meter, two ultrasonic transducers are inserted into the pipe wall. One transducer transmits a pulse downstream (T_down) with the direction of the fluid, while the other transmits upstream (T_up) against the flow. Because the flowing liquid accelerates the downstream signal and slows the upstream signal, the time difference (Δt=T_up - T_down) is proportional to the flow velocity.

Technical Specifications
Performance Specifications
Velocity Range 0.03 ~ ±40ft/s (0.01 ~ ±12m/s)
Accuracy ±0.5%
Pipe Size 1"~200" (25mm~5000mm)
Repeatability 0.15% of measured value
Linearity ±1.0%
Compatible Fluids Water, Sea water, Oil, Alcohol, and more
Pipe Materials PVC, stainless steel, carbon steel, copper, and more
Function Specifications
Communication & Outputs ModBus RS485, 4~20mA analog output (max load 750Ω), 0~9999Hz pulse output (OCT), relay output (max 1Hz)
Flow Units Cubic Meters (m³), Liters (l), USA Gallons (gal)
Time Units /Day/Hour, /Min, /Sec
SD Card Storage Max 2GB, storage time interval: 1~86400s
Power Supply 24V DC/1A max
Keypad 16 touch keys
Display 20×2 lattice alphanumeric, back lit LCD
Temperature Range Transmitter: -40℉~140℉ (-40℃~60℃)
Transducer: -40℉~176℉ (-40℃~80℃)
Humidity Up to 99% RH, non-condensing
Physical Specifications
Transmitter Die-cast aluminum, IP65, CNC machined
Transducer Encapsulated design, protection grade IP68
Transducer Cable Standard cable length: 33ft (10m)
Weight Transmitter: 1kg
Product Dimensions
Transmitter Dimensions
ST502 Ultrasonic Flowmeter transmitter dimensional drawing
Transducer Dimensions
ST502 Ultrasonic Flowmeter transducer dimensional drawing
Product Display
ST502 Ultrasonic Flowmeter product display showing front panel and interface
Communication & Output Functions

The ST502 Fixed Ultrasonic Flow Meter is equipped with multiple communication and output options to ensure seamless integration into various industrial control systems. These outputs enable real-time data acquisition, remote monitoring, and control of flow-related processes.

ST502 communication and output functions diagram ST502 wiring and connection interface
Output Type Function Application Examples
RS485 (Modbus) Digital communication Remote monitoring, SCADA, system integration
4-20mA Analog input/output PLC input, process feedback, DCS systems
OCT Pulse Flow totalization output Batch controllers, energy meters, flow loggers
Relay Alarm/control output Trigger alarms, control valves/pumps, flow safety protection
Wiring Diagram & Installation Methods
ST502 Ultrasonic Flowmeter wiring diagram and installation methods