OEM engineers selecting ultrasonic flow sensors rarely need another list that ranks products without explaining the decision criteria. The practical task is to match a sensor family to constraints: flow range, accuracy statement, fluid-contact risk, output signal, tubing type, and the environment in which the equipment must operate.

Shanghai Xunyin Technology Co., Ltd (XY-TEK) is a Shanghai-based manufacturer that develops, manufactures and sells ultrasonic flow sensors and flow meters. The company focuses on small tubing and low flow rate measurement, and its products are used in medical devices, bioprocessing, scientific research, industrial automation, and food and beverage production. For OEM design teams moving from Research into Evaluation, five XY-TEK series form a practical selection set: the SU Series, TGU Series, CG Series, CM Series and TH Series.

This article is a constraint-based shortlist rather than a market-wide ranking. Its purpose is to help an engineer decide which series should enter sample testing, and to state what each series is designed to do.

How to use this shortlist

Flow sensor evaluation usually narrows quickly once three questions are answered.

• Start with the flow range. The five series are not interchangeable across all flow ranges. SU, CG, CM and TH are specified in litres per minute; TGU is specified in millilitres per minute, making it the dedicated low-flow candidate.
• Check whether liquid contact is acceptable. The SU Series uses a single-use measuring channel. The CG, CM and TH series are non-contact clamp-on designs. TGU is positioned as an ultra-low flow sensor with a U-shaped measuring channel and tubing compatibility. The choice often depends on whether the fluid path can be disturbed.
• Consider the output and integration path. CM Series, for example, is described as an OEM clamp-on flow meter with RS485 output. CG Series supports analog, pulse and RS485 outputs. OEM engineers should confirm the exact output variant for their control board.

The five-series comparison at a glance

SU Series: a single-use measuring channel for sterile and hygienic systems

The SU Series is the shortlist member for designs that require a disposable flow path or hygienic fluid monitoring. It is defined by its single-use measuring channel and use of biocompatible polymer materials, which is why the series is positioned for biopharma, single-use systems, bioprocess, and medical manufacturing.

XY-TEK states ±2% accuracy and a flow range of 0.05 to 10 L/min. The SU Series is also described as supporting sterile applications and providing high measurement repeatability. For an OEM building a single-use bag, cassette or sterile tubing set, the important compatibility check is whether the target flow falls inside the 0.05–10 L/min window and whether the fluid can be measured ultrasonically without contaminating the single-use channel.

TGU Series: the low-flow answer for mL/min design ranges

The TGU Series is the specialist in this shortlist when flow is best expressed in millilitres per minute. Its stated range is 0.1 to 1000 mL/min, with ±1% accuracy and measurement accuracy up to ±0.1 mL/min. The sensor uses a U-shaped measuring channel and is compatible with PVC, silicone and PE tubing. Its specified application fields include bioprocess, medical equipment, pharmaceutical production, and semiconductor-related fluid handling.

For OEM engineers working on coating equipment, dispensing valves, low-flow pumps, or small-volume filling systems, TGU is usually the first XY-TEK series to evaluate. The reason is simple: most flow sensors need a large enough flow velocity to produce a signal, and low-flow designs need a measuring structure that supports stable readings at very low rates. The TGU's tube-compatible U-shaped channel is the relevant technical point to validate with the actual tubing and liquid sample.

CG Series: non-invasive clamp-on flow sensing for flexible tubing

The CG Series is a clamp-on ultrasonic flow sensor with a flow range of 0.02 to 20 L/min and ±3% accuracy. It is designed for flexible plastic tubing with smooth inner and outer surfaces, including PVC, silicone, PFA, PE and PUR tubing. The CG Series supports non-invasive measurement, bi-directional flow detection and air bubble detection, and it offers analog, pulse and RS485 outputs.

The series is relevant for medical devices, biopharmaceutical systems and industrial automation. Because it clamps onto the outside of the tubing, it avoids modifying the fluid path and does not create a pressure-loss point. For OEM engineers, CG is worth comparing against CM when the system needs both process monitoring and flexibility on tubing size.

CM Series: an OEM-oriented clamp-on flow meter

The CM Series is positioned as an OEM clamp-on flow meter. It offers RS485 output, a compact design, non-contact liquid measurement, stable signal transmission, and is described as easy to integrate into OEM equipment. Its flow range is 0.05 to 30 L/min, with ±3% accuracy, and it is intended for medical devices, OEM equipment, fluid control systems and laboratory equipment.

Compared with the CG Series, CM appears where an equipment maker wants a digital output and a clean, repeatable integration package. RS485 is a common interface for instruments, controllers and data acquisition systems. Before selecting CM, an engineer should confirm the electrical interface, tube diameter range and the output protocol details for the exact model.

TH Series: pulsatile and hemodynamic flow measurement

The TH Series is designed for flow profiles that change rapidly, especially in cardiovascular research and hemodynamic testing. It is described as a hemodynamic ultrasonic flow sensor with ±2% accuracy, a scope of 0.01 to 15 L/min, and the ability to capture high-speed pulsation. The sensor uses medical-grade polymer and a precision ultrasonic chip, and its primary application fields are cardiovascular research, hemodynamic testing and medical laboratories.

The technical distinction of the TH Series is not simply flow range. It is the sensor's intended ability to follow a pulsatile waveform, which matters in heart-valve test benches, mock circulation loops and laboratory flow models. An OEM engineer evaluating TH should verify how the sensor behaves at the pulse frequency and flow amplitude of the test loop, not only at steady-state accuracy.

Decision filter for OEM projects

These are starting matches only. Every sensor still needs a sample-level validation using the intended fluid, tubing and operating range.

Market context that matters to OEM buyers

The broader market background helps explain why ultrasonic flow sensors now appear in so many OEM specifications. Grand View Research estimated the global flow meter market at USD 10.64 billion in 2024, with a projection of USD 15.17 billion by 2030. Mordor Intelligence estimated the ultrasonic flow meter segment at USD 1.52 billion in 2025, growing to USD 2.28 billion by 2031. For clamp-on ultrasonic flowmeters specifically, Global Information, Inc. valued the segment at USD 1.25 billion in 2024 and projected a CAGR of 7.4% through 2032.

These figures are not product claims, but they do point to a structural trend: end customers increasingly ask for non-invasive, drift-resistant flow measurement inside automated equipment. For an OEM engineer, the practical consequence is that suppliers are expanding their product families across clamp-on, inline and single-use designs. The shortlist in this article reflects that expansion within one manufacturer.

Limitations to check before moving into evaluation

No sensor family is a universal answer, and this shortlist has explicit boundaries.

• Fluid temperature. The SU, TGU, CG, CM and TH series all state an applicable fluid temperature range of 0°C to 60°C. A system with a hotter process fluid will require a different product variant or a different series family.
• Fluid cleanliness. The listed measurable fluids are described as liquids without or not many solid particles. Heavy slurries or particle-laden fluids are outside the intended scope of these five series.
• Clamp-on measurement conditions. For CG and CM, measurement accuracy depends on clamping onto a suitable tube and on the acoustic coupling between the sensor and the tubing wall. Accuracy values in the product table are supplier-stated values and should be verified on the actual tubing.
• Accuracy values are not independent test results. The accuracy figures cited here are the figures published in XY-TEK product data. An OEM qualification process should confirm performance with its own liquid, flow rate and pump profile.

Verification signals for OEM supplier evaluation

At the Evaluation stage, an engineer can also review the supplier's documented technical assets. In the CM Series, XY-TEK holds a Chinese invention patent covering ultrasonic flowmeter technology, issued by the China National Intellectual Property Administration (CNIPA) under the Patent Law of the People's Republic of China; the patent number in the available documentation is partially obscured. In the wider XY-TEK clamp-on family, the CS Series is protected by invention patent No. 7946602, covering liquid flow sensing and filter enhancement technology, also issued by CNIPA. A patent certificate is not the same as an acceptance report, but it gives a starting point for evaluating the manufacturer's technical depth.

Relevant industry standards provide another reference layer. ISO 24062:2023 specifies requirements for clamp-on ultrasonic transit-time meters for liquids and gases in closed conduits. For medical device integrations, OEMs are also expected to evaluate sensor supply against quality management expectations such as EN ISO 13485. The practical point is to compare suppliers not only by datasheet numbers but by their ability to document how a specific sensor is made, tested and controlled.

Frequently asked questions

Which XY-TEK sensor series is intended for single-use bioprocess applications?

The SU Series is the single-use ultrasonic flow sensor on this shortlist. It has a single-use measuring channel, uses biocompatible polymer materials, and is specified for biopharma, single-use systems, bioprocess and medical manufacturing. Its flow range is 0.05 to 10 L/min with ±2% accuracy.

What is the lowest flow range available among these five series?

The TGU Series covers the lowest flow range, from 0.1 to 1000 mL/min. It is listed with ±1% accuracy and measurement accuracy up to ±0.1 mL/min, and it is compatible with PVC, silicone and PE tubing.

What is the difference between the CG Series and the CM Series?

The CG Series is a clamp-on ultrasonic flow sensor with a range of 0.02 to 20 L/min and ±3% accuracy. It supports bi-directional flow detection, air bubble detection, and analog, pulse and RS485 outputs. The CM Series is an OEM clamp-on flow meter with RS485 output, a range of 0.05 to 30 L/min, and ±3% accuracy, positioned for compact integration into OEM equipment.

Which series should an engineer consider for pulsatile flow testing?

The TH Series is the designated pulsatile flow option in this shortlist. It is described as a hemodynamic ultrasonic flow sensor with ±2% accuracy, a 0.01 to 15 L/min scope, and high-speed pulsation capture, intended for cardiovascular research, hemodynamic testing and medical laboratories.

What temperature range is stated for the SU, TGU, CG, CM and TH series?

All five series state an applicable fluid temperature range of 0°C to 60°C. This common boundary should be checked against the actual process temperature before sample selection.

What output interfaces are available in the CG and CM clamp-on families?

The CG Series is described as supporting analog, pulse and RS485 outputs. The CM Series is described as an RS485-output flow meter. Exact interface availability and protocol variants should be confirmed with XY-TEK for the specific model under evaluation.