

Flow Measurement Instruments
- Flow Meter Calibration Services
- Rheotherm Flow Instruments – Model 210R
- Rheotherm Flow Instruments – Model 210
- Thermal Low Flow Liquid Meters
- Thermal Low Flow Gas Meters
- Thermal Duct Flow Meters for Air & Gas
- MaxExtractor Extraction Monitor
- Multi-Variable Process Meter
- Bidirectional Flow Meters
- RheoVac ® Multisensor Flow Monitors
- Flow Switches
- Instruments for Hazardous Locations
- Custom Process Measurement
- Electronics Options
- Low Flow Controller
Bidirectional Flow Meters
Bidirectional flow meters, also known as two-way flow meters, are specialized instruments designed to measure flow rates in both forward and reverse directions within a single pipeline. At Bionetics Corporation, we offer Rheotherm flow meters, an advanced solution for measuring bidirectional flow in liquids and gases.
Measuring unidirectional flow is common and can be achieved with the help of advanced flow technologies. However, accurately measuring bidirectional flow remains a challenge, as many conventional meters fail to deliver precise readings for reverse flow. This can lead to process interruptions, inaccurate measurements, and financial losses. The Rheotherm Model 213 Bidirectional flow meter addresses this challenge by providing highly-accurate measurements for both liquids and gases. Our Rheotherm flow meters eliminate measurement discrepancies, ensuring seamless operation and enhanced productivity for process industries.
Bidirectional Flow Measurement
Bidirectional flow measurement plays a crucial role in various industrial applications, including the monitoring of dielectric fluid flow in underground electric cables. This process is essential for ensuring the efficient dissipation of heat generated by high-voltage power lines. In such applications, a bidirectional flow meter is used to track both the forward and reverse movement of dielectric fluids, allowing for precise monitoring and control of flow direction. These fluids, injected from utility pumping and circulating plants, help in maintaining the operational integrity and longevity of underground power transmission systems.
Bidirectional flow measurement is critical in detecting anomalies such as leaks, pressure drops, or inefficiencies in the fluid circulation process. Advanced bidirectional meters not only measure flow rates but also analyze real-time data to optimize energy consumption and system performance. By integrating modern bidirectional measurement technology, utilities can enhance reliability, improve safety, and ensure uninterrupted power transmission while reducing maintenance costs.
What Can We Measure?
The Bionetics Rheotherm Model 213 is a highly precise instrument designed for applications that require accurate measurement of extremely low flow rates, down to 0.2 cc/min. This two-way flow meter is ideal for industries such as pharmaceuticals, biotechnology, and chemical processing, where precise flow measurement is critical. Unlike traditional meters, Rheotherm flow meters operate without moving parts, eliminating the need for regular maintenance while ensuring long-term calibration accuracy. These meters offer exceptional versatility, as they can be constructed from various wetted materials, making them chemically compatible with a broad range of fluids, including corrosive and high-purity substances.
The Bidirectional meter efficiently measures flow in both directions, making it an excellent solution for applications involving reversible fluid movement. This capability is particularly beneficial in systems where liquid or gas needs to be monitored in dynamic flow conditions, such as fuel recirculation, cooling loops, and laboratory research. With its ability to provide stable and reliable readings even at ultra-low flow rates, the two-way flow meter supports critical process control and optimization.
For more details or to discuss your specific flow measurement requirements, Contact Us using the form on this page or email us at sales-flow@bionetics.com.
How Are They Installed?
Rheotherm flow meters feature in-line flow sensors that are commonly installed using standard tube fittings. Optional configurations include flanges, sanitary fittings, and other connection types. In some models, the electronics are built directly into the sensor for a compact solution. Other models offer a separate electronics enclosure that can be located up to 200 feet away from the sensor, providing flexibility for various installation scenarios.
How Do They Work?
The Rheotherm Model 213 Bidirectional flow meter is a highly precise in-line flow meter designed to measure both the rate and direction of fluid movement without any mechanical components. This makes it an ideal sanitary flow meter, ensuring contamination-free operation. It utilizes a straight-through flow tube equipped with a series of resistance temperature detectors (RTDs) attached externally. Two RTDs monitor the fluid temperature, while a third RTD measures the temperature of a low-power heater that is cooled by the flowing liquid. The temperature differential between the heated and unheated RTDs generates the primary flow signal, enabling precise flow measurement. Since the sensors do not come into direct contact with the fluid, the system remains highly durable, with no risk of wear, sticking, or breakage, making it suitable for various industrial and sanitary applications.
What sets this bidirectional meter apart is its ability to determine flow direction with exceptional accuracy. When fluid moves from left to right, RTD1 records the incoming temperature, while RTD2, positioned downstream of the heater, registers a slightly elevated temperature due to the heat transfer. Conversely, if the fluid flows from right to left, RTD2 captures the initial temperature, while RTD1, now downstream, becomes the hotter sensor. By comparing the temperature readings of the unheated RTDs, the system accurately identifies flow direction. This method ensures reliable, maintenance-free performance for applications requiring bidirectional flow measurement. The Rheotherm Model 213 is ideal for industries requiring precision, such as pharmaceuticals, food processing, and chemical manufacturing.
How Do I Get One?
Enhance your process efficiency with Rheotherm’ s bidirectional meters, engineered to accurately measure flow in both directions. These meters are ideal for applications such as monitoring dielectric fluid in underground cables, ensuring precise flow data without process interruptions. With no moving parts, they offer maintenance-free operation and can detect flow rates.
Our experts are ready to discuss your specific needs and configure an instrument tailored to your application. Visit our Contact Us page for telephone, fax, and email information. Let us help you optimize your processes with industry-leading technology.
- No moving parts
- Exclusive inline TU sensor
- Advanced signal processing electronics
- Field adjustable
- Maintenance-free
- Easy installation
- Choice of wetted materials
- Long-term reliability
Standard | Options | |
Temperature | Process: 0 – 140°F (-18 – 60°C) Environment: 0 – 120°F (-18 – 50°C) | -20 – 350°F (-30 – 175°C) |
Pressure | 0 – 1,000 PSI | Up to 30,000 PSI |
Line Sizes (flow range dependent) | 1/16”; 1/8”; 3/16”; 1/4”; 3/8”; 1/2”: 5/8”; 3/4”; 1” | Other sizes via fittings/adapters |
Process Connection | Plain tube stubs suitable for compression fittings | – MNPT: – Tri-Clover (Sanitary); – SS Flange (1/2″ – 2″); Most other fittings available |
Wetted Material | 316 SS | – Hastelloy C-276®; – Monel®; – Alloy 20; – Titanium; – Tantalum; – Inconel |
Display | 2 X16 backlit LCD with selectable display of: – Mass/volume flow rate – temperature – total accumulated flow | |
Standard | Options | |
Enclosure | Sensor: PVC Integrated Electronics: NEMA 4X Cast Aluminum Remote Electronics: NEMA 4 | Sensor: Stainless steel Remote electronics: – Stainless steel – NEMA 7 Explosion-proof |
Hazardous Environment | Integrated electronics FM-Approved for: – Class I, Div. 1, Groups B,C,D – Class I, Zone 1, IIB+H2 (US) – Class II, Div. 1, Groups E, F, G – Class III, Div. 1 | |
Outputs | 4 – 20 mA (flow rate) or Serial Burst with Flow Rate, Totalizer, and Fluid Temperature | – 0 – 10 or 0 – 5 VDC; – HART (4-20 mA) ; |
Input Power | 24 VDC (9 – 36 VDC) (200 mA – blind unit; 300 mA w/display option) | 110/230 VAC ±10V |
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