Flow Measurement Instruments
- Low Flow Liquid Meters
- Low Flow Gas Meters
- Duct Flow Meters for Air & Gas
- Low Flow Controller
- MaxExtractor Extraction Monitor
- Multi-Variable Process Meter
- Bidirectional Flow Meters
- RheoVac ® Multisensor Flow Monitors
- Flow Switches
- Custom Process Measurement
- Instruments for Hazardous Locations
- Electronics Options
Low Flow Liquid Meters
Low flow liquid meters are specialized flow measurement devices that measure small liquid volumes and low flow rates. These low flow liquid flow meters are essential for monitoring and controlling liquid flow in processes demanding high precision. The Bionetics Corporation provides Rheotherm flow meters, including Rheotherm Model 210 flow meters, which are an excellent—often the only—choice for reliable liquid flow measurement at low flow rates.
Our low flow liquid flow meters are ideal for flow rates from 1 gallon/year to a few gallons per minute (GPM). These flow meters are maintenance-free, and deliver repeatable and reliable results. We also provide low-volume flow meters for hazardous environments, including intrinsically safe and NEMA 7 explosion-proof models. Being a market leader in flow monitoring devices since 1978, we ensure the highest standards of quality and reliability. All our low flow liquid meters are ISO 9001:2015 certified.
Exploring the Diverse Applications of Rheotherm Liquid Flow Meters
Our Rheotherm Model 210 flow meters are designed to measure the continuous flow of a wide range of low and high-viscosity homogenous fluids and slurries. Its unique inline sensor design ensures an unobstructed flow path. Offered in various materials, our low-volume flow meters are compatible with most fluids. Our inline liquid flow sensors can measure everything from liquified gases to thick oils, pastes, corrosive chemicals, light hydrocarbons, water-based fluids and water. Rheotherm low-volume liquid flow meters can be used to measure the following fluids:
- Liquid chlorine
- Antifoam
- Aluminum sulfate
- Polymer
- Biocide
- Magnesium oxide
- Magnesium sulfate
- Magnesium sulfonate
- Sodium hypochlorite (NaOCl)
- Hydrofluorosilicic acid (HFSA)
- Ferric chloride (FeCl3)
- Sodium hydroxide (NaOH)
In addition to the above, our inline flow meters have been successfully used to measure a wide range of chemicals listed here.
Industries Served
The versatility of our low volume liquid flow meters makes them an ideal monitoring tool across the following industries and more.
- Chemical/Petrochemical
- Aerospace
- Natural Gas
- Oil & Gas Production
- Wastewater Treatment
- Pulp & Paper
- Nuclear
For more information on industries and applications of inline water flow sensors, please visit our industries served page.
Installation Process Overview of Low Flow Liquid Meters
The installation process of Rheotherm high-accuracy liquid flow meters is straightforward as discussed below.
- Rheotherm flow meters feature inline flow sensors installed using standard tube fittings. They are optionally offered with flanges, sanitary fittings, and other configurations to meet your application requirements.
- The flow meters can be installed in any orientation, except vertical with a downward flow direction.
- Some models have integrated electronics, whereas others have a separate electronics enclosure that can be installed up to 200 feet from the sensor. This option is beneficial in restricted spaces.
- Choose FM-approved intrinsically safe sensors and/or FM/cFM-approved explosion-proof integral units for hazardous environments. Please visit our page on Electronics Options for various models of Rheotherm low flow liquid meters.
How Rheotherm Flow Meters Accurately Measure Fluid Flow?
The Rheotherm Model 210 liquid flow meters operate on the principle of thermal flow measurement. It determines the flow rate by analyzing the thermal properties of the fluid passing through the device’s body. The meter utilizes a straight-through or looped flow tube, and two resistance temperature detectors (RTDs) mounted on the tube’s exterior. Generally, a heated and unheated RTD is used for the process. The temperature differential between these RTDs provides the primary flow signal. The differential is lower at high flow rates because the heat is removed effectively through the flow. The differential is higher at low flow rates due to reduced heat removal. The continuous and consistent flow of homogenous liquid ensures accurate flow measurement without gauging the fluid pressure.
The unobstructed fluid path ensures that the fluid only contacts the fluid tube wall. Even the presence of solids in the fluid will not damage the sensor. In short, the unobstructed fluid path helps eliminate wear, tear, or breakage of mechanical parts. The Model 210 is available without a local display but has an optional 2 x 16 backlit LCD display that shows mass/volume flow rate, temperature (°C or °F), and total accumulated flow.
Flow data can be extracted in both digital and analog formats, allowing routing to the digital display or an off-site computer. Additionally, the Model 210 has a self-diagnostic feature that automatically detects system issues and generates fault codes for user review.
Eager to learn more about the method of operation of Rheotherm inline flow meters? Please visit our Rheotherm Method of Operations page.
How to Order Rheotherm’s Low Flow Liquid Flow Meter?
You can contact our flow application specialists using the form on this page to configure a Rheotherm flow meter tailored to your application, low flow meters liquid RFQ. You can also download and complete the Flow Application Data Sheet and email it to us at sales-flow@bionetics.com.
For any product related queries or assistance, please visit our Contact Us page for telephone, fax and email information.
Explore the key features of our low volume flow meters that enhance their performance, reliability, and ease of use across applications.
- No moving parts
- Exclusive inline TU sensor
- Typical calibration ranges: 10:1 and options up to 200: 1 turndown
- Durable sensors, unaffected by over-ranging
- Advanced signal processing electronics
- Field adjustable; easy onsite calibration adjustments
- Maintenance-free
- Easy installation
- Choice of wetted materials
- Long-term reliability
- Stores up to four calibration curves
- Extended temperature compensation
- Optional remote electronics configuration
- Hazardous environment options
We provide low flow liquid meters in the following specifications.
| 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 |
| Calibration Ranges | – 10:1 Turndown – 0.007 cc/min to 20 GPM | – Up to 200:1 turndown; – Four calibration channels available (for multiple flow ranges or fluids using the same sensor) |
| Calibration Accuracy | ± 1% of reading typical | |
| Response Time | 1 sec. ; 3 – 5 sec. typ. (63% of range) | Time constant/delay option |
| Repeatability | ± 0.5% of reading | |
| Standard | Options | |
| Line Sizes (flow range dependent) | Capillary; 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 Remote electronics: Same as above except addition of Group A using ISB | |
| Outputs | 4 – 20 mA (flow rate) or Serial Burst with Flow Rate, Totalizer, and Fluid Temperature | – 0 – 10 or 0 – 5 VDC; – Pulse (5 VDC open collector); – HART (4-20 mA) ; – SPDT relay; – 4 to 20 mA temp |
| Input Power | 24 VDC ±4V (200 mA – blind unit; 300 mA w/display option) | 110/230 VAC ±10V |
The table below outlines the flow capacities of inline sensors used for liquid measurement.
Inline Sensor Flow Capacities for Liquids
| TUBE SIZE | ||||||||||
| FLOW RATE LIMITS | C | 1/16 | 1/8 | 3/16 | 1/4 | 3/8 | 1/2 | 5/8* | 3/4* | 1* |
| Extended Maximum | 2 | 60 | 500 | 0.4 | 1 | 2.5 | 4.6 | 8 | 10 | 20 |
| Normal Maximum | 1 | 30 | 250 | 0.25 | 0.5 | 1 | 2 | 3.5 | 4.5 | 8 |
| Normal Minimum | 0.03 | 0.8 | 6 | 0.008 | 0.01 | 0.03 | 0.05 | 0.2 | 0.3 | 0.5 |
| Extended Minimum | 0.007 | 0.05 | 3 | 0.002 | 0.006 | 0.01 | 0.02 | 0.07 | 0.1 | 0.2 |
| cc/min | GPM | |||||||||
*Limited applications. Consult Factory
This section offers you access to all essential documentation for our Rheotherm low flow liquid flow meters.
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