Low Flow Meters for Small Pipe Sizes
ALSONIC-MINI
SmartMeasurement’s ALSONIC-MINI is a best-in-class clamp-on transit-time ultrasonic low flow meter specifically designed to accurately measure ultra-low flow rates in small-diameter pipes.
Size Range: ½”-2″ (15-50 mm) line sizes
Temperature Range: 32~+122 °F ( -0 ~ +50˚C)
Accuracy: 2% of reading
Applications: Chemical, DI-water, corrosive fluids
Starting At: $500
SmartMeasurement’s ALSONIC-MINI is a clamp-on transit time ultrasonic flowmeter designed for small pipe sizes and ultra-low flow rates. The unique design of the ALSONIC-MINI allows it to be installed directly onto the pipeline without the use of coupling gel or the need to manually adjust transducer spacing. The plug and play installation method makes use of a magnetic circular clamp to achieve & maintain contact in between the transducers and the pipe wall. Total installation time is less than three minutes, significantly reducing the amount of time needed to install a traditional clamp-on meter.
ALSONIC MINI-2 for Small Pipe Sizes
For unique applications where traditional clamp-on meters would not ordinarily be feasible, see our ALSONIC MINI-2, a special-purpose clamp-on ultrasonic meter designed for small line sizes and ultra-low flow rates. It features:
- Clamp on installation for DN8~DN40 (0.25-1.5”) pipes. Best for extremely small pipe diameters.
- OLED display with two touch buttons, keypads for setup and diagnostics, adjustments, etc. Comprehensive adjustment done through MODBUS RTU
- Velocity range of 0.08-10 mps (16-1900 fpm)
- Compatible with more common industrial or utility piping – with flexibility across a range of small pipe sizes, especially if you’re working in the field or want one device for multiple systems.
Why Choose SmartMeasurement’s Low Flow Meters?
Precision at Low Flow Rates
Meters maintain ±2% accuracy even down to 0.1 m/s, ensuring reliable readings for challenging fluids like deionized water or chemical additives.
Pipe Size Flexibility
Covers ¼″ to 3″ pipe sizes, ideal for residential submetering, laboratory setups, OEM skids, and chemical process lines.
Non-Intrusive Clamp-On Installation
Pre-mounted magnetic transducers require no gel or alignment, reducing install time to under 3 minutes with zero flow disruption.
Robust Data Logging & Output Options
Internal logger records daily, monthly, and totalized flow. Easy integration with control systems.
Ready to Find the Right Flow Meter for Your Application?
Built for Engineers, By Engineers
OEM Engineers for Skid & System Integrators
- Ideal for designing miniature dosing or chemical feed systems (e.g., lab-scale skids, ultrapure water systems)
- Applicable for industries like biotech, HVAC control, or compact fluid systems
- Provides compact, non-invasive flow verification tools for QA or commissioning
- Diagnose flow in micro-zones, VAV boxes, or small chilled water circuits
Facilities Managers & Energy Engineers
- Easily monitor individual tenant water usage
- Ideal for leak detection and submetering - detects low-flow usage patterns in zones and laterals
- BTU monitoring - accurately calculates chilled/hot water energy for tenant billing and LEED compliance
- Built-in memory records usage data for tracking, optimization, and compliance reporting
- No pipe cutting needed and easily move from unit to unit
Laboratory and R&D Engineers
- Ideal for fluid researchers, chemical scientists, or lab techs in biotech or pharmaceutical industries
- Easily measure non-conductive liquids such as DI water
- Transit-time ultrasonic technology works perfectly for ultra low flows
- Non-invasive design protects purity
Chemical Process Engineers
- Verifies additive injection in lab-scale reactors or pilot plants
- Tracks minute flows with built-in alarms and integrates easily with PLCs and SCADA
- Works with chemically resistant pipe materials like PVDF, HDPE, and polypropylene
- Built-in logger supports traceable dosing logs for validation and compliance
Key Features of Our Low Flow Meters
- Pipe Size Flexibility: Covers ¼” to 3” pipe sizes, ideal for residential submetering, laboratory setups, and OEM skids.
- Fast Clamp-On Installation: Pre-mounted magnetic transducers require no gel or alignment, reducing install time to under 3 minutes—with zero flow disruption.
- Robust Data Logging: Internal logger records daily, monthly, and totalized flow—supporting trend analysis, billing, or dosing validation.
- Advanced Output Options: Integrates easily with control systems via 4–20 mA, MODBUS RTU, and alarm relays.
- Compatible with All Common Pipe Materials: Works with stainless steel, carbon steel, copper, PVC, PVDF, polypropylene, and HDPE, enabling use across mixed infrastructure and OEM builds.
- Precision at Low Flow Rates: Maintains ±2% accuracy even down to 0.1 m/s, with repeatability of ±0.8%, ensuring reliable readings for micro-dosing and leak detection.
- Thermal Energy Monitoring: Optional BTU/energy feature calculates thermal transfer in HVAC systems—ideal for building automation and energy audits.
- NIST Traceable Calibration: Shipped with certification for applications requiring regulatory compliance or QA documentation.
Technical Specifications
| Measuring principle: | Transit time ultrasonic |
|---|---|
| Flow velocity range: | 0.08 m/s ~ 10.0 m/s (15–1900 fpm) |
| Accuracy: | std ±2% RD, opt ±1% RD |
| Repeatability: | 0.8% |
| Pipe size: | 1/4" ~ 1.5" (DN08–DN40) |
| Data storage: | Daily, monthly, flow rates and totals |
| Analog output: | 4–20 mA, Maximum load: 600Ω |
| Alarm output: | OCT, Upper and lower limit alarm function (optional) |
| Communication: | RS485/Modbus |
| Power supply: | 10–24 Vdc/1A |
| Case material: | Aluminum alloy and ABS |
| Protection: | IP65 |
|---|---|
| Cable length: | 6′ (1.8m) |
| Screen: | LCD display with four touch buttons (keyboard) for setup and diagnostics, adjustments, etc. |
| Units: | Metric and imperial units are available, Cubic Meters (m3), Liters (L), USA Gallons (GAL)/hour, /min; default unit setting: m3/hr |
| Totalizer: | Six-bit digit |
| Pipe materials: | Stainless steel pipe, carbon steel pipe, copper pipe, plastic pipe |
| Ambient temperature: | (32°F~122°F) 0°C~50°C |
| Media temp: | (32°F~122°F) 0°C~50°C |
| Environment Humidity: | 0–95% relative humidity, without condensation |
How Our Low Flow Ultrasonic Technology Works
SmartMeasurement’s ALSONIC‑MINI employs transit‑time ultrasonic technology to accurately measure ultra‑low flow rates in small pipes (¼″–3″ / 8–80 mm). Rather than contacting the liquid, two magnetic clamp‑on transducers transmit ultrasonic pulses both with and against the direction of flow. By measuring the difference in transit time between upstream and downstream pulses, the meter calculates average fluid velocity and volumetric flow with ±2% accuracy and ±0.8% repeatability—including flows as low as 008 m/s.
Installation
Installation is easy and non-intrusive. A pre‑assembled circular clamp snaps onto the pipe, requiring no coupling gel or precise alignment. This enables setup in under three minutes with no system shutdown needed.
Low Flow Meter Applications
Building Automation and HVAC Systems
The ALSONIC-MINI is engineered to support BTU and chilled/hot water energy monitoring across small-diameter lines in HVAC systems. Our low flow meters’ optional thermal energy feature, 4–20 mA and MODBUS RTU outputs, and non-invasive clamp-on installation helps facility managers monitor flow and energy usage without downtime or pipe modification.
Deionized (DI) Water in Pharmaceutical Labs
Standard electromagnetic meters fail with non-conductive DI water. SmartMeasurement’s ALSONIC-MINI leverages transit-time ultrasonic technology to accurately track DI water flow without contacting the fluid. Its non-invasive, sanitary design and ±2% accuracy make it a perfect match for ultrapure process water, clean-in-place (CIP) loops, and lab-scale testing environments.
Chemical Injection & Dosing
SmartMeasurement helps engineers maintain precision in micro-dosing applications for water treatment, oil & gas, and chemical processing. With flow detection down to 0.08 m/s, alarm relay options, and NIST-traceable calibration, the ALSONIC-MINI ensures safe reagent dosing and corrosion inhibitor feed for accurate, traceable chemical delivery.
Food & Beverage Systems
The ALSONIC-MINI supports non-invasive, sanitary flow monitoring in food and beverage applications such as flavor additives, coloring agents, and low-volume CIP flows. The clamp-on form factor ensures zero contamination risk and rapid installation on both metal and plastic piping. SmartMeasurement features FDA-compliant systems, skid-mounted processing equipment, and batch consistency verification.
Submetering in Municipal Buildings
Track water consumption across departments, wings, or zones in government buildings, libraries, and public infrastructure. The ALSONIC-MINI provides daily, monthly, and totalized flow logging, empowering municipalities with actionable insights into usage patterns as well as leaks and inefficiencies, making it ideal for use cases such as water conservation initiatives, public works reporting, and tenant billing support.
How SmartMeasurement Handles Use Case Environments
| Application | Challenge | SmartMeasurement Solution |
|---|---|---|
| Submetering in Buildings | Detecting low-use or leak-by flows | Clamp-on design + daily logging for easy deployment and audits |
| Lab-Scale DI Water Systems | Measuring non-conductive, ultra-low flow | Transit-time tech + non-contact = precise DI monitoring |
| Chemical Skids / Dosing Systems | Verifying precise micro-dosing | ±2% accuracy with alarm outputs for dosing control |
| HVAC Branch Loops | Measuring BTU energy in low-flow lines | Optional BTU calc with temp sensors + SCADA-ready outputs |
| Food Additive Injection | Needing sanitary, flexible meters | Clamp-on install = no contamination risk, field-swappable |
| Fire Pump Test Loops | Measuring recirculation bypass flow | Portable clamp-on fits tight spaces and low-demand flow |
| Mobile Environmental Monitoring | Low-volume pilot test flows | Lightweight, portable, installs in minutes |
ALSONIC-MINI Low Flow Meter FAQs
What is a low flow meter?
A low flow meter is a precision instrument designed to accurately measure small volumetric flow rates, typically below 1 GPM (gallon per minute).
What is the least count of a flow meter?
“Least count” refers to the smallest measurable change in flow rate that a meter can detect. For the SmartMeasurement ALSONIC-MINI, the least count depends on pipe size and velocity range, but it’s typically able to measure down to 1 milliliter per second (mL/s).
Is the ALSONIC-MINI suitable for precise metering and flow validation?
Yes, with a ±1.5% accuracy (even better in steady flow), the ALSONIC-MINI is engineered for applications requiring high repeatability and stable measurement. It is perfect for use cases such as quality control, calibration labs, and OEM test benches.
How easy is it to install on small or narrow pipework?
The ALSONIC-MINI uses miniature clamp-on transducers with flexible sensor mounting to fit tiny diameter piping (¼″–3″). There’s no cutting or interruption to the flow, and alignment is aided by visual signal strength feedback.
What flowmeter is used for low flow rates?
For low flow rate applications—especially below 0.5 GPM—engineers turn to clamp-on transit-time ultrasonic flow meters like SmartMeasurement’s ALSONIC-MINI. This device offers ±2% accuracy for ultra-low flows in pipes as small as ¼”, making it ideal for applications like chemical dosing, deionized water monitoring, and submetering. It installs non-invasively in under 3 minutes, without disrupting the flow or cutting into the pipe.
What is the minimum flow in a water meter?
The minimum measurable flow of a SmartMeasurement ALSONIC-MINI depends on pipe size, but in a 1//4 ″ line, it can detect flow as low as 0.1–0.08 m/s, which corresponds to fractions of a liter per minute.
Does it offer industrial outputs for system integration?
Yes. Despite its compact size, the ALSONIC-MINI supports 4–20 mA, pulse output, and RS‑485 Modbus, making it fully compatible with PLC, SCADA, and building automation systems.
What is the long-term maintenance requirement?
Maintenance is minimal. The non-invasive, no-moving-parts design means no fouling or no pressure loss, and zero contact with the fluid. It’s ideal for sterile or high-purity applications and reduces long-term service costs.
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