Series-PUF

Supported Applications

The Dwyer Series PUF Portable Ultrasonic Flowmeter Kit measures liquid flow in closed pipes using non-invasive, clamp-on transducers. The instrument utilizes ultrasonic transit-time difference techniques to determine volumetric flow and linear velocity without requiring pipe penetration or process interruption.

Documented applications include the measurement of:

• Clean liquids or oils with less than 3% by volume particulate content
• Cloudy liquids such as river water and effluent
• Cleaner liquids including demineralized, potable, treated, and seawater

The series is designed for pipes constructed of carbon steel, stainless steel (SS), copper, UPVC/PVDF, concrete, galvanized steel, mild steel, glass, or brass.

Operating Conditions & Performance

The Series PUF operates with a process temperature range of -4 to 275°F (-20 to 135°C). The converter enclosure is rated IP54, while the transducers are rated IP51. Power is supplied by an internal, factory-replaceable (1) 5-Cell NiMH battery or via a 9-24 VDC external source.

Performance specifications vary based on flow velocity and pipe inside diameter:

• Accuracy for Pipe ID > 2.95 in (75 mm): ±0.5 to 2% of flow reading at velocities > 0.66 ft/s (0.2 m/s)
• Accuracy for Pipe ID 0.512 to 2.95" (13 to 75 mm): ±3% of flow reading at velocities > 0.66 ft/s (0.2 m/s)
• Accuracy for Velocities < 0.66 ft/s (0.2 m/s): ±6% of flow reading

The series supports a linear velocity measurement range of 0.33 to 65.62 ft/s (0.1 to 20 m/s) with a response time of < 500 ms and repeatability of ±0.5% of measured value or ±0.066 ft/s (0.02 m/s).

Configuration Options

The Series PUF is available in data logging configurations with specific pipe size envelopes:

• PUF-1001: Supports pipes from 0.5 to 78 inches (13 to 2000 mm) outside diameter
• PUF-1002: Supports pipes from 0.5 to 4.5 inches (13 to 115 mm) outside diameter

The kit includes a converter with a graphic display and backlighting, transducers, holders, cables (6.56' / 2 m), chains, coupling grease, a ruler/guide rail, test block, carrying case, and power supply.

Output & Communication Options

The instrument provides multiple output configurations:

• Analog Output: One opto-isolated selectable signal (4-20 mA, 0-16 mA, or 0-20 mA) with a maximum load resistance of 620 Ω. Error current is configurable as 0-26 mA.
• Pulse Output: One opto-isolated MOSFET relay (150 mA max), supporting up to 500 pps or 200 Hz.
• Digital Communication: USB Virtual Com. Port and RS232 connection via multi-pin Lemo plugs.

An optional NIST traceable calibration certificate (NISTCAL-FU) is available for the series.

Key Product Differences

The Series PUF distinguishes itself from the standard PUB version by including data logging capability. Both series utilize transit-time difference measurement, but the PUF models are configured specifically for portable field use with integrated battery power and carrying cases. The available variants differ primarily in their maximum pipe size capacity: the PUF-1001 covers larger diameters up to 78 inches (2000 mm), while the PUF-1002 is limited to smaller pipes up to 4.5 inches (115 mm).