Single-Path Ultrasonic Flow Meter (±1.0 %, DN25–DN2000)
Same Accuracy on Inline, Wall-Mount, and BTU Versions
Transit-time, 0.5 to 5 m/s, response 500 ms
24 V DC, 5 W. IP54 transmitter, IP68 wetted transducer
Modbus RTU, 4-20 mA, OCT pulse, relay
- Lowest-cost option in the single-path line; about 30 % below the inline ±0.5 % model at the same DN.
- LCD 2.4-inch with 4-direction rotation; reads m³/h, LPM, mL/min, GPM, LPH.
- Covers most inline plant measurement; lines above DN2000 go to the wider-range model.
The Single-Path Ultrasonic Flow Meter is a transit-time instrument for liquid service, DN25 to DN2000. A transducer pair times the upstream and downstream transit difference along a single path. Accuracy is uniform ±1.0 % of reading at 0.5 to 5 m/s across all four configurations; C8 inline or W8 wall-mount, with or without the PT100 BTU pair. Modbus RTU, 4-20 mA, OCT pulse, relay. 24 V DC. 5–7 business days from the factory.
Benefits
- Lowest cost in the single-path line. Sits roughly 30 % below the inline ±0.5 % model at the same DN. Right pick when ±1.0 % is enough; trending, dosing, cooling-water primary, secondary metering.
- Uniform ±1.0 % across all four configurations. Inline or wall-mount, with or without BTU pair; same spec. No accuracy step-down when adding the wall-mount or BTU.
- DN25 to DN2000; covers most inline plant measurement. Cooling-water primary, chilled-water, glycol-water, chemical reagent dosing. Lines above DN2000 go to the wider-range model.
- LCD 2.4-inch display, 4-direction rotation. Reads m³/h, LPM, mL/min, GPM, LPH. Mount the transmitter any orientation; display rotates to match.
- 24 V DC industrial bus, 5 W. Modbus RTU + 4-20 mA + OCT pulse + relay. Pre-configured slave address. IP54 transmitter, IP68 wetted transducer.
Configure your build.
Build a model code from DN, install style, BTU option, output, and power. Accuracy stays ±1.0 % across all configurations.
Your configuration
PF-UFM-U6-DN100-C8-FLOW-STD-MOD-DC
DN100 commercial / HVAC primary, C8 integral inline, flow-only (no PT100 pair), standard medium-temperature (-40 to +80 deg C), RS-485 Modbus RTU + 4-20 mA + OCT pulse, 24 V DC. Accuracy ±1.0 % across all configs.
Estimated unit price
$ 1,100
Request engineering quote
Request datasheet
Applications
🏭
Plant cooling + dosing lines
DN50 to DN800 cooling-water primary, chemical reagent dosing, glycol-water blends. ±1.0 % is sufficient for trending and routine plant measurement at lower cost.
📦
Volume OEM skid
White-label skid build where the spec calls for ±1.0 % inline. Lowest model in the single-path line. Sized quote within one business day.
🔁
Secondary or back-up metering
Verification meter alongside a primary ±0.5 % meter; batch dosing reconciliation; redundancy on critical lines where one ±0.5 % already runs.
🔥
District-heat substation (with BTU)
Optional PT100 pair adds kWh / MJ / BTU at the same ±1.0 %; no step-down. Go to ±0.5 % counterpart for billing-grade BTU.
Full specifications.
| Measurement principle | Single-path transit-time ultrasonic; one acoustic path between a transducer pair; firmware times the upstream and downstream transit difference |
|---|---|
| Channels | 1 acoustic path |
| Nominal diameter | DN25 to DN2000 |
| Accuracy | ±1.0 % of reading at velocity 0.5 to 5 m/s; uniform across inline / wall-mount / with-BTU / without-BTU |
| Linearity | ±1.0 % at velocity 0.5 to 5 m/s |
| Repeatability | 0.20 % |
| Velocity range | 0.1 to 12 m/s operating; accuracy spec ±1.0 % within 0.5 to 5 m/s |
| Response time | 500 ms |
| Install style | C8 integral inline body (transmitter on the flow body) OR W8 split-body wall-mount (transducer set on the line, remote transmitter on the wall) |
| Optional BTU pair | PT100 supply + return pair; on-board firmware solves E = integral of (m-dot x Cp x delta-T) dt; output kWh / MJ / BTU selectable; accuracy unchanged at ±1.0 % |
| Display | LCD 2.4-inch IPS, 320 × 240 resolution, 4-direction rotation; unit selection m³/h, LPM, mL/min, GPM, LPH |
| Output; analog | 4-20 mA, max load 600 ohm |
| Output; digital | RS-485 Modbus RTU |
| Output; other | OCT pulse + high / low alarm; relay 30 V DC at 1 A, switching frequency under 2 Hz |
| Power | 24 V DC, 5 W |
| Medium | Single-phase liquid, 100 % pipe-fill; water, aqueous solution, chemical reagent; suspended solids 4 % or less |
| Medium temperature | −40 to +80 deg C (sensor head) |
| Ambient temperature | −40 to +60 deg C transmitter; −40 to +80 deg C sensor head |
| Ingress protection | IP54 transmitter housing; IP68 wetted transducer head |
| Process connection | Flange ANSI B16.5 / EN 1092-1 / GB/T 9119 (specify at order) |
| Hazardous area | Not declared on this model; route Ex-classified service to clamp-on or insertion ultrasonic model with CNEX Ex d IIC certificate |
| Compliance ships standard | Calibration record with each meter (serial number + tested flow range); notified-body custody-transfer certificate is buyer-arranged |
| Lead time | 5–7 business days from factory |
Installation rules.
Single-path needs more straight-pipe than multi-path. Five rules.
- 10D upstream, 5D downstream straight-pipe (D = pipe diameter). Single-path reads asymmetric profile as bias; hold 20D after pumps. Short straight-pipe? Go to multi-path counterparts.
- Mount the transducer pair at 12 and 6 o’clock on horizontal lines. Both transducers stay wetted; avoids air-pocket bias at the crown.
- Pipe must stay 100 % liquid-filled. Air pockets falsify the transit-time signal. Closed loops need a vent on the loop high point.
- Mount W8 transmitter on a stable wall, −40 to +60 deg C ambient. IP54 housing; plant room, not outdoor submerged service.
- Configure register map and slave address at commissioning. Factory pre-configures from BMS or DCS spec. Record both in the commissioning log.
Frequently asked questions
How does the meter work?+
A transducer pair sits on opposite sides of the pipe at a fixed angle. Each transducer alternates as transmitter and receiver, firing acoustic pulses upstream and downstream along the same path. The pulse traveling with the flow arrives faster; the pulse against the flow arrives slower. The firmware times the transit difference and returns line velocity, which multiplied by the cross-section area gives volumetric flow.
Why pick ±1.0 % over ±0.5 % counterparts?+
Price and uniformity. This meter sits roughly 30 % below the inline ±0.5 % model at the same DN. Accuracy is also uniform; ±1.0 % across all four configurations (inline or wall-mount, with or without BTU pair), so wall-mount and BTU buyers do not see a further accuracy step-down. ±1.0 % is sufficient for trending, dosing, cooling-water primary, secondary metering, batch verification. For custody-grade or precision billing, go to the ±0.5 % counterparts.
What is the straight-pipe rule?+
10D upstream, 5D downstream as the working rule for single-path. After a pump or a double elbow out-of-plane, hold 20D upstream. A single-path meter sees the upstream profile asymmetry as a bias; if the install cannot hold 10D, go to the 2-path averaging model (5D/3D footprint) or the 4-path model (severe-disturbance tolerance).
Can the same body meter heat energy as well as flow?+
Yes, with the optional PT100 supply + return pair. The transmitter accepts two PT100 inputs and runs the BTU calorimetry firmware that solves E = ∫(ṃ × Cp × ΔT) dt. Output is selectable between kWh, MJ, and BTU on the display and on the 4-20 mA energy-rate channel. Accuracy stays at ±1.0 % with the BTU pair; no further step-down. Specify with-BTU at order.
What ships in the package and what is the lead time?+
The package ships with the flow body (C8) or transducer set (W8), the transmitter with a 2.4-inch LCD, signal cable (length factory-set per order), the calibration record (serial number, tested flow range), and a pre-configured Modbus register map and slave address. Optional PT100 BTU pair adds two temperature sensors plus coupling paste and stainless straps. Lead time is 5 to 7 business days from the factory.
Need help spec’ing this meter?
Send DN, service liquid, install style, and BTU option. Sized quote within one business day. Lead time 5–7 business days.