Guiyang.bai@honno-auto. com
86-13840589744
Compact inline vortex flow meter that measures BOTH flow and temperature in one instrument. It works on the Kármán vortex street principle: a bluff body generates alternating vortices downstream whose frequency is proportional to the flow velocity, and a piezoelectric element counts the vortex pulses — there are no mechanical moving parts, so there is no wear, no drift and accuracy reaches ±2% FS. The self-luminous OLED display (128×64) shows instantaneous flow, pipe size, engineering unit and temperature at a glance, and three panel keys (SET / ▲ / ▼) make flow alarm and temperature alarm points easy to set on site; POW/AL1/AL2 LEDs show power and alarm status. Outputs on OUT1–OUT3 are user-configurable: flow alarm, temperature alarm, flow 4–20 mA or temperature 4–20 mA, with PNP/NPN alarm contacts and optional RS485 communication — easy to wire directly into a PLC or control system. Both ends use a union design for quick installation and removal, and sensors can be mounted in parallel for a very compact layout. Wetted base in 304 stainless steel with an aluminium-alloy housing; pressure rating PN10 (1.0 MPa); medium temperature 0–100 ℃, −10–90 ℃ or customised; temperature accuracy ≤1 ℃; supply 24 VDC (3 W); process connections G1/2″ internal thread for DN8–DN15, G3/4″ for DN20 and G1″ for DN25; protection class IP67; ambient −20…60 ℃, <85% RH. Flow ranges: DN8 1–20 L/min, DN10 3–30 L/min, DN15 5–50 L/min, DN20 8–80 L/min, DN25 12–120 L/min. For best accuracy allow ≥10×DN straight pipe upstream and ≥5×DN downstream.
The HNF40-AC is a compact inline vortex flow meter based on the Kármán vortex street principle. A bluff body sheds alternating vortices downstream; the vortex frequency is proportional to flow velocity, and a piezoelectric element counts the pulses to compute flow rate.
One instrument measures both flow and temperature. There are no mechanical moving parts – no wear, no drift, accuracy ±2% FS. The self-luminous 128×64 OLED shows instantaneous flow, pipe size, engineering unit and temperature at a glance; three keys (SET/▲/▼) set flow and temperature alarms on site. Both ends use a union design for quick installation and removal, and sensors can be mounted in parallel for a very compact layout.
Size: DN8 – DN25 Flow: 1 – 120 L/min Accuracy: ±2% FS · Temp ≤1 °C Outputs: dual 4-20mA · PNP/NPN alarm · RS485 Protection: IP67 · aluminium housing · 304 base
Applications: semiconductor equipment (etching, grinding, slicer, CVD), high-frequency quenching cooling water, spot-welder cooling & low-flow detection, machine-tool water-soluble coolant, new energy / PV / energy storage, petrochemical, power, metallurgy & steel, papermaking, food processing, water treatment, battery plants, fire protection, PLC integration, circulating cooling water.
Select this model when all of the following conditions are met:
The medium is a clean single-phase liquid (industrial water, water-soluble coolant, oils) and you need inline flow and temperature measurement.
Pipe size is DN8–DN25 (G1/2", G3/4", G1" female thread) and flow is between 1 and 120 L/min.
Medium temperature is 0–100 °C (or −10 to 90 °C / custom); ambient −20 to 60 °C.
You need dual 4–20 mA (flow + temperature) into PLC/DCS, plus PNP/NPN alarm contacts.
You want on-site OLED readout and push-button alarm setting without a handheld programmer.
Space is tight and you prefer union ends for quick removal or parallel mounting.
Please consult us first if: pipe is larger than DN25, the liquid carries many bubbles or solids, temperature exceeds 100 °C, explosion protection or higher pressure rating is required, or the medium needs special wetted materials.
Kármán vortex detection with a piezoelectric element – no rotating mechanical parts, no wear, no drift. Flow accuracy ±2% FS and temperature accuracy ≤1 °C, long-term maintenance-free.
OUT1–OUT3 are user-configurable as flow alarm, temperature alarm, flow 4–20 mA or temperature 4–20 mA. PNP/NPN alarm contacts go straight into PLC digital inputs – eliminating a separate temperature transmitter's cost and space.
The 128×64 organic LED display is sharp and high-resolution, showing instantaneous flow, pipe size, unit and temperature together. Three keys drive a simple drop-down menu – no menu codes to memorise – and a QR code on the unit links to online engineer installation guidance.
Both ends are G-thread unions removable with a 28 mm spanner; 304 stainless base and aluminium housing resist corrosion and interference; IP67 suits wet, washdown environments.
| Model | HNF40-AC Vortex Flow-Temperature Sensor (inline) |
|---|---|
| Principle | Kármán vortex street; piezoelectric element counts vortex pulses; no mechanical moving parts |
| Medium | Clean liquids (industrial water, water-soluble coolant, oils, etc.) |
| Accuracy | Flow ±2% FS; temperature ≤1 °C |
| Temperature range | 0–100 °C, −10–90 °C, or custom |
| Display | OLED 128×64 self-luminous; instantaneous flow, pipe size, unit and temperature on one screen |
| Operation | Three keys SET/▲/▼ to set flow & temperature alarms; POW/AL1/AL2 LEDs |
| Switch delay | ON ≥5 s (settable 1–3 s); OFF ≥5 s (settable 1–5 s) |
| Outputs | Alarm contact + 4–20 mA current + RS485; alarm type NPN / PNP; contact rating 24 VDC / 50 mA |
| Output configuration | OUT1/OUT2/OUT3 user-selectable: flow alarm, temperature alarm, flow 4–20 mA, temperature 4–20 mA |
| Electrical connection | 5-pin waterproof aviation plug with shielded cable |
| Insulation | ≥50 MΩ at 100 VDC |
| Power | 24 VDC, approx. 3 W |
| Process connection | G1/2" female (DN8–DN15), G3/4" female (DN20), G1" female (DN25); union on both ends |
| Housing | Aluminium alloy housing + 304 stainless steel base |
| Ambient | −20 … 60 °C, < 85% RH |
| Protection | IP67 |
| Size | Flow range | Process thread |
|---|---|---|
| DN8 | 1 – 20 L/min | G1/2" female |
| DN10 | 3 – 30 L/min | G1/2" female |
| DN15 | 5 – 50 L/min | G1/2" female |
| DN20 | 8 – 80 L/min | G3/4" female |
| DN25 | 12 – 120 L/min | G1" female |
Straight-run requirements (best accuracy, reduced turbulence & bubble effects):
General: upstream ≥10×DN, downstream ≥5×DN.
Single 90° elbow: upstream ≥20×DN, downstream ≥5×DN.
Two 90° elbows in same plane: upstream ≥25×DN; in different planes: upstream ≥40×DN.
Reducer: upstream ≥15×DN; expander: upstream ≥20×DN.
Fully open valve: upstream ≥20×DN; half-open valve: upstream ≥50×DN.
Union ends allow fast installation and removal with a 28 mm spanner; sensors may be mounted in parallel to save space. After power-on, the OLED shows instantaneous flow and temperature; use SET to enter the menu and set flow/temperature alarm points and switch delays. Wire via the 5-pin shielded aviation plug according to the OUT configuration.
Dual 4–20 mA: can map flow and temperature separately into PLC/DCS analogue modules.
PNP / NPN alarm contacts: OUT1/OUT2/OUT3 configurable as flow or temperature alarm, contact 24 VDC / 50 mA, direct to PLC digital inputs or indicator lights.
RS485: Modbus-ready for multi-sensor bus integration into SCADA.
Adjustable switch delay: ON 1–3 s, OFF 1–5 s to avoid nuisance alarms from short fluctuations.
5-pin shielded aviation plug: brown (+V), blue (−V), black (OUT1), grey (OUT2), white (OUT3), with ground shield wire to reduce interference.
Low-flow alarms can directly protect spot-welders and high-frequency quenching cooling circuits: below threshold, the PNP/NPN contact trips and interlocks the machine.
Monitors cooling-water flow and temperature on etchers, grinders, slicers and CVD tools; dual 4–20 mA feeds the equipment PLC and triggers alarms to protect precision chambers.
Real-time water-flow monitoring on quenching power supplies and spot welders; the low-flow alarm contact interlocks shutdown to prevent overheating.
Flow and temperature on machining centres and grinders; signals feed the shop-floor MES for tool protection and process traceability.
Cooling loops and liquid circuits on battery lines, PV modules and energy-storage systems; IP67 suits wet workshop environments.
Circulating cooling-water metering in petrochemical, power plants, steel mills, papermaking, food, water treatment and fire-protection systems; RS485 enables central monitoring.
To confirm the correct HNF40-AC configuration, please provide: medium name and temperature range, normal and maximum flow, pipe size and thread (G1/2, G3/4, G1), preferred outputs (dual 4-20 mA, PNP/NPN alarm, RS485), supply voltage and site environment. If necessary we will request upstream/downstream straight-run length and medium viscosity.
DN8: 1–20 L/min; DN10: 3–30 L/min; DN15: 5–50 L/min; DN20: 8–80 L/min; DN25: 12–120 L/min, with G1/2", G3/4" and G1" female threads.
Yes. OUT1–OUT3 are user-defined as flow 4–20 mA, temperature 4–20 mA or PNP/NPN alarm contacts, feeding both analogue and digital PLC channels.
Yes. G-thread unions on both ends are removable with a 28 mm spanner without disassembling the whole pipe; units can be mounted in parallel to save space.
General: ≥10×DN upstream and ≥5×DN downstream; single elbow 20×DN, same-plane double elbow 25×DN, different-plane double elbow 40×DN, half-open valve 50×DN upstream.
PNP/NPN alarm contacts (24 VDC / 50 mA), dual 4–20 mA current, and RS485 Modbus; wired via a 5-pin shielded aviation plug.
HNF40-AC Vortex Flow-Temperature Sensor Datasheet (PDF)
Insert the download link here after uploading the PDF to your website.
Send us medium & temperature, normal flow, pipe size & thread, output type, and we will confirm whether HNF40-AC is suitable and recommend the right size and output configuration before quotation.
Submit your application details »Contact: HongNuo
Phone: 13840589744
Tel: 86-13840589744
Email: Guiyang.bai@honno-auto. com
Add: Zhongguancun Innovation Center, No. 28 Huahai Road, Shenyang Economic and Technological Development Zone, Liaoning Province
We chat
