Oxygen Flow Meter
Pure Oxygen TMF Build
Accuracy of ±1.0% of rate
Temperature service −45 to +150 °C
Turndown ratio of 1:1200
- Line sizes DN10 to DN300
- Working pressure ≤ 1.6 MPa standard, up to 6.3 MPa on request
- Sensor wetted parts 316L stainless or Hastelloy C
One thermal-mass meter replaces the vortex + T transmitter + P transmitter + flow computer stack.
The traditional way to meter oxygen on an industrial header is a vortex (or DP-orifice) + temperature transmitter + pressure transmitter + flow computer running a compressibility table. That stack has four instruments to calibrate, more cabling, and more failure modes than the TMF-O2 has parts. Below is a typical DN100 ASU outlet priced at factory-direct level over a 3-year horizon, not including installation labor.
Vortex + T + P + Flow Computer Stack
- Vortex flow meter (DN100, Ex d) $2,180
- Temperature transmitter (Pt1000, Ex d) $580
- Pressure transmitter (gauge, Ex d) $640
- Flow computer (compressibility / Z-factor compute, certified) $1,860
- 4 calibration certificates + integration loop check $520
- Annual recal × 4 instruments × 3 yrs $1,520
TMF-O2 Single Instrument
- TMF-O2 DN100, ±1.0% of rate, 4-20 mA + HART $2,800
- Factory K-factor pre-loaded for oxygen included
- ISO 9001 calibration certificate with each meter included
- CE + CNEX + CNEX certificates included
- Annual recal × 1 instrument × 3 yrs $540
- Continuous audit standard flow log (built-in) included
The Oxygen Thermal Mass Flow Meter reads mass flow directly from heater power across ASU outlet headers, oxygen lance feeds, oxy-fuel burners, and aeration mains. Outputs Nm³/h or kg/h on the 4-20 mA loop with no external T+P stack.
Standard build runs 316L wetted parts and Ex d flameproof housing. Hastelloy C is available for chloride or trace-contamination service. CNEX Ex d IIC T6 Gb hazardous-area protection ships on every order.
Benefits
- Direct mass flow: thermal-dispersion outputs Nm³/h on 4-20 mA; replaces vortex + T + P + flow-computer stack.
- ±1.0 % of rate: standard build with ±0.5 % repeatability; sufficient for ASU billing, oxy-lance, aeration kWh accounting.
- 0.1 Nm/s low-flow detection: resolves overnight ASU idle and small leak drift that vortex (3–4 m/s minimum) reads as zero.
- 1:1200 velocity turndown: one model spans morning ramp through ASU peak; no parallel-meter bypass piping.
- Hastelloy C option: 316L for clean industrial O₂; Hastelloy C for chloride or moisture carry-over from upstream packing.
- Hazardous-area: CNEX Ex d IIC T6 Gb (flameproof, Zone 1) standard; IP65/66/67 and EMC 2014/30/EU.
- Lead time: 5–7 business days from the factory.
Quick specifications.
| Measurement Principle | Thermal dispersion (constant-temperature-difference / CTD mode); two RTDs, direct mass flow from heater power |
|---|---|
| Execution Standard | GB/T 32201-2015; Gas Flow Meters |
| Line Sizes | DN10 – DN300 (3/8″ – 12″) inline full-bore |
| Direct Mass Output | Yes; Nm³/h or kg/h on 4-20 mA loop · zero external T+P compensation required |
| Accuracy | ±1.0% of rate grade A standard · ±1.5% of rate grade B economy · ±0.5% repeatability |
| Velocity Range | 0.1 to 120 Nm/s · 1:1200 turndown across the product line, 1:600 practical low-flow build |
| Low-flow detection | 0.1 Nm/s; resolves header leak drift and night-time branch demand |
| Response Time | 1 second |
| Pressure Loss | Negligible above DN80 (sensor wall-mounted, no bluff body, no orifice) |
| Pressure | ≤ 1.6 MPa standard · 2.5 / 4.0 / 6.3 MPa / ANSI 150–600 LB on request |
| Medium Temperature | -45 to +150 °C (covers ASU outlet, plant distribution, oxygen lance feed) |
| Sensor Wetted Material | 316L stainless standard · Hastelloy C optional |
| Body Material | 304 SS standard · 316 · Hastelloy C optional |
| Connection Options | Wafer flanged · Flanged · Tri-clamp · NPT / G-thread (optional) |
| Output Signals | Pulse · 4–20 mA + HART · RS485 Modbus RTU · PROFIBUS · Foundation Fieldbus · 4G GPRS / IoT |
| Power Supply | 24 V DC or 220 V AC · ≤ 18 W maximum |
| Hazardous Area | Ex d flameproof standard; standard for the TMF series |
| Ingress Protection | IP65 / IP66 / IP67 (optional) |
| Approvals | CE · CNEX · ISO 9001 calibration certificate with each meter |
Configure and add to cart.
Select your specs; the configurator generates a TMF model code per the 12-position table and a ballpark price. Submit to engineering for verified sizing against your ASU outlet, plant distribution header, oxygen lance feed, or aeration main within 4 business hours.
Your Configuration
✓ Factory K-factor pre-loaded for oxygen
✓ ISO 9001 calibration certificate with each meter
✓ Reply within 4 business hours
Oxygen measurement across process industries
Steel BOF & Oxy-Fuel
BOF lance flow on integrated steelmakers; oxy-fuel cutting on casters; glass float furnaces; EAF O₂ injection.
Hospital / Medical Supply
ASU inlet/outlet headers, PSA/VPSA generator sub-measurement, bulk-to-manifold reconciliation.
Wastewater BOD Aeration
Activated-sludge O₂ enrichment of diffuser headers (replacing air blowers on peak-BOD zones), MBBR and IFAS retrofits.
Ozone Feed / Aquaculture
Ozone generator O₂ feed (drinking water, pulp bleaching) and aquaculture DO enrichment on closed-recirculating fish farms.
Specifications
Performance
| Accuracy | ±1.0 % of rate grade A · ±1.5 % of rate grade B · ±0.5 % repeatability |
|---|---|
| Velocity range | 0.1 to 120 Nm/s (1:600 practical, 1:1200 across product line) |
| Low-flow detection | 0.1 Nm/s; resolves ward-level medical drift, branch-level wastewater leakage |
| Temperature measurement | Pt1000 reference RTD, integrated · ±0.3 °C |
| Response time | 1 second |
| Pressure loss | Negligible > DN80 (< 1 kPa at rated flow) · wall-mounted probe, no bluff body, no impulse lines |
| Power supply | 24 V DC or 220 V AC · ≤ 18 W maximum |
Process & Environment
| Medium | Gaseous oxygen; ASU outlet, PSA / VPSA generator output, cryogenic LOX vaporizer output, industrial oxygen distribution |
|---|---|
| Pressure range | ≤ 1.6 MPa standard · 2.5 / 4.0 / 6.3 MPa / ANSI 150–600 LB on request |
| Medium temperature | -45 to +150 °C |
| Ambient temperature | -35 to +65 °C · 5% to 90% RH · 86 to 106 kPa atmospheric |
| Hazardous area | Ex d flameproof standard (standard for TMF series) |
| Ingress rating | IP65 / IP66 / IP67 (optional) |
Sensor & Outputs
| Sensor pair | Two RTDs: one temperature reference, one heated to fixed ΔT |
|---|---|
| Compensation | Built-in: heat-balance physics gives Nm³/h directly, no T+P transmitters required |
| Analogue output | 4–20 mA + HART (multidrop) |
| Pulse output | Pulse equivalent for totalizer cross-check |
| Digital output | RS485 Modbus RTU · PROFIBUS · Foundation Fieldbus · 4G GPRS / IoT |
| Local display | LCD: working flow, Nm³/h, totalizer, kg/h, status |
| Signal distance | Sensor to remote display: up to 1000 m |
Materials & Construction
| Sensor wetted parts | 316L stainless standard · Hastelloy C option |
|---|---|
| Body material | 304 SS standard · 316 · Hastelloy C optional |
| Connection options | Wafer flanged · Flanged · Tri-clamp · NPT / G-thread |
| Housing | Cast aluminium with polyester anti-corrosion coating · Ex d flameproof certified |
| Electrical entry | M20 × 1.5 internal thread or 1/2″ NPT |
| Net weight (DN100) | ~ 9.2 kg integral, PN16 flange, 316L |
Oxygen flow range by pipe size
Oxygen flow range in Nm³/h referenced to GB/T 3102.8 industrial conditions (20 °C, 101.325 kPa). O₂ at the reference condition has density 1.331 kg/Nm³; multiply the Nm³/h column by 1.331 to read kg/h. Column “kg/h typical” uses the typical-range midpoint. Medical and aquaculture lines typically sit in the lower half of the range; steel BOF mains and wastewater aeration in the upper half. Engineering validates your sizing against the VPSA / LOX vaporizer output and end-use demand profile.
| Pipe size | Minimum (Nm³/h) | Typical range (Nm³/h) | Maximum (Nm³/h) | kg/h typical |
|---|---|---|---|---|
| DN10 (3/8″) | 0.2 | 3 – 22 | 40 | 4.0 – 29 |
| DN15 (½″) | 0.4 | 5 – 40 | 65 | 6.7 – 53 |
| DN25 (1″) | 1 | 15 – 120 | 175 | 20 – 160 |
| DN40 (1½″) | 2 | 40 – 320 | 450 | 53 – 426 |
| DN50 (2″) | 3 | 60 – 420 | 600 | 80 – 559 |
| DN80 (3″) | 6 | 150 – 1,050 | 1,500 | 200 – 1,398 |
| DN100 (4″) | 10 | 230 – 1,610 | 2,300 | 306 – 2,143 |
| DN150 (6″) | 22 | 520 – 3,640 | 5,200 | 692 – 4,845 |
| DN200 (8″) | 40 | 900 – 6,300 | 9,000 | 1,198 – 8,385 |
| DN250 (10″) | 62 | 1,450 – 10,150 | 14,500 | 1,930 – 13,510 |
Installation
Five rules keep the install from drifting on the leak floor.
- Send gas service and operating range at order; factory K-factor depends on medium (ASU outlet, LOX vaporizer, lance, aeration), pressure and temperature.
- 10×DN upstream, 5×DN downstream; clean full-bore pipe from the last fitting.
- Wire only the loop you need; T+P read on-board; field wiring is just 4-20 mA, RS485, or HART back to the DCS.
- Follow Ex d wiring rules; do not modify the Ex d circuit, components, or protection type.
- Keep clear of magnetic and dirty-power sources; no shared power with VFDs, welding sets, large motors, transformer banks.
Oxygen thermal mass meter FAQ
Sizing an O₂ build for ASU, lance, aeration, or distribution?
Send pipe size, source, O₂ purity, pressure, design Nm³/h. Engineer replies with sized range, model code, price in 4 hours.