A portable clamp-on Doppler flow meter for the fluids transit-time cannot see: sludge, slurry, raw wastewater and aerated streams. Pipe ID 0.5″ to 500″.
SKU C6PF
Your fluid has solids or bubbles in it. If it is clean, buy transit-time — Doppler will give you nothing.
A transit-time meter fires a pulse across the fluid and times it. It needs the fluid acoustically clear. Fill it with solids or bubbles and the pulse scatters — the meter loses signal and drops out.
A Doppler meter measures the frequency shift of sound bouncing off particles carried in the flow. It needs reflectors. In clean water there is nothing to reflect off and it reads nothing at all.
They fail at exactly the job the other one does. This is physics, not a product tier. Full comparison →
Doppler has a set of insensitivities that are genuinely useful on a dirty line. The C6 is unaffected by changes in temperature, viscosity, specific gravity, or the speed of sound in the liquid. The liquid does not need to be electrically conductive — which is where a magnetic flow meter would stop.
Think about what that rules out. A sludge line whose solids loading changes hour to hour changes its density, its viscosity and its speed of sound. A transit-time meter has to cope with all of that. The Doppler meter is measuring a frequency shift and simply does not care.
This is the specification that makes the C6 work where other meters cannot go. The transducer belongs on the pipe — in the wet well, at the bottom of the shaft, in the pit. The display belongs somewhere a human can safely stand. Five thousand feet of separation is a lot of freedom about where those two places are. The transducer is potted IP68 and submersible to 200 ft; it is built to be underwater and stay there.
1%, and the datasheet says “a function of flow profile.” Believe that. Doppler measures the velocity of the reflectors, and reflectors are not evenly distributed in a pipe carrying slurry — heavier solids concentrate low, bubbles rise. What the meter sees depends on where in the profile its beam is looking.
Doppler is excellent for trending, control and relative change. It is not the instrument for custody transfer. If someone is being billed off the number, we will steer you elsewhere and tell you why. A NIST certificate of calibration is available.
| Technology | Ultrasonic Doppler, clamp-on (non-invasive). Reflects off suspended solids or entrained gas. |
|---|---|
| Pipe ID range | 0.5 – 500 in (12 – 12,000 mm) |
| Pipe materials | PVC, HDPE, plastic, steel, rubber, concrete, copper |
| Accuracy | 1% (a function of flow profile) |
| Linearity | ±0.5% |
| Repeatability | ±0.1% |
| Flow range | 0 – 50 ft/s (15 m/s). Resolution 0.1 ft/s (0.03 m/s). |
| Fluid temperature | −30 to 90 °C; up to 250 °C with special fittings |
| Transducer | Potted IP68 non-metallic, submersible to 200 ft. Temp −70 °F to +185 °F. 500 °F heat-sink option. |
| Insensitive to | Changes in temperature, viscosity, specific gravity, or speed of sound. Liquid need not be conductive. |
| Outputs | Digital pulse train (0–12 V), 4–20 mA (max 1200 ohm), RS232 via DB9. Hi/low limit alarms, batch control. |
| Power | Isolated, regulated module. 100–240 VAC @ 1.0 A — 12 VDC. AC or DC, solar or battery. |
| Display enclosure | NEMA 4X hinged, IP64 (+4 °F to +140 °F) |
| Dimensions | 7 × 5 × 3 in |
| Weight | 8 lb |
| Totalizer | 12-digit LCD, memory backup 99 yr+ |
| Cable length | 25 ft standard; 25 ft – 5000 ft optional (signal cable to 1500 m) |
| Coupling | Grease, sonic gel, or epoxy to the outer pipe wall |
| Warranty | 2-year limited warranty |
Specifications transcribed from the manufacturer datasheet and subject to change. Confirm against the controlling document before specifying — Seztec will send it to you on request.
This instrument is specified into the following industries. Each page covers the specific measurement problems, the fluids involved, and what usually goes wrong.
Send us pipe size, pipe material, wall thickness, lining, fluid, and how much straight run you have. A Seztec application engineer will confirm the fit — or tell you it is the wrong instrument, which happens and which we would rather say before you buy.
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