The CS-3300 series Ultrasonic Open-Channel Flow Meter is used together with a measuring weir or flume to measure the flow of water in an open channel. It is mainly used for sewage-treatment plants, the sewage-discharge outlets of enterprises and institutions, urban sewers, and irrigation channels in farmland water-conservancy projects.
It can directly display instantaneous flow and cumulative flow, with built-in EEPROM memory that retains data after a power failure. The measurement result is not affected by water quality, and multiple built-in algorithms support a wide range of standard weirs and flumes. Optional communication interfaces allow easy connection to DCS / cloud systems for remote monitoring.
The CS-3300 is available in three styles to suit different installation conditions: Integrated, Split, and Dual-Probe.
Besides this weir/flume-based meter, Sino-Inst also offers other open channel flow meters — including the non-contact radar flow meter and the no-weir ultrasonic Doppler flow meter — for open channel and river flow measurement.
1. Integrated (CS-3300-I)
The transmitter and ultrasonic probe are built into a single unit with no probe cable. Housing options: large ABS enclosure, or explosion-proof cast-aluminum enclosure. Best for compact installations where the display can sit at the measuring point.
2. Split (CS-3300-S)
The transmitter and probe are separate, connected by cable (standard 10 m, customizable up to 50 m). ABS enclosure. Best when the display needs to be located away from the measuring point.
3. Dual-Probe (CS-3300-D)
Uses two 100 kHz transducers in a transmit-and-receive arrangement — one probe transmits while the other receives — achieving a very small blind zone (as low as 0.08 m). Ideal for small spaces and short-range / small-blind-zone measurement.
| Parameter | Integrated | Split | Dual-Probe |
| Type | Integrated | Split | Dual-probe (one transmits, one receives) |
| Measuring principle / probe | Single ultrasonic probe; 100 kHz M48×2 for Parshall #1–9 (range 2 m, blind 13–15 cm); 64 kHz M48×2 for #10–25 (range 3 m, blind 30–40 cm) | Same as integrated | Dual 100 kHz transducers; blind zone as low as 0.08 m |
| Measuring range | 0.1 L/s – 99,999.99 m³/h (set by weir/flume type) | 0.1 L/s – 99,999.99 m³/h (set by weir/flume type) | Level 0.08 – 1 m |
| Cumulative flow | Max 4,290,000,000.00 m³ | Max 4,290,000,000.00 m³ | — |
| Max level range | 2 / 3 / 5 / 10 m (larger on request) | 2 / 3 / 5 / 10 m (larger on request) | 0.08 – 1 m |
| Level / measuring accuracy | 0.5% | 0.5% | 0.5% FS – 1% FS |
| Resolution | 3 mm or 0.1% (whichever is greater) | 3 mm or 0.1% (whichever is greater) | 1 mm |
| Flow accuracy | Parshall & triangular weir (GB): 1–5%; rectangular weir (GB): 10%; non-standard: 10–50% | Same as integrated | — |
| Display | LCD | LCD | LCD (12864, with / without backlight) |
| Analog output | 4-wire 4–20 mA / 510 Ω load | 4-wire 4–20 mA / 510 Ω load | 4–20 mA default (RS485 or relay optional) |
| Relay output | 2 optional, AC250V/5A or DC30V/5A, status configurable | 2 optional, AC250V/5A or DC30V/5A, status configurable | Relay output optional |
| Communication | RS485 / RS232 optional | RS485 / RS232 optional | RS485 optional (4G / NB-IoT on request) |
| Power supply | 220VAC ±15% 50Hz, or 24VDC (12VDC optional) | 220VAC ±15% 50Hz, or 24VDC (12VDC optional) | 12 – 26 VDC (avg. power 1.5 W) |
| Operating temperature | Meter -20 – +60 ℃; probe -20 – +80 ℃ | Meter -20 – +60 ℃; probe -20 – +80 ℃ | -20 – +60 ℃ |
| Process temperature | -20 – +80 ℃ | -20 – +80 ℃ | — |
| Protection grade | Meter IP65; probe IP68 | Meter IP65; probe IP68 | Transducer IP68; meter IP65 |
| Probe cable | None (integrated) | Standard 10 m (extendable to 50 m; after extension a larger-range probe may be required) | 20 m |
| Probe / sensor material | ABS standard; anti-corrosion material for corrosive media | ABS standard; anti-corrosion material for corrosive media | Sensor: POM |
| Transmitter / housing material | Transmitter ABS (PL) or aluminum (AL); large ABS or explosion-proof cast-aluminum enclosure | ABS enclosure | Main housing 304 stainless steel / ABS (316 customizable) |
| Mounting | Bracket / flange / top-thread hoisting | Bracket / flange / top-thread hoisting | Bracket mounting |
| No. | Flow min | Flow max | Channel ≥ W×H (mm) | h min (mm) | h max (mm) | n | C |
| 01# | 0.3 t/h | 19.4 t/h | 200×250 | 15 | 210 | 1.550 | 217 |
| 02# | 0.6 t/h | 47.5 t/h | 250×300 | 15 | 240 | 1.550 | 435 |
| 03# | 2.8 t/h | 115.6 t/h | 300×600 | 30 | 330 | 1.550 | 638 |
| 04# | 5.4 t/h | 399.6 t/h | 450×800 | 30 | 450 | 1.540 | 1372 |
| 05# | 9.0 t/h | 903.6 t/h | 600×1000 | 30 | 600 | 1.530 | 1927 |
| 06# | 12.6 t/h | 1440.0 t/h | 1000×1200 | 30 | 750 | 1.521 | 2444 |
| 07# | 16.2 t/h | 2268.0 t/h | 1200×1200 | 30 | 750 | 1.537 | 3737 |
| 08# | 45.0 t/h | 3060.0 t/h | 1400×1200 | 50 | 750 | 1.548 | 5051 |
Critical submergence — 01#–03# = 0.5; 04#–08# = 0.6.
| No. | Flow min | Flow max | Channel ≥ W×H (mm) | n / C |
| 01# | 0 | 20 | 275×220 | 2.5 / 5083 |
| 02# | 0 | 40 | 360×288 | 2.5 / 5083 |
| 03# | 0 | 80 | 475×380 | 2.5 / 5083 |
| 04# | 0 | 121 | 560×448 | 2.5 / 5083 |
| 05# | 0 | 182 | 660×528 | 2.5 / 5083 |
| 06# | 0 | 272 | 775×620 | 2.5 / 5083 |
| 07# | 0 | 395 | 900×720 | 2.5 / 5083 |
| 08# | 0 | 616 | 1075×860 | 2.5 / 5083 |
| No. | Flow min | Flow max | Channel ≥ W×H (mm) | n / C |
| 01# | 0.04 | 85 | 500×500 | 1.5 / 1280 |
| 02# | 0.05 | 195 | 650×650 | 1.5 / 1660 |
| 03# | 0.08 | 414 | 750×750 | 1.5 / 2406 |
| 04# | 0.10 | 803 | 850×850 | 1.5 / 3318 |
| 05# | 0.15 | 1662 | 1000×1000 | 1.5 / 4669 |
| 06# | 0.19 | 3332 | 1250×1250 | 1.5 / 5886 |
| 07# | 0.26 | 6504 | 1450×1450 | 1.5 / 8178 |
| 08# | 0.33 | 12643 | 1800×1800 | 1.5 / 10344 |
Triangular and rectangular weir grooves can be made on site according to the channel size; the Parshall flume can be produced on site by the customer or supplied as a set. Consult customer service for other weir/flume model parameters.
Build the complete model number by choosing one option from each position below, left to right. The style is the first position.
CS-3300 – ①Style – ②Range – ③Sensor housing – ④Thread – ⑤Mounting – ⑥Power/Ex – ⑦Relays – ⑧Output – ⑨Transmitter housing – ⑩Cable
| Position | Code | Options |
| ① Style | I / IE / S / D | I = Integrated, ABS; IE = Integrated, explosion-proof cast-aluminum; S = Split, ABS; D = Dual-probe (twin 100 kHz, blind zone ≥0.08 m) |
| ② Range | 01 / ~ / 10 | 01 = 1 m; ~ = 1–10 m; 10 = 10 m (Dual-probe is fixed at 0.08–1 m) |
| ③ Sensor housing | A / F / V | A = ABS; F = PTFE; V = PVDF |
| ④ Thread (mount size) | A / C / E | A = M48×2; C = M78×2; E = G2″ thread |
| ⑤ Mounting | A / B / C | A = bracket; B = flange; C = top-thread hoisting |
| ⑥ Power / Ex | see 6.1 | Common: DCSP = 12 VDC; DC = 24 VDC; AC = 220 VAC (all non-Ex). Full explosion-proof codes in table 6.1 below. |
| ⑦ Relays | R0 / R2 | R0 = none; R2 = 2 relays |
| ⑧ Output | MA / C2 / C4 … | MA = 4–20 mA; C2 = RS232; C4 = RS485; C2MA = 4–20mA+232; C4MA = 4–20mA+485 |
| ⑨ Transmitter housing | PL / AL | PL = ABS; AL = aluminum |
| ⑩ Cable length | 00 / 01–50 | 00 = none (integrated); 01 = 1 m … 50 = 50 m (split; 10 m standard) |
Example: CS-3300-S-10-A-A-A-AC-R2-C4MA-PL-10 = Split style, 10 m range, ABS sensor housing, M48×2 thread, bracket mounting, 220 VAC (non-Ex) power, 2 relays, 4–20 mA + RS485 output, ABS transmitter, 10 m cable.
Zhang Wei, possesses 20 years of experience as an automation instrumentation engineer, specializing in the research, design, installation, commissioning, and maintenance of automation instruments.
Face to various instrument communication protocols (such as Modbus, Profibus, etc.), with solid hardware circuit design and software programming skills (proficient in C language and PLC programming). Has extensive project experience; projects he has led and participated in have all achieved outstanding results, improving product accuracy, reducing costs, and increasing production efficiency.
Possesses excellent communication and coordination skills and a strong team spirit, enabling him to quickly respond to customer needs and provide high-quality automation instrumentation solutions.
