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『Contactless Flow Meter: Non-Contact Radar and Ultrasonic Water Line Level Senses』Related information(v cone flow meter|rotary gas meter|gallon meter|gear meter|metal tube rotameter|glass tube rotameter|nutating disk meter|transit time ultrasonic flow meter|wedge flow meter|pd meters|hydraulic flow meter|ultrasonic water flow meter|water flow meter|air flow meter|magnetic water flow meter|oxygen flow meter|gas flow meter|argon flow meter|air velocity meter|gasoline flow meter|fuel flow meter|ultrasonic water meter|digital water meter|nitrogen flow meter|solid flow meter|Oxygen tank flow meter|digital water flow meter|diesel fuel flow meter|steam flow meter|02 flow meter|compressed air flow meter|oil flow meter|liquid flow meter)
Contactless Flow Meter: Non-Contact Radar and Ultrasonic Water Line Level Senses
Quick Answer: Non-contact radar and ultrasonic sensors measure water level and flow without touching the liquid. They work well for wastewater channels, open flumes, pump station wet wells, and desalination plant intake lines. Silver Instruments supplies 4-20 mA HART radar and ultrasonic level meters with IP68 housings for these jobs.
In practice, most engineers skip mechanical floats and pressure transmitters on dirty water lines. Contactless sensors survive better because no part meets the water, sludge, or corrosive brine. We have seen this on customer sites many times across Southeast Asia, Oceania, and the Middle East.
Why Non-Contact Radar and Ultrasonic Sensors Fit Water Line Measurement
A contactless flow meter or level sensor sends a signal through air and reads the echo. Radar uses microwaves. Ultrasonic uses high frequency sound. Both work through dust, humidity, and temperature swings. But radar handles foam, vapour, and light turbulence better than ultrasonic. Ultrasonic costs less and works fine on clean water tanks, sumps, and level applications without heavy foam.
Water lines are often open channels, not full pipes. A magmeter or Coriolis flowmeter will not help there. You need a level sensor that converts head or level into flow rate. A radar sensor mounted above a flume or weir outputs level and a local RTU or flow computer calculates flow. Silver Instruments offers radar sensors with built-in flow conversion for common flume types.
Radar Level Sensors for Open Channels and Partially Filled Pipes
Radar level meters use 26 GHz or 80 GHz signals. The 26 GHz type works for ranges up to 30 m. Accuracy is usually plus or minus 2 mm or plus or minus 5 mm depending on antenna. The 80 GHz type has a narrower beam angle, so it avoids sidewall echoes in narrow channels or tanks with internals. We recommend 80 GHz for pump station wet wells with ladders, pipes, and brackets.
Typical output is 4-20 mA HART with optional RS485 Modbus. Power is 24 V DC. Housing is aluminium or PTFE coated for marine environments. Process connection can be a bracket, flange, or G1 thread. A desalination plant in Saudi Arabia asked us for radar level sensors on filtered seawater intake channels. They used a 0.5 m Parshall flume, DN300 intake piping, and 4-20 mA HART output to their SCADA. The sensors have run for two years without fouling.
Because radar does not care about air temperature above the water surface, it beats ultrasonic on outdoor sites with strong sun and high condensation. In northern Australia, a wastewater utility replaced ultrasonic sensors on six open channels after fog caused false echoes in the wet season. Radar solved that issue.
Ultrasonic Level Sensors for Clean Water Tanks and Dosing Skids
Ultrasonic level meters transmit pulses at 30 to 50 kHz. They work best on clean water, filtered water, and low foam chemicals. Range goes up to 15 m on a 2 inch transducer. Accuracy is typically 0.2 percent of full scale or plus or minus 5 mm. The dead zone matters. A 0.3 m dead zone means you cannot measure within 0.3 m of the sensor face. Install the sensor high enough.
Output options include 4-20 mA, 0-10 V, and RS485 Modbus. Some models include relay outputs for high and low level alarms. A food grade wat
Typical Installations and Signals to Specify
Engineers often ask what signal is best. For new installations, 4-20 mA HART is the safe choice. It carries level and diagnostic data over two wires. If the site uses Modbus, choose RS485. If the distance is over 100 m or the plant has no spare control room cable, a wireless LoRa or NB-IoT module can also work. Silver Instruments can integrate these options.
For open channel flow, send the flume or weir type. Common flumes include Parshall, Palmer-Bowlus, and V-notch weir. We need the maximum flow rate and channel width to recommend the right model. For tank level, send the tank height, material, temperature range, and whether there is agitation or foam. In many cases, a 26 GHz radar sensor with a PTFE antenna is the most reliable choice for caustic or acid vapour environments.
A chemical plant in Vietnam purchased five radar level sensors for sodium hydroxide day tanks. The tanks had vapour and occasional splashing. The 80 GHz radar models performed better than ultrasonic during a 3 month trial. The plant then standardized on radar for all corrosive chemical day tanks.
FAQ
Question: Can a contactless flow meter measure total volumetric flow in open channels?
Answer: Yes. A radar or ultrasonic level sensor measures water level. The flow computer or RTU converts level to flow using a known flume or weir curve. Silver Instruments supplies sensors with preloaded curves for common flumes.
Question: Which is better for wastewater, radar or ultrasonic?
Answer: Radar works better on wastewater with foam, fat, sludge, and vapour. Ultrasonic can fail when foam absorbs the sound. Use radar for pump station wet wells and open channels. Use ultrasonic for clean water tanks and chemical storage.
Question: What is the minimum pipe size or channel width for these sensors?
Answer: There is no strict minimum pipe size because these sensors usually mount above open channels or tanks. For flumes, the channel width can be as small as 75 mm with a small Parshall flume. The sensor beam angle must be narrow enough to avoid the walls. An 80 GHz radar with a 4 degree beam angle handles narrow channels well.
Question: Do these sensors work in ATEX Zone 1 hazardous areas?
Answer: Yes. Several radar and ultrasonic models have ATEX, IECEx, or NEC certifications for Zone 1 and Zone 2. Specify the gas group and temperature class when you order. Silver Instruments can supply certified units for oil and gas water knockout drums and chemical storage.
Question: What should I send for a fast quote?
Answer: Send us the water line size, level range, channel type if any, output signal needed, power supply, and hazardous area classification. Also tell us if the site is coastal or has heavy rain. We will recommend the right sensor and quote within one working day.
Contact Silver Automation Instruments by phone at +86-25-68650347, Whatsapp at +86-25-52155837, or WeChat at +86 15365082610. Send us your water line level range, pipe size, temperature, and output signal for a specific quote.