Product Overview
The Telog Beluga is Badger Meter’s submerged ultrasonic area/velocity sensor for open-channel and partially-full-pipe flow — the choice where a radar can’t see the surface. Mounted in the channel, a 1 MHz twin-crystal Doppler element reads velocity by real-time spectral analysis of the velocity profile, an integrated differential-pressure module reads level, and the sensor computes flow by the area-velocity method internally — no flume, weir, or external controller. Because it is submerged, the Beluga keeps measuring when the pipe surcharges and floods, and the selectable Smart Velocity mode extends operation into very shallow flow (typically below 0.8 in. / 2 cm). Velocity holds to ±1% (±0.03 ft/s zero stability) bidirectionally over −6.56…19.68 ft/s, with the level module accurate to ±0.25% FS over 0…6.56 ft, field-replaceable, and built on a stainless-steel diaphragm. Housed in epoxy-potted high-impact PVC-C sealed to IP68 / NEMA 6P, it speaks RS-485 Modbus RTU / ASCII and pairs with a Ru-35 or RS-45 RTU — up to two sensors per logger — for cloud or SCADA delivery.
Key Features & Benefits
- Reads through surcharge — submerged in the stream, it keeps measuring when the pipe floods and a surface-reading sensor would lose the level
- Smart Velocity for shallow flow — a selectable mode estimates velocity and flow down to about 0.8 in. / 2 cm of depth, where many A/V sensors drop out
- Integrated level, replaceable — the built-in differential-pressure level module measures depth and swaps in the field without retiring the sensor
- Spectral velocity analysis — real-time digital spectral analysis of the velocity profile sharpens the reading and resolves slow and reversing flow
- Bidirectional — resolves forward and reverse flow, for tidally-influenced and backwater reaches
- Built for sanitary sewers — high-impact PVC-C with epoxy potting and an IP68 / NEMA 6P seal stands up to long submergence in raw wastewater
- Low-disturbance install — the side-mounted cable keeps the hydraulic profile clean across the sensor
- Two sensors per logger — pair to a Ru-35 or RS-45 to monitor up to two points from one telemetry unit
Specifications
- Measurement principle
- Submerged digital ultrasonic Doppler area/velocity — a 1 MHz twin-crystal sensor mounts in the channel and reads velocity by advanced digital spectral analysis of the velocity distribution; flow is computed inside the sensor by the area-velocity method (no flume or weir).
- Measures
- Open-channel level, velocity and flow (area-velocity), bidirectional — in both partially-full and fully surcharged pipes; an embedded sensor also logs water temperature (−40…176°F)
- Velocity accuracy
- ±1% (per hydraulic and installation conditions), ±0.03 ft/s zero stability, 0.003 ft/s resolution
- Velocity range
- −6.56…19.68 ft/s (−2…6 m/s), bidirectional
- Level measurement
- Integrated, field-replaceable differential-pressure level module with a stainless-steel diaphragm — ±0.25% FS over 0…6.56 ft, 0.04 in. (1 mm) resolution; 82 ft max. allowable level
- Output / interface
- RS-485 port, Modbus RTU or Modbus ASCII slave
- Enclosure / protection
- High-impact PVC-C shell with epoxy potting, IP68 / NEMA 6P; rated −4…122°F operating
- Mounting
- Mounts in the channel; the side-mounted cable saves space and reduces flow-hydraulic disturbance. Standard 32.8 ft cable (65.6 / 98.4 ft optional)
- Maintenance
- Field-replaceable pressure module; desiccant-protected atmospheric-reference air intake
- Pairs with
- Pairs with the Ru-35 or RS-45 RTU — up to two sensors per logger
Common Applications
- Partially-full and fully surcharged sewer flow where a surface sensor loses the level
- CSO/SSO and inflow-and-infiltration (I&I) monitoring in pipes that flood during wet weather
- Hydraulic-capacity modeling and collection-network model calibration
- Shallow-flow channels and low-depth conditions, via Smart Velocity
- Tidally-influenced and backwater reaches needing bidirectional flow
- Billing / custody-transfer flow on sewer interceptors
Design & Selection Considerations
- Log locally first — no power or signal required — every Telog device records to local memory and runs standalone indefinitely, so a site keeps recording even with no power and no network. Connectivity is optional at the start — a standalone logger can be promoted to live telemetry later without re-engineering.
- Recorder or cellular RTU? — battery recorders (HPR-32A, PR-32A, RG-32A) suit surveys and temporary studies you collect on a schedule; cellular RTUs (Ru-32, Ru-35, RS-45) transmit to the Telog RM cloud for permanent, real-time monitoring and alarming. Recorder for portable or temporary work; RTU for fixed sites you watch continuously.
- Match power and housing to the site — choose a multi-year lithium battery, solar, or AC power, and an IP68 submersible housing for vaults and sewers. The RS-45 runs continuous AC/solar duty; the Ru-35 is the submersible choice. Power and ingress rating decide where a site can go — spec them with the measurement.
- Open-channel: radar or submerged ultrasonic? — for sewers and partially-full pipes Telog uses the area-velocity method. The Raven-Eye 2 is non-contact radar (±0.5% velocity) — nothing touches the stream, so no fouling and no confined-space entry; the Beluga is submerged ultrasonic (±1%) that works even when the pipe surcharges, with integrated level and shallow-flow capability. Radar when you can see the surface and want the highest velocity accuracy; ultrasonic when it surcharges or radar can’t see in.
- Capture transients when they matter — for surge and water-hammer analysis specify the high-speed impulse variants — HPR-32iA, PR-32iA and the Ru-32iMA — which capture fast pressure transients a standard recorder would miss. Routine pressure logging and transient capture are different jobs — pick the impulse build when surge is the question.
- Plan the data path — cloud, SCADA, or both — Telog devices report to the Telog RM cloud (built on Esri ArcGIS) over their cellular link; the line-powered RTUs and gateways can also export to your SCADA over Modbus RTU, 4–20 mA or SDI-12, while the battery cellular recorders deliver through the cloud. Decide the destination — and confirm the outputs your specific device carries — up front.
To size & select the right Telog Beluga:
Use the input form to tell us what you need to measure and where, how the site is powered (battery, solar or AC), and how you want the data (the Telog RM cloud, your SCADA, or both) — and we’ll spec the recorder, RTU, sensor and outputs for your monitoring program.
Flow Meter Application Sheet ›Talk to an engineer directly — Scott Prater, Principal · 917-580-0878 · scott@pratertechnical.com
Specifications compiled by Prater Technical Partners from Badger Meter Telog product datasheets.