Hot and Chilled Water
Clamp-on monitoring of circulating-water systems without cutting into established heating or cooling pipework.
Ultrasonic Meter
The Cadillac® Ultrasonic Flow Meters are rate and totalizing meters which are capable of measuring liquids, of all types, non-intrusively.
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The Cadillac® Ultrasonic Flow Meters are rate and totalizing meters which are capable of measuring liquids, of all types, non-intrusively. Due to its universal (one size fits all) design and ease of installation, it is particularly suitable for Hot and Chilled water measurements.
Integrating Digital Processing (DSP) with advanced correlation detection methods, the flow meter features exceptional performance and flexibility. Combining ease of installation (non-intrusive pipe clamp-on), high accuracy, no moving parts, reliability, low maintenance, rangeability and no pressure drop, Cadillac® Ultrasonic flow meters have become the fastest growing liquid flow technology in the world today.
The Cadillac® Meter Energy Calculator is designed to measure energy consumed in hot water heating and chilled water cooling systems. Supplied with temperature probes, the calculator integrates the Cadillac® Ultrasonic Flow Meters to provide flexibility to meet all application needs. Modes of operation include: Heating, Cooling, Heating/Cooling and Charge/Discharge.
Technical Product Guide
Cadillac CU-T Ultrasonic Flow Meter
Explore the CU-T clamp-on ultrasonic flow meter, including its Transit Time operating principle, published performance, system outputs, installation requirements, transducer mounting methods, dimensions and model-selection guidance.
Product Overview
Non-Intrusive Clamp-On Liquid Flow Measurement
The Cadillac CU-T Ultrasonic Flow Meter is a rate-and-totalizing meter designed to measure liquid flow without cutting into the process pipe. Its matched ultrasonic transducers attach to the outside of the pipe, allowing the system to measure flow without placing a sensor, obstruction or moving component inside the liquid stream.
This clamp-on arrangement is particularly useful for retrofit, submetering and monitoring projects where shutting down the system or installing an intrusive meter spool would be difficult. Because the meter does not interrupt the flow path, it introduces no meter-related pressure drop and permits transducer service without opening the process pipe.
Clamp-On Installation
Matched transducers mount externally using sonic coupling compound and the appropriate rack, strap or clamp assembly.
No Pressure Drop
No meter body, rotor or other obstruction is inserted into the liquid stream.
Broad Pipe Coverage
Published transducer arrangements cover pipe diameters from 1/2 inch through 200 inches.
System Connectivity
Published options include 4–20 mA, pulse or relay output and RS485 Modbus RTU communications.
Applications
Where the CU-T Ultrasonic Flow Meter Is Used
The CU-T is suited to full-pipe liquid-flow applications where the process conditions permit reliable Transit Time ultrasonic measurement. Its external transducers make the meter especially practical for existing systems where intrusive installation, process shutdown or additional pressure loss would be undesirable.
Water and Wastewater Systems
Flow-rate and totalization measurement in full pipes where the liquid, aeration and suspended-solids conditions remain suitable for Transit Time technology.
Energy-Management Systems
A flow-data source for building management systems, distributed control systems and district-wide monitoring platforms.
Submetering and Cost Allocation
Totalized flow data for customer billing support, departmental allocation and campus-wide utility-management systems.
Process Monitoring
Remote indication, totalization and operational trending from plant or central control rooms.
System Optimization
Flow information for evaluating thermal-system performance, operating conditions and efficiency improvements.
Operating Principle
How Transit Time Ultrasonic Measurement Works
The CU-T uses a matched pair of piezoelectric ultrasonic transducers attached to the outside of the process pipe. Sonic coupling compound helps transfer ultrasonic energy from each transducer through the pipe wall and into the moving liquid.
Each transducer alternately sends and receives ultrasonic pulses. The meter compares the time required for a pulse to travel downstream with the time required to travel upstream. The difference between these transit times changes in proportion to the liquid’s velocity.
Transmit the Signal
Ultrasonic energy travels between the upstream and downstream clamp-on transducers.
Compare Travel Times
Liquid movement creates a measurable difference between upstream and downstream transit times.
Calculate Velocity
Digital signal processing converts the measured phase and transit-time difference into liquid velocity.
Determine Flow Rate
Velocity is multiplied by the programmed internal cross-sectional area of the pipe to calculate volumetric flow.
Pipe Data Is Part of the Measurement
The pipe’s outside diameter, wall thickness, material and lining affect the ultrasonic path and calculated internal area. Accurate project data must be entered before the transducers are positioned and the meter is commissioned.
CU-T Technology Scope
Some older Cadillac webpage copy also describes Doppler ultrasonic measurement. The supplied CU-T product literature identifies this model as a Digital Correlation Transit Time meter. Doppler capability should not be assumed for the CU-T.
Performance and Specifications
Published CU-T Operating Data
The CU-T combines Digital Correlation Transit Time measurement with remote electronics, a backlit display and integral keypad programming. Actual performance depends on the liquid, pipe condition, programmed pipe data, flow profile, transducer placement and available straight run.
| Parameter | Published CU-T Information |
|---|---|
| Measurement technology | Digital Correlation Transit Time |
| Meter arrangement | Remote electronics with one matched pair of clamp-on transducers and transducer cables |
| Displayed information | Instantaneous flow, totalized flow, velocity and operational status |
| Display | Four-line, 16-character backlit LCD |
| Programming | Integral keypad |
| Published flow range | 0 to +40.0 ft/s (0 to +12.0 m/s), with bi-directional flow capability stated |
| Published accuracy | Typically ±1.0% of reading at published rates below 1.65 ft/s; accuracy also depends on the flow profile |
| Additional brochure statement | ±0.5% of velocity or ±0.05 ft/s for Transit Time flow |
| Repeatability | 0.2% of reading |
| Published turndown | Minimum 50:1 |
| Transducer temperature | −4°F to +250°F (−20°C to +121°C) |
| Transmitter temperature | −4°F to +130°F (−20°C to +60°C) |
| Standard housing | NEMA 4X (IP65), ABS plastic |
Electronics and Integration
Outputs, Communications and Power Options
The CU-T remote electronics provide local flow information while supporting connection to building-management, process-control and data-acquisition systems. The required output combination and power supply must be selected as part of the meter configuration.
4–20 mA Output
An optically isolated analog output is available for transmitting a scaled flow signal to compatible monitoring and control equipment.
Pulse or Relay Output
A digital output can be configured for pulse or relay operation, depending on the selected output arrangement and connected system.
RS485 Modbus RTU
The published communications option allows CU-T data to be integrated with compatible BMS, DCS and remote monitoring platforms.
| Output Code | Published Output Arrangement |
|---|---|
| A | 4–20 mA output or digital output using pulse or relay |
| B | 4–20 mA output plus digital output using pulse or relay |
| C | 4–20 mA output, digital pulse or relay output, and RS485 Modbus RTU |
Published Power Options
- 90–132 Vac, 50/60 Hz — published standard
- 190–250 Vac, 50/60 Hz
- 20–30 Vdc
Integration Information to Confirm
Define the required flow units, analog scaling, pulse value, relay function, Modbus addressing and available site power before ordering. Portable configurations are listed separately in the legacy model code and do not include the digital output.
Installation
Selecting the Transducer Location
Installation location is critical because the process pipe acts as both the flow containment and the measurement section. The CU-T requires a representative flow profile, reliable ultrasonic transmission and a section of pipe that remains completely full.
The published straight-run guidance is a baseline. Pumps, control valves, double bends and other major disturbances may require substantially more upstream distance.
| Installation Factor | Published Guidance |
|---|---|
| Full-pipe condition | Choose a pipe section that remains completely full under every expected operating condition. |
| Normal straight run | Provide at least 10 pipe diameters upstream and 5 pipe diameters downstream. |
| Major disturbances | After a pump, control valve or double pipe bend, as much as 30 upstream pipe diameters may be required. |
| Horizontal pipe orientation | Mount the transducers at approximately the 3 o’clock and/or 9 o’clock position. |
| Pipe temperature | Confirm that the pipe-skin temperature remains within the selected transducer’s published temperature range. |
| Pipe condition | Prefer a location where the inside and outside surfaces are free from excessive scale, corrosion, rust or debris. |
| Service access | Allow sufficient room for the mounting assembly, transducer spacing, cable routing, programming and future service. |
Why Use the Side of a Horizontal Pipe?
Mounting at the side helps prevent sediment collecting along the bottom of the pipe or bubbles and air pockets gathering at the top from interfering with the ultrasonic signal path.
Pipe Surface Preparation
The mounting area must provide dependable acoustic contact. Remove loose rust, heavy paint buildup, debris and other surface contamination before applying the specified sonic coupling compound.
Baseline Straight-Run Arrangement
10D
Minimum upstream straight run
CU-T Transducer Location
5D
Minimum downstream straight run
“D” represents the internal pipe diameter. Disturbance-specific requirements may be greater than this baseline.
Transducer Installation
W, V and Z Transit Time Mounting Methods
Transit Time transducers can be installed using W, V or Z mounting geometry. The published literature associates each method with a typical range of pipe diameters, but final selection depends on the pipe, liquid, signal strength and available acoustic path.
Transducer spacing is calculated from the pipe’s outside diameter, wall thickness, material, lining and liquid information entered into the meter. The transducers should not be positioned using nominal pipe size alone.
W Mounting
Published Typical Range: 3/4–4 Inches
A multiple-traverse signal path commonly used on smaller pipes to increase the ultrasonic travel distance and measurement resolution.
V Mounting
Published Typical Range: 4–16 Inches
Both transducers mount on the same side of the pipe, with the ultrasonic signal reflecting from the opposite pipe wall.
Z Mounting
Published Typical Range: 16 Inches and Larger
The transducers mount on opposite sides of the pipe to create a direct ultrasonic path through the moving liquid.
Published R1 Rack Arrangement
- Rack drawing: 17.75 inches long and 2.00 inches high
- R1 transducers: published for 1.5–40-inch pipe
- R1 rack mounting assembly: identified for 1.5–10-inch line sizes
Do Not Select by Diameter Alone
The pipe ranges above are general guidance from the legacy brochure. Confirm the transducer type, mounting hardware, calculated spacing and W, V or Z arrangement for the actual pipe and liquid before installation.
Recommended Installation Sequence
- Verify the pipe remains full and the location satisfies the required straight run.
- Confirm the pipe outside diameter, wall thickness, material, liner and liquid information.
- Prepare the external pipe surface and apply the specified sonic coupling compound.
- Install the selected transducers at the calculated spacing and orientation.
- Route the signal cables away from avoidable electrical noise, heat and mechanical damage.
- Program the meter, verify signal quality and compare the indicated flow with expected system operation.
Dimensions
Electronics Enclosure and Rack Dimensions
The legacy product material contains two electronics-enclosure drawings and a separate R1 transducer-rack drawing. These dimensions are useful for preliminary space planning, but the exact enclosure and mounting arrangement must be confirmed on the project submittal before drilling, fabrication or installation.
| Component | Published Drawing Dimensions |
|---|---|
| CU-T electronics enclosure | 193 mm wide and 76.5 mm deep. The drawing shows a 261 mm overall height, with additional vertical reference dimensions of 241 mm and 239 mm. The upper mounting reference is shown as 66 mm. |
| Alternate enclosure drawing | 5.12 inches wide and 7.76 inches overall height. Additional height references are shown as 6.69 inches and 5.51 inches. Mounting-hole spacing is 2.76 inches, with a 0.35-inch mounting-plate reference. |
| R1 rack assembly | 17.75 inches long and 2.00 inches high. The legacy drawing identifies the rack assembly for mounting on 1.5–10-inch line sizes. |
Front Access
Preserve clear access to the display and keypad for programming, commissioning and operational checks.
Cable Clearance
Allow adequate space beneath the enclosure for cable glands, wiring access and the required cable bend radius.
Transducer Access
Keep the rack, retaining straps and both transducers accessible for adjustment, recoupling and future service.
Model Selection
CU-T Model-Code Guidance
The historical brochure uses one combined model-code chart for the CU-T flow meter and CU-E energy meter. The information below isolates the choices relevant to the CU-T Transit Time flow-meter configuration.
The model code should be treated as selection guidance rather than a current ordering guarantee. Confirm option availability, compatibility and the complete configured model number with Cadillac Meter before release.
| Code | Published Meaning |
|---|---|
| CU-T | Cadillac Ultrasonic Flow Meter using Digital Correlation Transit Time |
| Power A | 90–132 Vac, 50/60 Hz — published standard |
| Power B | 190–250 Vac, 50/60 Hz |
| Power C | 20–30 Vdc |
| Output A | 4–20 mA output or digital pulse/relay output |
| Output B | 4–20 mA output plus digital pulse/relay output |
| Output C | 4–20 mA output, digital pulse/relay output and RS485 Modbus RTU |
| Option A | Standard configuration with no additional option |
| Configuration D | Dedicated configuration |
| Configuration P | Portable configuration; the legacy chart states that digital output is not available |
Cable and Transducer Assembly Codes
| Code | Published Meaning |
|---|---|
| Cable 06 | 6-metre transducer cable — published standard |
| Cable 10 / 15 / 20 / 30 | 10-, 15-, 20- or 30-metre transducer cable |
| R1 | Transducers for 1.5–40-inch pipe, with rack assembly identified for mounting on 1.5–10-inch pipe |
| R2 | Transducers and rack assembly for 0.5–2.0-inch pipe |
| R3 | Transducers only for 40–200-inch pipe |
| R4 | Transducers and round circular clamp for 0.5–2.0-inch pipe; the pipe size must be specified |
| R5 | Transducers only, without a mounting-rack assembly |
Selection Checklist
Information Required for CU-T Selection
Successful ultrasonic measurement depends on more than nominal pipe size. Provide the actual process, pipe, installation and integration information so Cadillac Meter can review signal suitability, mounting geometry and the correct CU-T configuration.
Liquid Information
- Liquid name and composition
- Cleanliness and suspended solids
- Aeration or entrained bubbles
Pipe Information
- Pipe material and nominal size
- Actual outside diameter
- Wall thickness or schedule
- Liner material and thickness
Operating Conditions
- Minimum, normal and maximum flow
- Expected flow direction
- Liquid and pipe-skin temperature
- Required measurement accuracy
Installation Conditions
- Available upstream and downstream run
- Nearby pumps, valves and pipe bends
- Full-pipe confirmation
- Pipe surface condition and access
Electronics
- Available supply voltage
- Dedicated or portable configuration
- Required transducer cable length
- General or special area classification
System Integration
- 4–20 mA scaling
- Pulse or relay requirements
- RS485 Modbus RTU requirements
- Flow units and totalization units
Review the CU-T Against Your Actual Application
Use the complete technical guide for detailed selection and installation guidance, or contact Cadillac Meter for application review and a project-specific quotation.