RBFM Fixed Clamp-on ultrasonic heat meters(BTU meter) employ the proven transit-time ultrasonic flow measurement technique combined with two PT 100 temperature sensors (or customer-supplied RTD sensors) for calculating total and instantaneous energy consumption. Flow measurement may be achieved via clamp-on, spool piece, or insertion-type sensors. Our microprocessor based, user friendly field programmable flow measurement technique creates no interruption of the process flow and allows for easy installation.
RBFM Fixed Clamp-on ultrasonic heat meter is available with a variety of features that make it adaptable to many different applications. Available transducer types include clamp-on, in-line, and insertion. Wall-mount, panel-mount, pipe-mounted and compact din-rail mounted display types are also offered. Additional available features include pulse, 0-20mA & 4-20mA outputs, RS-232 communication, user-selectable engineering units, and a data logger function. This variety of features, combined with its low cost, make the RB series an ideal choice for economical BTU monitoring in many applications involving chillers, radiators, and heat exchangers.
RBFM Series Clamp-on transit time heat flow meter utilizes two transducers that function as both ultrasonic transmitters and receivers. The transducers are clamped on the outside of a closed pipe at a specific distance from each other. The transducers can be mounted in V-method in which case the ultra sound transverses the pipe twice, or W-method in which case the ultra sound transverses the pipe four times, or in Z-method in which case the transducers are mounted on opposite sides of the pipe and the ultra sound transverses the pipe only once. The selection of mounting method depends on pipe and liquid characteristics. When the flow meter works, the two transducers transmits and receives ultrasonic signals amplified by multi beam which travels firstly downstream and then upstream (Figure 1). Because ultra sound travels faster downstream than upstream, there will be a difference of time of flight(△t). When the flow is still, the time difference(△t) is zero. Therefore, as long as we know the time of flight both downstream and upstream, we can work out the time difference, and then the flow velocity (V) and flow volume (Q) via the following formula.
V= K*D* △t
V: Liquid velocity
K: Constant
D: Distance between the two transducers
△t: Difference in time of flight
RBFM Fixed Clamp-on ultrasonic heat meters(BTU meter) Features:
RBFM Fixed Clamp-on ultrasonic heat meters(BTU Meter) Specifications
Measuring Principle |
Transit time difference |
Mounting |
wall mounting, panel, local |
Transducer type |
clamp-on, spool piece, or insertion |
Display |
LCD with backlight, 2 x 20 characters 1-line, non-backlit 7 digit LCD (ILD version) Displays energy rate, total consumption, temperature, instantaneous flow rate, accumulated flow rate, velocity, time |
Keypad |
4 x 4 tactile-feedback membrane keypad |
Pipe Size |
25-6000mm |
Pipe Material |
Carbon Steel, Stainless Steel, Ductile Iron Copper, PVC, Aluminum, Asbestos Fiberglass, etc. |
Output Signals |
4-20mA , Impedance 0-1kΩ, pulse, relays, Isolated OCT for alarms (on/off with buzzer) |
Inputs |
Two RTD channels, and additional inputs |
RBFM Ultrasonic Flow/Heat Meter(BTU meter) Model Selection
RBFM |
X |
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X |
X |
DNxx |
X |
X |
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X |
X |
X |
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Instrument Type |
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F |
Ultrasonic Flowmeter |
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H |
Ultrasonic Heat meter |
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Power supply |
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A |
220VAC |
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D |
24VDC |
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B |
Battery |
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Flow/Heat meter Type |
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F |
Fixed type |
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H |
Handheld type |
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F |
Flanged type |
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B |
Battery type |
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Transducer Type |
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SN |
S type(pipe size: 15-100mm, temp.: -30 to 90℃) |
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SH |
S type(pipe size: 15-100mm, temp.: -40 to 160℃) |
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SPMN |
S type with mounting frame only for Handheld (pipe size: 15-100mm, temp.: -40 to 90℃) |
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SPMH |
S type with mounting frame only for Handheld(pipe size: 15-100mm, temp.: -40 to 160℃) |
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MN |
M Type(pipe size: 50-700mm, temp.: -30 to 90℃)) |
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MH |
M Type(pipe size: 50-700mm, temp.: -40 to 160℃)) |
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MPMN |
M type with mounting frame only for Handheld (pipe size: 50-300mm, temp.: -40 to 90℃) |
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MPMH |
M type with mounting frame only for Handheld (pipe size: 50-300mm, temp.: -40 to 160℃) |
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RB-1 |
extended the mounting frame, for pipe:DN300-700mm, temp.: -40 to 90℃ |
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RBH |
extended the mounting frame, for pipe:DN300-700mm, temp.: -40 to 90℃ |
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LN |
L type(pipe size: 300-6000mm, temp.: -30 to 90℃) |
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LH |
L type(pipe size: 300-6000mm, temp.: -40 to 160℃) |
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I |
Insertion Type |
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IE |
Extended type |
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F |
Flanged type |
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Pt100 |
Temperature sensor |
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DNxx |
Pipe size |
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Pipe material |
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C |
Carbon Steel |
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SS |
Stainless Steel |
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CI |
cast iron |
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F |
Fibreglass |
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P |
PVC |
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C |
cement pipe |
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X |
Others, clarify |
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X |
Pressure(MPa) |
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Output |
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N |
NO |
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A |
4-20mA |
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P |
Pulse |
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R |
Relay |
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2 |
RS232 |
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4 |
RS485 |
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5 |
Datalogger |
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Input |
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N |
NO |
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1 |
1*4-20mA |
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2 |
2*4-20mA |
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3 |
3*4-20mA |
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Cable length |
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X |
meter |
Catalog - Clamp-on Ultrasonic heat meter
Manual - Fixed Ultrasonic Heat meter
Other files - Clamp-on Ultrasonic heat meter
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