Ultrasonic Liquid Flow Meter with Thermal Energy/BTU Capability
Features LARGE LCD display, shows the Instantaneous Flow Rate, Total Flow, in user selectable units. One of the first Ultrasonic flow meters with a data logger. Both 24 VDC and universal AC power capability
Medium: Any acoustically conductive fluid with less than 5% air bubbles or solids
Pipe size: 2” to 48” Smallest pipe/tube:(1.125 OD with .05 wall with N or W Mounting)
Flow rate: Supports velocities up to 40 f/s or 12 m/s
Temperature: - 20 - 110 ℃
Transducer material: Aluminum and 304 SS
Cable length: 15’
Accuracy: ±1% from 0.15 to 40 f/s (0.05 to 12 m/s)
Resolution: 0.01 ft/s (0.00025 m/s)
Response time: 150 ms measuring cycle typical
Transducer Frequency: 1 MHz
Clamp-on transducers: encapsulated design IP68
Std Temp Spec for Blue Transmitters 194 F (90 C)
Std Temp Spec for BlackTransmitters 320 F (160 C)
Enclosure Grade: IP65
Display LCD Screen
Power Supply: Set up to use either 24VDC or a 86-240 VAC Universal Power Supply. Only one at a time. Consumes 500 mA max
Output: 4-20mA + 0-10K Hz + Standard ModBus RTU Communication protocol
Ultrasonic flow meter with data logger
Note: For 1 to 5 VDC output, add 250 Ohm resistor to 4 to 20 mA loop
HELPFUL QUICK NOTES: Menu 90 shows Signal Strength and Menu 00 shows main flow rate and total. Frequently, fine tuning may be had by invoking Menu 90 and making small movements of one of the transducers to get the highest signal. Numbers over 80% are considered very good. Also set menu 40, the Filter Coefficient, (We could call this the time constant or response time), with Menu 40 to 1 second to make the meter respond quickly. Then, put back to 4 seconds and save with Menu 26 and hit enter twice. Menu 45 is for entering a K-Factor, this would be handy if you KNOW the flow is 90 when it says 100. In this case a K-Factor of 0.9 would remedy it. (Ideally the distances and pipe thickness/material would be corrected but this is easier). Menu 70 and 71 allow LCD Display on time and contrast respectively
§3.1.6 Validating meter function. Entering a pipe outer diameter (Menu 11) of zero, results in the display to show the flow velocity: 1.2345678m/s (4.0504ft/s) [use down arrow to view], flow rate= will vary, and display “R”status on Menu 00. Inputing a set value in M44 will change the totalizer output. Use this function to test of the flow meter and network software without having to connect the transducers. If they are connected the flow rate may be + or -
Acoustic Coupling Grease Specifications:
Dow Corning Product Name: MOLYKOTE™ BR-2 Plus High Performance Grease This material is designed to remain in a gel like form to increase the acoustic coupling of the ultrasonic transducers to the pipe. This material works from -57 to 204 Degrees C which is above the specs of the transducers.
In a "pinch" one could use KY Jelly from the drug store but it is runny. The goal is to have a material that will not have bubbles in it and provides good sonic coupling. Air bubbles are the "enemy" of ultrasonic transducers. Using traditional Silicone sealant, such as that used for sealing windows, could also be used in an emergency but you MUST assure there are no air bubbles.
MAG Meter Complimentary Product line
Ultrasonic Meter Transducer Installation requirements: On this flow meter, as well as of all flow meters, it is CRITICAL that the pipe remains full at all times. This meter requires that the flow remain relatively consistent. Note 10 diameters clear of obstruction upstream and 5 diameters down.
Clamping system for pipes larger than 10" OD. Install by securing ends with clamps WITHOUT the transmitter and then stretch the nylon coated SS wire over the transmitter. BE SURE to grind a CLEAN area for the transmitter to conduct the sound AND use the Acoustic Coupling Grease on the transmitter/pipe interface.
Note how strap is used.
Sound speed of various materials:
Important notes on the use of Clamp On Meters of all brands:
While it is compelling to utilize these meters because of their ease of installation it is critical that the pipe material, thickness and ID are well known. Many times older pipes can have significant corrosion reducing the inner diameter to such a level that the sonic energy can not penetrate. Frequently banging on the pipe with a double jack can remedy and remove large "mushroom like" growths it can not remove long term built up scale that tends to absorb energy. Banging on some piping systems is NOT an option because it can break or cause a leak. We can not guarantee that a Clamp On Meter is ideal for the installation if the internal condition of the pipe is unknown. We will be happy to provide consultation to give ideas on how to measure flows in such conditions but can not be held to task should the internals of the pipe not be verifiable. Generally we will not refund the purchase price on a system where the pipe condition is difficult to obtain.