The Armstrong AUP Ultrasonic Portable Flowmeter hand-held unit is a highly compact and powerful flow and BTU meter. Utilizing proprietary technologies such as ultrasonic signal processing, signal quality tracking, self-adaptation, and high-density electronic design, the device reliably and accurately measures liquid flow, temperature, and thermal energy from the outside of a pipe. The meter is completely portable and utilizes clamp-on sensors to perform non-invasive measurements, eliminating pipeline disturbances, pressure losses, and process interruptions.

Equipped with a rechargeable battery that allows for over 8 hours of continuous operation, the AUP also features a built-in data logger with up to 4GB of memory. This provides immense flexibility for data-logging and analysis. The Armstrong AUP is an ideal choice for flow surveys, meter verification, pump checking, HVAC and energy balancing, energy auditing, and facility management.

Measurement Principle

Armstrong ultrasonic portable flow and energy meters are based on the transit-time measurement principle. The system utilizes a pair of sensors that function as both ultrasonic transmitters and receivers. The sensors are clamped on the outside of a closed pipe at a specific distance from each other.

The flowmeter operates by alternately transmitting and receiving a frequency-modulated burst of sound energy between the two sensors and measuring the transit time it takes for sound to travel between them. The difference in the transit time is directly related to the velocity of the liquid in the pipe. The flowrate is then calculated based on the transit-time difference, the geometry of the pipe, and fluid dynamics formulas.

Thermal Energy (BTU) Measurement

The AUP flowmeter can be equipped with two temperature measurement channels to accommodate two PT100 RTD sensors directly. By combining the flow rate and temperature differential information, the AUP calculates the thermal energy (or caloric) consumed.

Features and Benefits

• Accurately measures energy and flow using non-intrusive technology.
• Capability of measuring bi-directional flow and energy.
• Ease of use and fast installation with no special skills or tools required.
• Able to measure on a very wide pipe size range, from 3/4" up to 120".
• Ergonomic design, allowing the main unit to be held and operated with one hand.
• Signal quality tracking and self-adaptation for robust performance.
• Suitable for pure liquids and liquids with some particles (fewer than 1% suspended particles < 75um). No dependency on conductivity.
• Suitable for all commonly used pipe materials (all metals, most plastics, some lined pipes).
• Rechargeable battery for up to 8 hours of operation.
• Built-in large data logger (up to 4GB space / >150,000 measured values).
• PC software for data download and real-time data acquisition via RS232/USB.

Typical Applications

• Energy consumption supervision and water conservation management.
• Cooling systems and air conditioning/glycol solutions.
• Water, including hot water, chilled water, city water, sea water, and process water.
• Sewage and drainage water with small particle quantity.
• Oil, including crude oil, lubricating oil, diesel oil, and fuel oil.
• Chemicals, including alcohol, acids, and solvents.
• Power plants (nuclear, thermal & hydropower) heat energy and boiler feed water.
• Pipeline leak detection, inspection, tracking, and collection.

Transducer Options

There are several types of transducers available for different pipe sizes. AS, AM, and AL transducers feature a mounting rail for easy installation.

Transducer Model	Pipe Size Range	Temperature Range
AS (Small)	3/4" to 3"	32°F to 312°F (0°C to 150°C)
AM (Medium)	3" to 28"	32°F to 312°F (0°C to 150°C)
AL (Large)	28" to 120"	32°F to 312°F (0°C to 150°C)

Installation Methods

The site of the transducer installation is critical for accuracy. An optimal location is a long, straight pipeline filled completely with the liquid to be measured.

Straight Pipe Run Recommendations

To achieve good accuracy, it is recommended to have a 15D straight-pipe run: upstream 10D and downstream 5D (where D is pipe diameter). If there is a pump upstream, a 30D straight pipe run is recommended.

Pipe Must Be Full

Make sure that the pipe is completely filled with liquid. It is impossible to take an accurate measurement if there are air bubbles. For horizontal pipes, install the transducers on the side of the pipe (e.g., at 90 and 270 degrees), not on the top or bottom, to avoid gas bubbles and sediment.

Reflect-Method (V-Method)

The Reflect-Method installation is the most widely used method for measurements in pipes ranging from 1" to 12". This method doubles the sound path, ensuring an accurate measurement for small and medium pipes.

Direct-Method (Z-Method)

The Direct-Method is commonly used for large pipe diameters between 12" and 120". The two sensors are installed on opposite sides of the pipe. Signal strength is increased with this method because the sound crosses the pipe only once.

W-Method

The W-method may be used on plastic pipes with diameters between 3/4" and 4", as an alternative to the Reflect-Method. The sound transverses the pipe four times.

PC Software and Data Logging

The AUP features a built-in data logger capable of storing up to 4GB of memory (e.g., 314,572 lines for 4 basic items, or 61,923 lines for all 16 diagnostic items).

ArmManager / RW Software is a Windows-based PC software aimed to facilitate the use of the AUP. It allows users to download data from the data logger directly to a computer via a USB/RS232 connection. The software can format the downloaded raw data into standard formats (like .csv for Excel) and allows for real-time data acquisition displayed on a graphical interface.