GE AT868 Panametrics Liquid Flow Ultrasonic Transmitter

Applications

The AquaTrans AT868 Liquid Flow Transmitter is a complete ultrasonic flow metering system for measuring the following liquids:

- Drinking water

- Wastewater

- Sewage

- Discharge water

- Treated water

- Cooling and heating water

- Other liquids

Features

- Economical, non-intrusive flow measurement

- Simple setup and installation

- Suitable for a wide range of pipe sizes and materials

- Suitable for lined pipes

- Dual channel/dual path versions available

- Velocity, volume and totalized flow

- Built-in keypad for field programming

Liquid Flow Ultrasonic Transmitter

The AquaTrans AT868 Liquid Flow Ultrasonic Transmitter combines state-of-the-art flow measurement capabilities with a low-cost transmitter package that can be mounted directly at the process measurement point.

It can be installed directly at the process measurement point. It is designed for water and wastewater applications in full pipelines.

The all-digital AquaTrans AT868 has no moving parts and requires minimal maintenance.

The on-board microprocessor utilizes patented Correlation Transit-Time™ technology for long-term drift-free operation. Automatically adjusts to changing fluid characteristics and dynamically configurable operating software simplifies programming.

Transit-Time Flow

Measurement Technology

Transit-Time technology uses a pair of transducers, each of which sends and receives a coded ultrasonic signal through the fluid.

As the fluid flows, the signal transmission time in the downstream direction is shorter than in the upstream direction; the difference in transmission time is proportional to the flow rate.

The AquaTrans AT868 measures this time difference and uses programmed pipe parameters to determine flow rate and direction.

Wet or clamp-on sensors

Ultrasonic flow sensors are classified as wetted or non-wetted (clamp-on). Clamp-on sensors are clamped to the outside of the pipe and do not come into contact with the process fluid.

Wetted sensors are mounted inside the pipe or flow meter and come into direct contact with the process fluid.

Clamp-on sensors offer the greatest convenience and flexibility, as well as low installation costs, compared to traditional flow metering technologies.

When properly installed, wetted sensors provide the highest accuracy (better than 1% of reading) in most applications.

Dual Channel Models

An optional second channel measures flow in two pipes or the average of two paths on the same pipe for improved accuracy.

AT868

Specification

Operation and Performance

Fluid Types

Acoustically conductive fluids, including most clean fluids and many fluids with entrained solids or bubbles. Maximum void fraction depends on transducer, interrogation carrier frequency, path length, and duct configuration.

Pipe Size

- Clamp-on transducers: 0.5 to 300 inches (12.7 mm to 7.6 m) and larger

- Wetted sensors: 1“ to 200” (25.4 mm to 5 m) and larger

Pipe wall thickness

3 inches (76.2 mm) maximum

Pipe Materials

All metals and most plastics. Consult GE for concrete, composite, highly corrosive, or lined pipe.

Flow Accuracy (Flow Rate)

0.5% of reading (achievable through process calibration)

Typical clamp-on flow accuracy (velocity)

- Pipe ID > 6 inches (150 mm): ±1% to 2% of reading

- Pipe ID <6 inches (150 mm): ±2% to 5% of reading

Typical wetted flow accuracy (velocity) ±1% of reading

Accuracy depends on pipe size and installation, and whether the measurement is single or dual path.