Isodaq Technology is now part of Hydro International.

Closed-pipe flow measurement options

 We offer two alternative types of solution for closed-pipe flow measurement based on -

•   ISODAQ telemetry logger (RTU) linked to a measurement sensor, or
•   Range of flow meters with integral data loggers, to which an ISODAQ  telemetry logger may be fitted

 ISODAQ telemetry logger (RTU) solutions for closed or partially-filled pipe flow meters

The following table is a guide to the selection of the type of flow meters and methods we recommend.  The preferred combination of ISODAQ and sensor type will depend on several factors including the type of site and application:-

Channel type Method Sensor models Isodaq RTU model
Culvert/part-filled pipe Ultrasonic doppler Mace Meters Hawk XT 
Culvert/part-filled pipe U/s Cross-correlation Nivus Hawk XT 
Large closed pipe Ultrasonic transit-time Quantum AquaSound Hawk XT, Frog R2/R3 
Small closed pipe Electromagnetic Siemens Hawk XT, Frog R2/R3


Flow meters with integral data loggers :

•  Transit-time (multi-path) flow meters - Quantum AquaSound
•  Ultrasonic doppler method - Mace Meters
•  Ultrasonic cross correlation method - Nivus
•  Horizontal ADCP - Teledyne RDi with Isodaq Hawk XT or Frog R2/R3
•  Electromagnetic pipe-flow meters - Siemens

We have extensive experience of flow measurement in all types of water environments, and we would be pleased to offer some guidance for budgetary purposes if some specific details of the site and application are provided.  Before selecting the optimum method, we strongly  recommend commissioning a site survey and feasibility study from our flow-measurements specialists at our group company Hydro-Logic Services (International) Limited; please email your enquiry to